Neuroanatomy (AMBOSS)

71 years man -Slurred speech (1 hour ago); drooling and hypernasal speech -Face is symmetric and strength is 5/5 in all extremities -Injury to which part of motor cortex? can't answer= learn a) A b) B c) C d) D e) E

answer: A -Area A= motor innervation of muscles of throat, involved in swallowing, as well as tongue, mastication, and vocalization -Slurred speech and drooling are signs of injury to this area option B= facial expression option C= movement of index finger option D= movement of wrist option E= movement of toe

17 years boy -Stabbed with knife (stab wound on right lateral border of T1 spinous process) -MRI= damage to right lateral corticospinal tract at T1 -Findings? a)Absence of left-sided proprioception below T1 b)Absence of right-sided temperature sensation below T1 c)Presence of left-sided Babinski sign d)Absence of left-sided fine touch sensation below T1 e)Absence of right-sided motor function below T1

answer: Absence of right-sided motor function below T1 -Right lateral corticospinal tract injury (e.g., partial Brown-Sequard syndrome) would result in absence of ipsilateral motor function below level of injury -Lateral corticospinal tract decussates at the level of medulla -In full Brown-Sequard syndrome (e.g., Hemisection of the spinal cord)= -1) ipsilateral loss of all sensation AT level of lesion -2) ipsilateral LMN signs (e.g., flaccid paralysis) AT level of lesion (anterior horn) -3) ipsilateral UMN signs BELOW level of lesion (due to corticospinal tract damage) -4) ipsilateral loss of proprioception, vibration, light (2-point discrimination) touch, and tactile sense BELOW level of lesion (due to dorsal column damage) -5) contralateral loss of pain, temperature and crude (non-discriminative) touch 1-2 levels BELOW level of lesion (due to spinothalamic tract damage) -If damage above T1= ipsilateral Horner syndrome option A and D= left dorsal column; decussate at medulla option B= left lateral spinothalamic tract; ascend 1-2 levels before decussating at anterior white commissure option C= UMN lesion; left lateral corticospinal tract

54 years man -Hit by a car -Left-sided tonic-clonic seizure and one episode of vomiting -Exam: flaccid paralysis of all extremities -CT: M shaped hyperintense lesion in the basal cistern -Hemorrhage where? a)Into the ventricular system b)Between the dura mater and the arachnoid mater c)Between the skull and the dura mater d)Into the cerebral parenchyma e)Between the arachnoid mater and the pia mater

answer: Between the arachnoid mater and the pia mater -Traumatic brain injury can cause subarachnoid hemorrhage (bleeding b/w arachnoid mater and pia mater) -Sudden, severely painful headache, vomiting, loss of consciousness, and in case of severe hemorrhage= seizures -CT= M shaped hyperintense signal in the basal cistern (in center of CT) -Most common cause= rupture of saccular aneurysm option A= intraventricular hemorrhage, typically secondary to intracerebral or subarachnoid hemorrhage but can arise from rare vascular malformations; headaches, vomiting, and altered consciousness; CT=bleeding in ventricles option B= subdural hematoma= rupture of bridging veins; headache and signs of increased ICP following head trauma; CT= high-density crescent shaped collection (in acute cases) or hypodense crescent shaped collection (in chronic and subacute cases) across hemispheric convexity, which crosses the suture lines option C= epidural hematoma; fracture of pterion= rupture of middle meningeal arteries; causes loss of consciousness, lucid interval and subsequent loss of consciousness and signs of increased ICP; CT= lentiform hemorrhage that doesn't' cross suture line option D= intracerebral hemorrhage; caused by spontaneous rupture of vessels secondary to structural changes of vessel walls (e.g., chronic hypertension, cerebral amyloid angiopathy); patients often present with headache and focal neurologic symptoms

55 years man -Speaks slowly in simple sentences that consist of only one word -Difficulties understanding grammatically complex sentences and appears to be frustrated at inability to speak fluently -He is able to follow commands -Injury to? a) premotor cortex b) primary motor cortex c) primary somatosensory cortex d) Broca area e) primary auditory cortex f) Wernicke area g) primary visual cortex

answer: Broca area -Broca aphasia -Nonfluent speech with constant repetition of one word, in combination with preserved comprehension of simple sentences and commands -Aware of their lesion option A= premotor cortex; difficulty of planning, initiating, and maintaining muscle movements; can cause verbal apraxia (difficulty to execute motor movements needed to produce speech)= halting speech and speech sound distortions and errors option B= primary motor cortex= contralateral hemiplegia and hemiparesis as well as dysarthria= slurring, mumbling and changes in speed and pitch option C= primary somatosensory cortex= contralateral numbness, tingling and partial sensory loss option E= primary auditory cortex; difficulty in sound localization and subtle hearing dysfunction= unilateral; if bilateral= cortical deafness with complete loss of comprehension option F= Wernicke area= Wernicke aphasia, impaired comprehension, neologisms, long and grammatically correct but nonsensical sentences, and lack of insight regarding the condition option G= primary visual cortex= cortical blindness with macular sparing

-age: 21 years woman -posterior arthrodesis for thoracolumbar scoliosis -After= difficulties combing her hair with right hand -Winged scapula -Nerve most likely injured in surgery originates from? a)C8-T1 b)C6-C8 c)C1-C3 d)C3-C5 e)T2-T5 f)C5-C7

answer: C5-C7 -Picture shows winging of scapula= long thoracic injury -Long thoracic nerve (C5-C7), enters axillary cavity, and descends together with the lateral thoracic artery along with the lateral surface of the thoracic cage -Injury= paralysis of serratus anterior= medial winging of scapula and weakened abduction of shoulder above 90 degrees -Other causes: axillary lymph node dissection, direct trauma to the shoulder, and prolonged nerve compression (e.g., carrying a heavy backpack) option A= lower trunk of brachial plexus and ulnar nerve; lower brachial plexus palsy (Klumpke's palsy)= weakness of all intrinsic muscles of the hand, and sensory deficits on medial side of upper limb; ulnar nerve injury= weakness of 4th and 5th lumbricals and sensory deficits of 4th and 5th digits option B= thoracodorsal nerve; axillary lymph node dissection; weakness of latissimus dorsi and teres major; impaired internal rotation and adduction of the arm option C= ansa cervicalis; in carotid triangle of neck and primarily innervates infrahyoid muscles; damage during neck dissection or trauma to cervical spine= change in voice and swallowing difficulties option D= phrenic nerve; innervates diaphragm, pericardium and shoulder; injury during anterior scalenectomy, open heart or thoracoscopic mediastinal surgery, pulmonary vein radiofrequency ablation, IVC clamping during hepatectomy or liver transplantation; manifests as dyspnea, shoulder pain option E= corresponding intercostal nerves and innervate corresponding intercostal muscles; 2nd-5th also innervate serratus posterior superior muscle; injury during placement of a chest drain or thoracotomy; neuralgic pain, accessory respiratory muscles so respiration isn't affected much

52 years man -Subtotal gastrectomy -Unilateral atrophy of the neurons in fasciculus gracilis -Findings? a)Decreased sense of pain in the contralateral leg b)Decreased sense of temperature in the ipsilateral arm c)Decreased strength of the contralateral leg d)Decreased vibratory sense in the ipsilateral arm e)Decreased positional sense in the ipsilateral leg f)Decreased sense of crude touch in the contralateral arm

answer: Decreased positional sense in the ipsilateral leg -Fasciculus gracilis= afferent neurons, transmit proprioception, vibration, pressure and fine touch from ipsilateral lower trunk and extremities -Atrophy due to neuronal demyelination (vitamin B12 deficiency or tabes dorsalis) option A and B= lateral spinothalamic tract= decreased sensitivity of pain/temp. on ipsilateral side of body at level of lesion and on contralateral side two segments below lesion option C= lateral corticospinal= decussate in medulla option D= fasciculus cuneatus option F= anterior spinothalamic tract; atrophy= decreased sensitivity to crude touch/pressure on ipsilateral side at lesion; or contralateral side two segments below lesion

44 years woman -MRI= hyperintense mass with extension into the right foramen rotundum -Findings? a)Decreased sensation over the cheekbone, nasolabial fold, and the upper lip b)Hemiatrophy of the tongue with right-sided deviation when protruded c)Abnormal taste of the distal tongue and decreased sensation behind the ear d)Absent corneal reflex and decreased sensation of the forehead e)Masseter and temporalis muscle wasting with jaw deviation to the right

answer: Decreased sensation over the cheekbone, nasolabial fold, and the upper lip -CN V2= sensation to middle third of face (i.e., cheekbone, nasolabial fold, upper lip) -Foramen rotundum then infraorbital canal then infraorbital foramen option B= right CN XII; exits via hypoglossal foramen option C= facial nerve palsy; passes through internal acoustic meatus and exits skull via stylomastoid foramen option D= CN V1; afferent limb of corneal reflex; superior orbital fissure option E= CN V3; deviation of jaw towards injured side; foramen ovale

78 years man -Visual field test: bilateral right upper quadrant vision loss -Lesion in? dont answer, learn a) A b) B c) C d) D e) E f) F g) G

answer: E -Meyer loop -Contralateral superior homonymous quadrantanopia -Etiologies: stroke involving the MCA (temporal lobe) option A= left optic nerve damage= left eye blindness option B= damage of fibers from temporal part of left retina= nasal hemianopia of left eye option C= optic chiasm= bitemporal hemianopia; injury causes= pituitary adenoma, pituitary apoplexy, and saccular aneurysms option D= left optic tract= right homonymous hemianopia option F= left dorsal optic radiation= contralateral lower homonymous quadrantanopia; causes: lesions of parietal lobe, involving MCA stroke option G= left central bundle of optic radiation= contralateral homonymous hemianopia with macular sparing (PCA infarct)

62 years man -Hypertension and atrial fibrillation -High BP and pulse -He is alert and oriented to person but doesn't follow commands -His speech is fluent, but uses frequent non-existent words and the content of his speech is nonsensical -Unaware of his speech impairment; unable to read text out loud -Peripheral vision= diminished in right upper visual fields bilaterally -Injury to which labelled area? dont answer, learn a) A b) B c) C d) D e) E

answer: E -Receptive aphasia, right upper homonymous quadrantanopia, and CVA risk factors= stroke due to occlusion of inferior division of left MCA -Stroke to superior temporal lobe -Visual field defects= left optic radiations (Meyer loop) in temporal lobe option A= hippocampus; ischemic injury= anterograde amnesia option B= internal capsule; lacunar infarcts= contralateral hemiparesis or hemiplegia, dysarthria and dysphagia option C= insula; involved in perception, somatosensory processing, visceromotor functions, and cognition; ischemic injury= variable symptoms, most commonly associated with nonfluent aphasia; vestibular, motor, somatosensory, and/or cardiac abnormalities option D= inferior frontal gyrus; Broca aphasia

72 years man -Hoarseness, exertional dyspnea, fatigue -Irregular pulse; coarse voice -Exam: soft diastolic murmur heard best at apex -Cause? a)Carcinoma arising from the mucosa of the larynx b)Extrinsic impingement of the recurrent laryngeal nerve c)Bacterial infection of the vocal folds d)Occlusion of the posterior inferior cerebellar artery e)Laryngeal inflammation due to chemical irritant f)Circulating acetylcholine receptor antibodies

answer: Extrinsic impingement of the recurrent laryngeal nerve -Diastolic murmur at apex= mitral stenosis -Left recurrent laryngeal nerve= around arch of aorta -Massive enlargement of left atrium (and potentially pulmonary artery) in patients with mitral stenosis= compress RLN= hoarseness (Ortner syndrome) option A= SCC arising from laryngeal mucosa= hoarseness, fatigue, dyspnea due to lung metastases; wouldn't explain diastolic murmur and atrial fibrillation option C= laryngitis with bacteria like Moraxella catarrhalis, H. influenzae, S. pneumoniae= hoarseness and fatigue; wouldn't cause murmur option D= lateral medullary syndrome option E= GERD option F= myasthenia gravis= fluctuating fatigue, weakness, hoarseness, stridor, and rarely dyspnea; diplopia and ptosis; wouldn't account for diastolic murmur

31 years man -Painless lump near left wrist and tingling pain over his left hand -Exam: transilluminating, rubbery, fixed, non-tender mass over lateral volar aspect of left wrist -Decreased sensation to pinprick on thumb, index finger, middle finger, and radial half of ring finger -Tingling pain is aggravated by tapping over the swelling -Adjacent structures at risk of entrapment if this mass persists? a)Ulnar artery b)Extensor pollicis brevis tendon c)Flexor pollicis longus tendon d)Flexor carpi radialis tendon e)Ulnar nerve

answer: Flexor pollicis longus tendon -Transilluminating, firm mass over the wrist= ganglion cyst -Decreased sensation and paresthesia in the median nerve distribution along with a positive Tinel's sign (tingling sensation) indicate that the cyst is in a location where it is causing compression of the carpal tunnel (e.g., carpal tunnel syndrome) -flexor pollicis longus tendon travels through the carpal tunnel with the median nerve -Other structures in carpal tunnel: four tendons of the flexor digitorum profundus and four tendons of the flexor digitorum superficialis option A= not in carpal tunnel; and its resistant to soft tissue masses b/c its an artery option B= runs along radial aspect of wrist, midway between the volar and dorsal surfaces option D= runs radial and outside the carpal tunnel option E= runs in the Guyon canal

24 years man -MVA; pain in right shoulder -Bruising and tenderness below right coracoid process -Unable to flex right elbow or supinate the right forearm -Decreased sensation to light touch over anterolateral forearm -Location of injury? a) upper trunk of brachial plexus b) lower trunk of brachial plexus c) long thoracic nerve d) posterior cord of brachial plexus e) axillary nerve f) radial nerve g) musculocutaneous nerve h) median nerve i) ulnar nerve

answer: G -No elbow flexion or supination of forearm, loss of sensation in anterolateral arm= musculocutaneous nerve (C5-C7; lateral cords) option A= upper trunk of brachial plexus (C5-C6)= Erb's palsy= impaired flexion and supination of forearm; external rotation, abduction and wrist extension; impaired sensation= lateral arm to the thumb option B= lower trunk of brachial plexus (C8-T1)= Klumpke's palsy (hyperabduction trauma)= claw hand, impaired= flexion of MCP with inability to extend the DIP and PIP joints; impaired sensation= little finger, medial surface of forearm and arm option C= long thoracic nerve (C5-C7); in axillary lymph node dissection or mastectomies; impaired serratus anterior muscle= winged scapula= impaired abduction beyond 90 degrees option D= posterior cord of brachial plexus (C5-T1); radial (extensors of arm) and axillary nerves (deltoid and teres minor)= wrist drop (Radial) and arm abduction above 15 degrees and decreased sensation over lateral upper arm (axillary) option E= axillary nerve (C5-C6); surgical neck fractures of humerus= deltoid muscle= loss of abduction of arm and sensation over deltoid option F= radial nerve (C5-T1); midshaft humeral fracture or prolonged axillary compression= Saturday night palsy= wrist drop, weakened hand grip and loss of sensation over posterior aspect of upper limb option H= median nerve (C5-T1); supracondylar fractures of humerus; impaired wrist pronation and flexion; abduction of index and middle finger; thumb opposition (hand of benediction, ape hand deformity)= sensory loss over index and middle finger and radial side of ring finger (palmar surface) option I= ulnar nerve (C8-T1)= fractures of medial epicondyle of numerus or hook of hamate; impaired flexion of ring and little finger (ulnar claw deformity); loss of sensation over little finger and medial side of ring finger

25 years man -Numbness in his left lower extremity -Fracture of neck of the left fibula -Treated with immobilization in a plaster cast -Exam will show? a)Impaired dorsiflexion of the foot b)Loss of sensation over the medial calf c)Inability to stand on tiptoes d)Decreased ankle reflex e)Loss of sensation on the sole of the foot f)Inability to invert the foot

answer: Impaired dorsiflexion of the foot -common peroneal nerve runs close to lateral aspect of fibular head, makes it susceptible to damage due to fracture of fibular neck, tight casts, crossing of the legs, or protracted squatting -Function: dorsiflexion and eversion -Dorsiflexion: tibilias anterior, extensor hallucis longus, extensor digitorum longus and peroneus tertius= innervated by deep peroneal nerve option B= saphenous nerve, branch of femoral nerve option C= tibial nerve injury; innervates gastrocnemius and soleus option D= S1-S2 injury or tibial nerve injury option E= tibial nerve; damaged in deep lacerations to posterior leg or severely displaced tibia fracture option F= injury to tibialis posterior muscle, innervated by tibial nerve

62 years woman -Decreased vision and worsening headaches -Hypertension and hypercholesteremia -Visual field testing: right homonymous hemianopia with macular sparing -cause? a)Degeneration of the macula b)Impaired perfusion of the retina c)Occlusion of the posterior cerebral artery d)Occlusion of the anterior inferior cerebellar artery e)Embolism to middle cerebral artery f)Occlusion of anterior cerebral artery

answer: Occlusion of the posterior cerebral artery -Visual field testing= right homonymous hemianopia with macular sparing -Occlusion of PCA (usually due to emboli from vertebral vessels, aorta, or heart) -Macula sparing= collateral MCA supply option A= age-related macular degeneration; divided into wet and dry AMD; causes gradual loss of central vision and metamorphopsia (straight lines appear wavy) in affected eyes option B= central retinal artery occlusion; caused by cardiac emboli in young patients and carotid atherosclerosis in older patients; presents with painless visual loss in affected eye; usually unilateral option D= lateral pontine syndrome; manifests with vomiting, vertigo, nystagmus, ipsilateral cerebellar ataxia, Horner syndrome, facial muscle paralysis (LMN type), and sensorineural hearing loss, contralateral hemisensory loss option E= contralateral homonymous hemianopia; contralateral limb weakness, and sensory loss (mostly in upper extremities option F= contralateral limb weakness and sensory loss affecting lower limbs mostly; primitive reflexes can re-emerge

78 years man -Difficulty swallowing and regurgitation of undigested food (worsening) -Exam: halitosis and gurgling sound after swallowing water -Fluoroscopic barium esophagography= Zenker's diverticulum -Nerve responsible for innervation of affected muscle also has what function? a)Parasympathetic innervation of the AV node b)Sensory innervation of the posterior tongue c)Visceral sensory innervation of the carotid sinus d)Motor innervation of the ventral tongue e)Somatosensory innervation of the semi-circular canals

answer: Parasympathetic innervation of the AV node -presentation= Zenker's diverticulum (outpouching of esophagus between 2 parts of inferior pharyngeal constrictor (Killian triangle) -Inferior pharyngeal constrictor= innervated by branches from the pharyngeal plexus of CN X -CN X sends parasympathetic fibers to innervate both the SA node (right CN X) and AV node (left CN X) -Additional functions: cough reflex, innervation of taste receptors of the supraglottis, innervation of chemo and baroreceptors of the aortic arch option B and C= CN IX; also, part of pharyngeal plexus and provides motor innervation to the stylopharyngeus option D= CN XII option E= CN VIII

9 years boy -Clumsiness, falls, increased urinary frequency (2 months) -Bilateral temporal visual field loss -MRI= small calcified suprasellar mass -Histology: lobular tumor composed of cysts filled with oily, brownish-yellow fluid -Derived from? a)Rathke pouch b)Primitive neuroectoderm c)Arachnoid cells d)Astroglial cells e)Lactotroph cells f)Ventricular ependyma

answer: Rathke pouch -Craniopharyngiomas are derived from remnants of Rathke pouch (ectodermal outpouching of the pharyngeal roof that develops into the anterior pituitary gland) -Compression of optic chiasm= bitemporal hemianopsia and possible clumsiness or frequent tripping -Destruction of posterior pituitary by the tumor= central diabetes insipidus (explains increased urinary frequency) option B= medulloblastomas, most common malignant tumor in children; can cause clumsiness, frequent falls and urinary symptoms; occurs in cerebellum; raised ICP (headache, vomiting, papilledema) and ventriculomegaly (obstructive hydrocephalus); biopsy= small blue cells arranged around a neuropil (Homer-Wright rosettes) option C= meningiomas; parasagittal meningioma can cause falls, clumsiness (due to spastic lower limb weakness) and urinary symptoms; typically, in adults; histology= densely packed syncytial tumor cells arranged in whorls, interspersed spindle cells and psammoma bodies option D= pilocytic astrocytoma; most common tumor in childhood; clumsiness, frequent falls, urinary symptoms; located in cerebellum; raised ICP symptoms and ventriculomegaly (obstructive hydrocephalus; biopsy= Rosenthal fibers, which stain GFAP+ option E= prolactinomas; urinary frequency, bitemporal hemianopia, and history of clumsiness and frequent falling; features of hyperprolactinemia; and mostly in adults; histology= acidophilic lactotrophs option F= ependymoma; line walls of cerebral ventricles; can cause hydrocephalus (could present with clumsiness, frequent falls and urinary symptoms); usually in 4th ventricle and symptoms of raised ICP; histology= perivascular pseudorosettes and rod-shaped belpharoplasts (basal ciliary bodies

78 years man -Sensation to light touch and pinprick is decreased on right side -CT= acute infarction in distribution of left posterior cerebral artery -Findings? a)Left-sided hemineglect b)Right-sided homonymous hemianopia c)Left-sided gaze deviation d)Prosopagnosia e)Right-sided superior quadrantanopia

answer: Right-sided homonymous hemianopia -PCA= parts of thalamus, visual cortex -Contralateral hemisensory loss (lateral thalamic infarction) -Contralateral homonymous hemianopia with macular sparing (collaterals from MCA) option A= right parietal lobe= right MCA option C= left MCA, which supplies the frontal eye field option D= right PCA= right occipitotemporal lobe option E= lesion in left optic radiation= strokes involving left MCA

5 years boy -Irregular gait (3 days after vaccine) -When child stands on his right leg, his left leg drops and his pelvis tilts towards the left -Injection of vaccine where? a)Superomedial quadrant of the left buttock b)Inferolateral quadrant of the right buttock c)Inferomedial quadrant of the right buttock d)Inferomedial quadrant of the left buttock e)Superomedial quadrant of the right buttock f)Inferolateral quadrant of the left buttock

answer: Superomedial quadrant of the right buttock -Superior gluteal nerve lies in this quadrant= innervates gluteus medius, minimus and tensor fasciae latae -Injury to right SGN= pelvis tilts towards left while standing on right leg (positive Trendelenburg sign) -IM injections usually given in superolateral quadrant of buttock to avoid nerve injury option A= opposite signs option B= right sciatic nerve; high-stepping gait, foot drop, weakened knee flexion, and sensory loss over the foot and lateral surface of the lower leg option C= right sciatic nerve and right inferior gluteal nerve; inferior gluteal nerve= backward lurching gait; impaired hip extension and forward pelvic tilt while standing on affected side option D= opposite of C option F= opposite of B

55 years woman -Left-sided tinnitus; tumor of left jugular fossa -Sialometry= decreased production of saliva from the left parotid gland -Additional findings? a)Protrusion of the tongue b)Taste sensation of tip of the tongue c)Closing of the jaw d)Afferent limb of the gag reflex e)Afferent limb of the cough reflex f)Equilibrium and balance

answer: afferent limb of the gag reflex -Most common tumor of jugular foramen= paraganglioma (glomus jugulare)= typically presents with pulsatile tinnitus -Parotid gland is innervated by tympanic branch of CN IX, which exits the skull at the jugular foramen (posterior to jugular fossa) -Afferent limb of gag reflex is formed by the CN IX and efferent limb is formed by CN X -Upon irritation of the posterior pharyngeal wall, reflex elicits elevation of the soft palate and bilateral contraction of the pharyngeal muscles option A= CN XII option B= CN VIII option C= CN V3 option E= superior laryngeal nerve of CN X option F= CN VIII

55 years man -Abnormal behavior (3 weeks) -Treated for HSV-1 encephalitis -Eating increasing volumes of food (and non-food items) -Rubs his genitals on furniture; touching his genitals and masturbating in public -Patient appears docile -Exam: ability to follow motor commands but inability to name objects -Damage to? a)Subthalamic nuclei b)Amygdalae c)Hippocampi d)Frontal lobe e)Mamillary bodies

answer: amygdalae -Bilateral damage of medial parts of anterior temporal lobe (including the amygdalae)= Kluver-Bucy syndrome -HSV-1 encephalitis is most common cause of KBS -Symptoms: hyperorality, hyperphagia, docility, cognitive dysfunction, visual agnosia, hypersexuality -Diagnosis= MRI (most sensitive; early stages)= bilateral hyperintense temporal lobe lesions -Other causes of KBS: head trauma, stroke, malignancy, neurodegenerative diseases (e.g., Alzheimer, Pick, Parkinson and Huntington) option A= disinhibited behavior (i.e., hyperorality, hyperphagia and hypersexuality) and visual agnosia; would also cause characteristic contralateral hemiballismus option C= disinhibited behavior and visual agnosia, but also anterograde amnesia option D= hypersexuality and deficits in judgement; re-emergence of primitive reflexes, Broca aphasia, urinary incontinence, deficits in conjugate horizontal gaze (frontal eye field), and frontal gait disorder option E= confusion, disorientation, inattentiveness; ataxia and ophthalmoplegia (i.e., Wernicke encephalopathy) with or without amnesia (anterograde> retrograde) and confabulation (Korsakoff syndrome); associated with vitamin B1 deficiency

32 years man -Lifted heavy weights at gym -Exam: loss of sensation on lateral side of right forearm, sensation over thumb is intact -Range of motion of neck is normal; symptoms do not worsen on axial compression or distraction of the neck -Further examination? a)Shoulder abduction b)Elbow flexion c)Forearm pronation d)Index finger flexion e)Wrist extension f)Pincer grip

answer: elbow flexion -Musculocutaneous nerve= innervates biceps brachii and brachialis muscles -Cause: lifting heavy weights -Impairs elbow flexion and forearm supination and biceps tendon reflex -The normal range of motion in neck and negative Spurling sign indicate this patient has a peripheral nerve injury option A= predominantly axillary nerve; by deltoid muscle; also controls sensation over deltoid option C= pronator teres and pronator quadratus muscles, innervated by median nerve; also controls sensation on lateral aspect of the palm, including the thumb option D= median nerve option E= radial nerve; controls sensation over posterior surface of forearm extending to dorsolateral hand option F= ulnar nerve, also controls sensation of medial aspect of hand

70 years man -One hour after surgical repair of thoracic aortic aneurysm -Pain at thoracolumbar junction and weakness and numbness of both legs -Exam: decreased sensation to pain and temperature below level of umbilicus, muscle strength is 1/5 in bilateral lower extremities; proprioception and vibration sense are normal in both lower extremities -Sensation and motor function in upper extremities, chest, and back are intact -Diagnosis? a)Leriche syndrome b)Anterior cord syndrome c)Brown-Sequard syndrome d)Central cord syndrome e)Posterior cord syndrome f)Spinal epidural hematoma

answer: anterior cord syndrome -Anterior cord syndrome: Damage to anterior 2/3 of spinal cord -Manifestations: 1) bilaterally, LMN deficit at level of damage (anterior horn) 2) decreased pain and temperature sensation (spinothalamic tract) below level of lesion 3) UMN deficit (lateral corticospinal tract) below level of lesion -Cause: complication of aortic aneurysm itself or iatrogenically during repair of aneurysm (due to damage of anterior spinal artery and/or artery of Adamkiewicz) -Thoracolumbar segment is a watershed area= most common site of infarction -Other causes: trauma (e.g., penetrating injury), hypotension (e.g., from severe hemorrhage), and compression (e.g., tumors, cervical spondylosis) -May also experience bowel and bladder dysfunction due to bilateral damage to lateral horns of spinal cord option A= aortoiliac disease; peripheral artery disease at level of aortic bifurcation or bilateral occlusion of iliac arteries. Manifestations: triad of thigh/hip claudication, erectile dysfunction and absent/diminished femoral pulses option C= Hemisection of the spinal cord. Manifestations: 1) ipsilateral loss of proprioception, fine touch, and vibration (dorsal column) at level of lesion 2) contralateral loss of pain and temperature (spinothalamic tract) at level of lesion 3) ipsilateral LMN deficit at level of lesion (anterior horn) 4) ipsilateral UMN deficit below level of lesion (corticospinal tract option D= bilateral loss of pain and temperature sensation (anterior white commissure) and bilateral paresis of extremities (lateral corticospinal tracts); usually in upper extremities, and pain and temperature loss in cape-like distribution across upper back, and down the posterior upper extremities option E= dorsal columns; loss of proprioception, fine touch and vibration below level of lesion option F= acute spinal cord compression, manifest as back pain and lower extremity weakness and numbness; occurs following puncture of the dura mater that causes damage to the vertebral venous plexus (e.g., following lumbar puncture, after pulling a dural catheter) rather than following aortic aneurysm repair

67 years man -Sudden left sided body weakness and difficulty speaking -History: hypertension and coronary artery disease; smoker (30 years) -BP is high, exam: deviation of tongue to right, left-sided hemiparesis and decreased proprioception of left side of body -Occlusion of which vessel? a) right MCA b) right PCA c) anterior spinal artery d) left superior cerebellar artery e) basilar artery f) left anterior inferior cerebellar artery

answer: anterior spinal artery -Paramedian branches of anterior spinal artery or vertebral artery= medial medullary syndrome -1) right CN XII (right tongue deviation) 2) right corticospinal tract (left hemiparesis) 3) right medial lemniscus (left sided loss of proprioception) -CAD+ hypertension + smoking= thrombotic stroke, caused by plaque rupture in atherosclerotic arteries option A= right MCA; left sided hemiparesis and sensory loss (mainly upper limbs and face); difficulty speaking (labial dysarthria, caused by UMN CN VII palsy); horizontal gaze deviation; left homonymous hemianopia and left hemineglect option B= right PCA; supplies rostral midbrain, thalamus, occipital lobe and inferomedial temporal lobe ipsilaterally; left-sided sensory loss (right thalamus), left-sided hemiparesis (right corticospinal tracts); left homonymous hemianopia with macular sparing, memory deficits and vertigo option D= left superior cerebellar artery= superior cerebellar peduncle, anterior cerebellar lobe and part of lateral tegmentum= difficulty speaking (ataxic dysarthria), sensory deficits (occasionally, on right side) due to involvement of left spinothalamic tract (pain and temperature); vertigo, nystagmus, dysmetria and Horner syndrome option E= basilar artery; most severe= locked in syndrome= quadriplegia and bulbar palsy with preserved consciousness, blinking and vertical eye movements option F= left anterior inferior cerebellar artery= lateral pontine syndrome= CN VII, vestibular nucleus, spinothalamic tract, spinal trigeminal nucleus, hypothalamospinal tract, middle and inferior cerebellar peduncles= difficulty speaking (labial dysarthria) and sensory deficits (pain and temperature on right side), Horner syndrome, vertigo, ataxia

69 years man -Progressive hearing loss -Hearing worse in crowded rooms -More difficulty understand women than men -Air conduction is greater than bone conduction bilaterally -Damage to? a)External acoustic meatus b)Tympanic membrane c)Basal turn of the cochlea d)Helicotrema e)Round window f)Base of the stapes

answer: basal turn of the cochlea -Sound waves cause vibrations that resonate with the basilar membrane of the cochlea, which converts this input into neural signals that encode auditory information -Base of cochlea, including basal turn= responds to higher frequencies (e.g., women's voices) -Progressive degeneration of the organ of Corti near this region= presbycusis (most common type of hearing loss in adults) -Sound conduction is unaffected= Rinne test is normal (air conduction is greater than bone conduction bilaterally option A= conductive hearing loss; Rinne test would be abnormal (bone conduction> air conduction) option B= conductive hearing loss option D= near apex of cochlea; low frequency hearing loss like men's voices option E= acute changes in perilymphatic pressure (e.g., from loud noises or during diving, violent nose-blowing, or lifting heavy weights)= rupture round window= sensorineural hearing loss; however, onset would be acute, asymmetrical, independent of sound frequency, and typically associated with tinnitus and vertigo option F= conductive hearing loss; otosclerosis is most common cause

-Investigation of anterior horn of spinal cord of a patient involved in snowboard accident -Pathology: dispersion of the Nissl bodies, swelling of the neuronal body, and a displacement of the nucleus to the periphery -Explanation? a)Neurodegenerative changes b)Early ischemic damage c)Wallerian degeneration d)Central chromatolysis e)Reactive astrogliosis f)Neuronal aging

answer: central chromatolysis -Central chromatolysis is a reaction of neuronal cell body (also known as soma) in response to axonal injury -Characterized by 1) swelling of neuronal body 2) dispersion of Nissl bodies 3) displacement of nucleus to periphery -The changes reflect an increase in protein synthesis aimed at restoring the integrity of damaged axon -Chromatolysis occurs concurrently with Wallerian degeneration option A= occurs in response to loss of function and structure of neurons in neurodegenerative diseases (e.g., Parkinson, Alzheimer, Huntington) option B= manifests with retraction of the cellular outlines, pyknosis, disappearance of Nissl bodies, and eosinophilic condensation of the cytoplasm option C= process that occurs in response to a proximal axonal or neuronal cell body injury; characterized by degeneration of the distal segment of the transected nerve fiber and axonal retraction proximally option E= nonspecific reactive change in response to damage in the CNS; proliferation of various glial cell lineages; response to control oxidative damage to the remaining neurons, quickly re-establish BBB, and to lay down scar tissue option F= characterized by lipofuscin deposition in neuronal cell body

43 years woman radial nerve injury impaired movement? a)Extension of the wrist and fingers b)Opposition of thumb c)Flexion of the metacarpophalangeal joints d)Flexion of the forearm e)Abduction of the shoulder above 100 degrees

answer: extension of the wrist and fingers -Radial nerve= posterior cord of brachial plexus (C5-T1) -Motor innervation to triceps and muscles in posterior compartment of forearm (including all wrist and hand extensors) -Injury= wrist drop, as well as loss of sensation of posterior forearm and dorsal hand option B= injury to median nerve; innervates forearm flexors, thenar muscles (necessary for thumb opposition), radial lumbrical muscles of the hand; from medial and lateral cords (C5-T1) option C= ulnar nerve palsy; also, impairs extension at the proximal interphalangeal joint of the little and ring fingers (ulnar claw); medial cord (C8-T1) option D= and supination of forearm= musculocutaneous nerve (innervates biceps brachii, brachialis, coracobrachialis; lateral cord (C5-C7) option E= 1) long thoracic nerve; spinal nerve roots (C5-C7); innervates serratus anterior 2) coordinated shoulder abduction also relies on axillary (deltoid muscle), suprascapular (supraspinatus) and accessory nerves (trapezius muscle)

72 years woman -Sudden-onset neck pain, nausea, vomiting and difficulty walking -Cannot sit upright without propping herself up on her hands -High BP; exam: downbeat nystagmus, neck stiffness, head bobbing, broad-based gait -Unable to perform a balance test or Romberg test -injury to? a)Posterior spinal cord b)Pyramidal tract c)Cerebellar vermis d)Flocculonodular lobe e)Frontal lobe f)Cerebellar hemisphere

answer: cerebellar vermis -Cerebellar vermis= coordination of vestibular system, eye movements, balance and complex sequential movements -Downbeat nystagmus, head bobbing, and truncal ataxia (inability to sit upright without propping herself up on her hands)= cerebellar vermis injury -Lesions in medial cerebellum (vermis, flocculonodular lobe and corresponding deep nuclei)= affect medial structures of body (e.g., axial and proximal limbs)= truncal ataxia and nystagmus -Lesions in the lateral parts of cerebellum (hemispheres) affect lateral structures of the body (e.g., distal limbs)= ipsilateral limb ataxia option A= dorsal columns; sensory ataxia that is worse in dimly lit settings, where a patient's proprioception cannot compensate for loss of visual bearings; the patient's broad-based gait and inability to perform a Romberg test are not environment dependent option B= corticobulbar tract injury= pseudobulbar palsy (e.g., dysarthria, dysphagia, lack of facial expression); corticospinal tract injury= contralateral hemiparesis with spasticity, hypertonia, hyperreflexia, Babinski sign option D= regulating balance, ocular movements and gaze stability; can cause head bobbing, truncal ataxia, and nystagmus; but it is an upbeat or rebound nystagmus not downbeat; and usually manifests with vertigo option E= motor function, memory and attention; injury bilaterally= frontal gait= broad-based gait and difficulty with balance; gait problems during walking; and re-emergence of primitive reflexes option F= limb ataxia (e.g., dysmetria, dysdiadochokinesis, hypotonia, intention tremor) affecting ipsilateral side and dysarthria

39 years man -Hearing loss; can't hear beeping of microwave or birds chirping, but can easily hear the pipe organ at church -Works as an aircraft marshaller -Rinne test= air conduction greater than bone conduction bilaterally -Weber test= does not lateralize -Cause? a)Perforation of the tympanic membrane b)Immobility of the stapes c)Compression of the vestibulocochlear nerve d)Rupture of the oval window e)Destruction of the organ of Corti f)Excess endolymphatic fluid pressure

answer: destruction of the organ of Corti -No lateralization of Weber test= both ears affected (towards normal ear= sensorineural loss) -Noise induced hearing loss= destruction of cochlear hair cells (organ of Corti) -Repeated exposure to sounds louder than 85dB, like those this man experiences at work, or even an isolated exposure to extremely loud sounds greater than 140dB can damage organ of Corti -Results in subsequent sensorineural hearing loss that typically affects high-frequency hearing first option A= foreign body trauma, temporal bone fractures, otitis media, barotrauma, blast injury= conductive hearing loss; bone> air option B= otosclerosis= conductive hearing loss option C= acoustic neuromas in NF2; sensorineural hearing loss, bilateral but not isolated to high frequency and would be accompanied by ataxia, dizziness option D= barotrauma; sensorineural hearing loss= not limited to high frequency sounds option F= sensorineural hearing loss in Meniere disease; usually unilateral, and includes aural fullness, episodic vertigo, and tinnitus; usually affects low frequency sounds

53 years man -Sudden onset dizziness, nausea, and left-sided weakness -High BP -Exam: decreased muscle tone and hyperreflexia in right upper and lower extremities -Gait is unsteady, falls to the left when attempting to walk -Finger-to-nose testing shows dysmetria on left side -CT= small lesion in the left lateral pons that involves the nucleus of a cranial nerve that exits the brain at the middle cerebellar peduncle -Additional findings? a)Ptosis and inability to look up with the right eye b)Hoarseness and deviation of the uvula to the right c)Deviation of the tongue to the left when protruded d)Winging of the left scapula and weakness turning the head to the right e)Impaired vision and absent direct pupillary light reflex of the left eye f)Difficulty chewing and deviation of the jaw to the left g)Inability to smell vanilla or coffee

answer: difficulty chewing and deviation of the jaw to the left -Contralateral hemiparesis and ipsilateral limb ataxia= lateral pontine syndrome -CN V exits brain at middle cerebellar peduncle -Its motor nucleus is located in the lateral portion of upper pons -Patient= infract of left lateral pons that involves CN V -CN V3= innervates muscles of mastication (e.g., lateral pterygoid), could be affected and result in difficulty chewing and ipsilateral deviation of jaw option A= (ptosis= weakness of levator palpebrae superioris. Inability to look up= superior rectus muscles; damage to CN III; arise from midbrain option B= lesion of left CN X; arises from medulla option C= left CN XII lesion; arises from medulla option D= weakness of left sternocleidomastoid innervated by left CN XI; arises from upper cervical spine (C1-C5)a)weakness of left sternocleidomastoid innervated by left CN XI; arises from upper cervical spine (C1-C5) option E= lesion of left CN II, transmit info from retina to optic chiasm, continues as optic tract; arises from forebrain option G= CN I; arises from forebrain

62 years woman -Worsening paresthesia in upper limbs -Burned her fingers on hot dishes several times -Involved in motor vehicle accident 3 years ago -Exam: absent temperature sensation with normal fine touch sensation over the upper extremities and chest -Increased risk of developing? a)Exaggerated biceps reflex b)Decreased mini-mental state examination score c)Absent anal wink reflex d)Deviation of the jaw e)Drooping of the eyelid f)Absent knee-jerk reflex

answer: drooping of the eyelid -cape-like dissociated sensory loss typical of a central cord syndrome, most likely a result of syringomyelia secondary to a whiplash injury (hyperextension of neck injury) -Without treatment, expansion of the syrinx can damage descending hypothalamic fibers in the T1 to T4 segments, which carry sympathetic fibers from the hypothalamus to the intermediate horn= Horner syndrome -Ptosis part of triad of Horner syndrome option A= syringomyelia damages LMNs in anterior horn, causes bilateral weakness that can progress to bilateral flaccid paralysis and muscle atrophy= decreased or absent biceps reflex; exaggerated biceps reflex is present in UMN lesions= multiple sclerosis, stroke, tumors, vitamin B12 deficiency, and ALS option B= a)syringomyelia doesn't affect cognition; conditions that do= subacute combined degeneration, paralytic dementia, tabes dorsalis) Absent anal wink reflex (controlled by pudendal nerve arising from S2-S4 option C= syringomyelia doesn't affect CN V3 option F= in lower extremities, expansion of syrinx damages corticospinal tract= hyperactive knee-jerk reflex; b/c UMN lesion

28 years woman -Episiotomy to expedite vaginal delivery (labor) -Anesthesiologist locates the ischial spines by palpating the posterolateral vaginal sidewall and administers anesthetic -3 minutes later, posterior vulva pinching= no pain -Nerve also supplies? a) obturator externus muscles b) skin of lateral thigh c) gluteus medius muscle d) external anal sphincter e) skin of the mons pubis f) detrusor muscle

answer: external anal sphincter -Anesthesiologist performed a pudendal nerve block to reduce sensation from posterior perineum, vulva and lower vagina (during episiotomy or during 2nd stage of labor if epidural anesthesia is no longer feasible) -External anal sphincter, along with external urethral sphincter, levator ani, bulbospongiosus, and ischiocavernosus muscles are motor targets of pudenal nerve -Sensory innervation: perineum, clitoris, labia, and anal canal -The ischial spine is usually used as a landmark for injection to locate the pudendal nerve option A= obturator nerve; small area of skin on medial thigh, as well as gracilis, pectineus, obturator externus, and adductor magnus, longus and brevis muscles; obturator nerve blocks are achieved with anesthetic injection into medial thigh option B= lateral femoral cutaneous nerve option C= superior gluteal nerve; produce muscle paralysis without accompanying anesthesia; also innervates gluteus medius and tensor fasciae latae option E= ilioinguinal nerve and iliohypogastric nerve, as well as genital branch of genitofemoral nerve, not pudendal nerve; ilioinguinal nerve= skin of labia majora, skin of proximal penis and scrotum; iliohypogastric nerve= lateral gluteal region, internal oblique and transverse abdominal muscles; genitofemoral nerve= sensation to proximal and anterior thigh option F= autonomic nervous system; SNS= lower thoracic and upper lumbar segments via hypogastric nerve; PSNS= sacral segments via pelvic splanchnic nerves

26 years man -Accident= decreased taste on right anterior tongue -Following findings? a)Uvula movement b)Facial sensation c)Eyelid closure d)Tongue protrusion e)Parotid gland salivation

answer: eyelid closure -Mediated by CN VII (chorda tympani, taste from anterior 2/3 tongue) -Closing eyelids= orbicularis oculi muscle= like all facial muscles, innervated by CN VII -Facial nerve= innervation of lacrimal gland, submandibular and sublingual glands and stapedius muscle option A= CN X; also, taste and somatosensory fibers to epiglottis; innervates intestines up to splenic flexure; innervates chemo- and baroreceptors of aortic arch, elevating posterior tongue and soft palate during swallowing and cough reflex option B= CN V; provides somatosensation to anterior 2/3 of tongue; CN V3 also responsible for motor function of mastication muscles option D= extrinsic muscles of tongue by CN XII; also innervates intrinsic muscles of tongue; only extrinsic muscle not innervated by CN XII is palatoglossus muscle, which elevates posterior tongue during swallowing option E= CN IX; also, carries somatosensory and taste fibers to posterior tongue; also, somatosensory info for the middle ear and eustachian tube, innervating chemo- and baroreceptors of the carotid body and sinus, innervates pharyngeal muscles and muscles of upper GI tract

21 years woman -Multiple sclerosis; cramps in left leg -Exam: flexion of left hip and increased tone in thigh muscles -Anesthetic block in which nerve would improve symptoms? a)Obturator nerve b)Sciatic nerve c)Inferior gluteal nerve d)Femoral nerve e)Superior gluteal nerve

answer: femoral nerve -Femoral nerve (L2-L4) innervates hip flexors -Blocking femoral nerve= improves hip flexion -adverse effects= 1) loss of knee extension (because nerve innervates quadriceps femoris muscles) 2) loss of sensation in anteromedial thigh (anterior cutaneous branches) and medial lower leg and foot (via saphenous nerve) option A= L2-L4; hip adductors option B= L4-S3; adductor magnus and hamstring muscles (biceps femoris, semitendinosus, semimembranosus): flexion and rotation of knee; extensors of hip option C= L5-S2; gluteus maximus; hip extensor and external rotator option E= L4-S1; gluteus minimus and medius; hip abductors, internal rotators, and external rotators of thigh (if hip is extended) and tensor fasciae latae (participate in hip flexion, but not enough); also stabilize pelvis

64 years man -Intractable hiccups and shortness of breath on exertion -Left shoulder pain; smoker (35 years) -Decreased breath sounds at left lung base -X-ray: 3-cm perihilar mass and elevation of the left hemidiaphragm -Injury to a nerve that also innervates? a)Fibrous pericardium b)Serratus anterior muscle c)Vocal cords d)Ciliary muscle e)C8-T1 dermatome f)Visceral pleura

answer: fibrous pericardium -hiccups, dyspnea, shoulder pain, elevated hemidiaphragm= compression of phrenic nerve (C3-C5) -Compression by mediastinal lung tumor -Motor and sensory supply to ipsilateral hemidiaphragm -Sensory supply to fibrous pericardium and the mediastinal and diaphragmatic pleura -Pericarditis pain is often referred to the shoulder (common innervation by phrenic nerve) option B= long thoracic nerve: C5-C7 option C= recurrent laryngeal nerve option D= sympathetic trunks through the stellate ganglion; apical tumors can cause compression of sympathetic trunks (Horner syndrome) option E= lower brachial plexus option F= innervated by CN X and sympathetic nerves, not phrenic nerve; insensitive to pain; sensitive to stretch only

28 years man -Persistent tingling sensation in the right side of his face (after extraction of an impacted molar) -Exam: decreased sensation of skin over right side of mandible, chin, and anterior portion of tongue -Taste sensation is preserved -Nerve exits via? a)Foramen magnum b)Hypoglossal canal c)Foramen ovale d)Foramen rotundum e)Jugular foramen f)Stylomastoid foramen g)Superior orbital fissure

answer: foramen ovale -Foramen ovale= CN V3, accessory meningeal artery, lesser petrosal nerve, emissary veins -Sensation: ipsilateral skin of mandible, chin, parts of auricle and temple, buccal mucosa, and anterior 2/3 of tongue -Motor= mastication muscles option A= medulla, CN XI, vertebral arteries, spinal arteries, spinal veins option B= CN XII option D= CN V2, meningeal branch of CN V2 option E= CN IX, X, and XI, internal jugular vein option F= CN VII; lesion= peripheral facial nerve palsy option G= CN III, IV, V1, VI, superior ophthalmic vein

62 years man -High BP -CT= lacunar stroke involving left subthalamic nucleus -Findings? a)Cogwheel rigidity b)Dystonia c)Hemiballismus d)Truncal ataxia e)Vertical gaze palsy f)Hemispatial agnosia

answer: hemiballismus -Contralateral hemiballismus and choreiform movements= common symptoms of lacunar infarct of subthalamic nucleus -Cause: reduction in activity of indirect pathway of basal ganglia -Lacunar infarcts are noncortical infarcts (absence of cortical signs) -Subthalamic strokes= ischemic in etiology, and uncontrolled hypertension, diabetes mellitus and significant smoking history are known risk factors option A= Parkinson; loss of dopaminergic neurons in substantia nigra option B= secondary to lesions of the thalamus, putamen, globus pallidus option D= lesions of cerebellar vermis; other signs of cerebellar stroke= dysarthria, dysmetria, oculomotor disorders (nystagmus)) option E= midbrain lesions, e.g., dorsal midbrain syndrome; presents with vertical gaze palsy, dissociation of pupillary response to light and accommodation, and/or convergence-retraction nystagmus option F= lesions to non-dominant parietal cortex, usually right

67 years man -Misplaces his personal belongings and becomes easily confused (worsening) -He is oriented to person, place and time -He vividly recalls memories from his childhood but can only recall 1/3 objects (presented to him after 5 mins) -Damage to? a)Substantia nigra b)Amygdala c)Ventral posterolateral nucleus d)Nucleus accumbens e)Hippocampus f)Superior temporal gyrus

answer: hippocampus -Short term memory loss= earliest sign of Alzheimer disease (most common cause of progressive dementia in USA) -Damage= structures in medial temporal lobe (hippocampus, parahippocampal cortex which are critical for memory formation) option A= a)plays role in initiation of voluntary movements; damage= Parkinson= bradykinesia, tremor and/or rigidity) option B= limbic system= processing of emotions; involvement in AD= emotional lability, depression and/or anhedonia (inability to enjoy experiences that are usually pleasurable option C= thalamus; sensory input from spinothalamic tract, dorsal column to primary somatosensory cortex; the medial dorsal nucleus and anterior thalamic nucleus= involved in memory formation option D= basal forebrain; role in reward pathway; loss of nucleus basalis of Meynert in forebrain= memory loss and cognitive decline in AD option F= in dominant hemisphere= primary auditory cortex and Wernicke area; damage= sensory aphasia

45 years man -MVA; right hip pain and numbness along right thigh -Exam: decreased sensation to light touch over a small area of medial thigh -X-ray= displaced pelvic ring fracture -Findings? a)Sensory deficit of the dorsal foot b)Impaired hip extension c)Impaired dorsiflexion of the foot d)Impaired extension of the knee e)Absent cremasteric reflex f)Impaired adduction of the hip

answer: impaired adduction of the hip -Pelvic ring fracture= common cause of obturator nerve injury -Sensation to medial thigh; and innervation to hip adductor muscles option A= superficial branch of common peroneal nerve option B= sciatic nerve injury; can occur in setting of hip dislocation or hip arthroplasty; innervates semimembranosus, semitendinosus and long head of biceps femoris option C= common peroneal nerve; fibular head fractures or external compression at fibular head; deep branches= sensation to 1st interweb space; common peroneal= sensation to dorsal foot and lateral leg option D= femoral nerve; quadriceps muscles; sensation to anterior thigh and lateral leg and foot option E= genitofemoral nerve; motor innervation to cremasteric muscle; sensory innervation to scrotum in men, mons pubis and labia majora in women and anteromedial thigh

28 years man -Hit in head with baseball bat -Exam: swelling and bruising around the left temple and eye -CT= transverse fracture through the sphenoid bone and blood in the sphenoid sinus -Findings? a)Left homonymous hemianopia b)Inward deviation of the left eye c)Left facial paralysis d)Decreased hearing in the left ear e)Deviation of uvula to the right

answer: inward deviation of the left eye -Inward deviation of the left eye (esotropia) can result from fractures of the sphenoid bone that extend anteriorly through the superior orbital fissure to damage CN VI (most susceptible) -Other nerves that can be damaged= CN III (ptosis with a fixed and dilated pupil), CN IV (ocular extorsion and vertical diplopia) and ophthalmic nerve (absent corneal reflex) -CN VI also vulnerable to: 1) neoplasm (e.g., sphenoid ridge meningiomas) 2) increased ICP (e.g., pseudotumor cerebri, subarachnoid hemorrhage) 3) neovascular pathologies (e.g., cavernous sinus thrombosis, carotid-cavernous fistulas) and 4) infection (e.g., syphilis) option A= right PCA stroke option C= CN VII peripheral palsy; fractures of the petrous part of temporal bone (e.g., transverse temporal bone fractures option D= CN VIII; skull base fractures extending from petrous pyramid of temporal bone into internal acoustic meatus; other signs: CSF otorrhea, hemotympanum, and mastoid ecchymosis; vertigo and horizontal nystagmus option E= CN X; posterior cranial fossa fractures that extend into jugular foramen

58 years man -Episodic coughing whenever he cleans his left ear -No history of hearing loss, tinnitus, or vertigo -Stimulating left ear canal with cotton swab= triggers a bout of coughing -Peripheral lesion of the cranial nerve manifests with? a)Inability to raise ipsilateral eyebrow b)Ipsilateral deviation of the tongue c)Decreased secretion from ipsilateral sublingual gland d)Ipsilateral vocal cord palsy e)Ipsilateral deviation of the uvula f)Ipsilateral sensorineural hearing loss

answer: ipsilateral vocal cord palsy -Posterior external auditory canal= innervated by auricular branch of CN X (responsible for cough reflex) -Ipsilateral vocal cord palsy= lesion of recurrent laryngeal nerve (branch of CN X) -Paralysis of CN X= loss of gag reflex, dysphagia, decreased taste from supraglottic region, ipsilateral paralysis of soft palate, contralateral uvula deviation) option A= CN VII peripheral palsy; also, ptosis, mouth drooping option B= CN XII; could also cause atrophy and fasciculations of tongue option C= chorda tympani of CN VII; also, loss of taste in anterior 2/3 of tongue option E= CN X but contralateral option F= CN VIII; vertigo, horizontal nystagmus

78 years woman -Diagnosis: herpes zoster in right T10 dermatome -Rash resolved= now continuous burning and stabbing pain in affected area -Physician tests patient's pain and temperature sensation on right lower abdomen -Labelled part responsible for transmission? a) left fasciculus gracilis b) left fasciculus cuneatus c) left lateral spinothalamic tract d) left anterior spinothalamic tract e) right anterior spinothalamic tract f) right lateral spinothalamic tract g) right fasciculus cuneatus h) right fasciculus gracilis

answer: left lateral spinothalamic tract -Left spinothalamic tract (anterior spinothalamic tract= crude touch and pressure) -1st order neurons= dorsal root ganglia= axons enter spinal cord and ascend or descend 1-2 segments to form synapses with -2nd order neurons= posterior horn of gray matter= axons cross to contralateral side within the anterior white commissure to ascend contralaterally to the thalamus -Left spinothalamic tract in upper thoracic segment transmits sensations of pain and temperature from right T10 dermatome

51 years woman -Progressively worsening back pain, radiates down the right leg to the lateral side of the foot -No trauma, urinary incontinence or fever -MRI= disc degeneration and herniation at level of L5-S1 -Findings? a)Difficulty walking on heels b)Exaggerated patellar tendon reflex c)Diminished sensation of the anus and genitalia d)Weak achilles tendon reflex e)Diminished sensation of the anterior lateral thigh

answer: weak achilles tendon reflex -Disc herniation between vertebral bodies L5 and S1 is a common cause of S1 radiculopathy -Manifest= weak achilles tendon reflex -S1 also responsible for= sensation of lateral aspect of calf and foot, as well as plantar flexion and eversion option A= foot drop; injury to L4-L5 nerve roots; L5 also= pain extending along the dorsolateral thigh, lateral side of knee, lower leg and dorsum of foot and big toe; L4 also= pain over patella up to inner side of lower leg option B= UMN lesions affecting L4 spinal nerve option C= cauda equina syndrome; involves numerous spinal nerves, L3-S5 option E= L3 nerve injury

69 years man -Right-sided body weakness (1 hour) -Deviation of tongue to the left when protruded and decreased sensation and vibration and position in right extremities -Muscle strength= 2/5 in right lower extremity and 1/5 in right upper extremity -Plantar reflex= extensor response on right side -CT= brainstem lesion; lesion in? a) right medial medulla b) right inferior olivary nucleus c) right lateral medulla d) left lateral medulla e) left inferior olivary nucleus f) left medial medulla

answer: left medial medulla -Area contains left pyramidal tract (descending motor tract) and left medial lemniscus (ascending sensory tract) at the level of the cranial medulla (i.e., level of inferior olivary nuclei) -Medial medullary syndrome (features of UMN hemiparesis): 1) loss of proprioception, vibration and fine touch in contralateral side (i.e., right) 2) contralateral hemiparesis (i.e., right) 3) ipsilateral deviation of tongue (CN XII) -can be caused by occlusion of paramedian branches of anterior spinal artery option A= medial medullary syndrome; but opposite side option B= right inferior olivary nucleus; provides innervation to the contralateral (i.e., left) cerebellar nuclei; cerebellar nuclei control motor coordination in ipsilateral half of body; damage= anterograde transneuronal degeneration of left cerebellar nuclei= left-sided hemiataxia option C= contain right lateral spinothalamic tract, spinal trigeminal nucleus, nucleus ambiguus, vestibular nuclei, and sympathetic fibers; damage= lateral medullar syndrome)= e.g., right sided palate weakness (uvula to left); loss of pain/temperature in contralateral body and ipsilateral face, nystagmus, vertigo and right sided Horner syndrome option D= opposite as C option E= opposite as B

69 years right-handed man -Difficulty speaking for 3 months -Difficulty repeating what his interlocutor has said -Patient speaks fluently in full sentences and demonstrates normal comprehension -Occlusion of branch of which artery? a)Right posterior cerebral b)Left middle cerebral c)Right middle cerebral d)Right penetrating e)Right posterior inferior cerebellar f)Right vertebral g)Left posterior inferior cerebellar h)Left posterior cerebral i)Left vertebral j)Left penetrating

answer: left middle cerebral -Patient can't repeat, can speak and comprehend= conduction aphasia (in supramarginal gyrus, arcuate fasciculus) -Right-handed= supramarginal gyrus is supplied by branch of left MCA= disrupt articular fasciculata option A= left homonymous hemianopia with macular sparing option C= left-sided weakness and hemineglect option D= right posterior limb of internal capsule= left-sided weakness option E= lateral medullary syndrome= Wallenberg syndrome= ipsilateral face and contralateral body pain/temperature deficits; dysphagia, hoarseness, and ipsilateral Horner syndrome option F= dizziness, diplopia, hemiparesis, or numbness option G= opposite of E option H= opposite of A option I= opposite of F option J= opposite of D

28 years man -Symmetric, ascending weakness that started in his feet and become progressively worse over the past 5 days -Lumbar puncture performed -Needle advanced, there is resistance before entering epidural space -Resistance is due to? a)Ligamentum flavum b)Superficial fascia c)Interspinous ligament d)Dura mater e)Supraspinatus ligament

answer: ligamentum flavum -Ascending flaccid paralysis= Guillain-Barre syndrome -Ligamentum flavum forms posterior boundary of epidural space -layers (posterior to anterior)= skin, fascia, subcutaneous fat, supraspinous ligament (1st point of resistance), interspinous ligament, ligament flavum (2nd point of resistance), epidural space, and then dura mater (3rd point of resistance; loss of resistance indicates entry into the subarachnoid space, where CSF is)

61 years woman -Underwent radical mastectomy and axillary lymph node dissection -Unable to comb her hair; can't abduct right arm above 90 degrees -When she pushes against a wall, there is protrusion of medial aspect of right scapula -Injury to? a)Upper trunk of the brachial plexus b)Axillary nerve c)Long thoracic nerve d)Suprascapular nerve e)Thoracodorsal nerve

answer: long thoracic nerve -Long thoracic nerve injury= complication of axillary lymph node dissection -Long thoracic innervates serratus anterior muscle= medial winging of scapula (injury) option A= injured by trauma (e.g., shoulder dystocia during labor); manifests with adducted, extended, pronated, and medially rotated (Erb palsy) option B= injured by trauma (e.g., anterior shoulder dislocation) or iatrogenic damage (e.g., rotator cuff surgery); impairs arm abduction due to paralysis of deltoid muscle, also impairs external rotation (paralysis of teres minor) and sensory deficit over deltoid region option D= paralysis of infraspinatus and supraspinatus= limits adduction, abduction and external rotation of arm, causes shoulder instability option E= innervates latissimus dorsi and teres major muscles; also, can be injured during axillary lymph node dissection; injury= impair shoulder retraction and adduction and internal rotation

25 years man -Deep laceration on the volar surface of the distal left forearm -Loss of abduction and opposition of the left thumb -Radial and ulnar pulses are palpable -Nerve injury? a)Posterior interosseous nerve b)Axillary nerve c)Radial nerve d)Median nerve e)Musculocutaneous nerve f)Ulnar nerve

answer: median nerve -Median nerve laceration at wrist -Loss of thumb abduction and opposition -Additional findings: reduced or absent sensation in thumb, index, middle and radial sided ring fingers option A= terminal branch of radial nerve deep in the dorsal forearm; extension deficits at wrist and fingers option B= deltoid and teres minor; and skin over lateral shoulder; shoulder dislocations or fractures of surgical neck of humerus; weak arm abduction and flattened shoulder option C= mid-shaft humerus fracture= extension deficits at elbow, wrist, and fingers and posterior sensation of forearm and lateral dorsal hand option E= compression at upper trunk; loss of forearm flexion and supination and loss of sensation over lateral forearm option F= compression in Guyon canal; sensory deficits in ulnar-sided ring and small fingers; motor deficits= hyperextension of MCP joins and flexion of the distal and proximal interphalangeal joints when patient is asked to make a fist (ulnar claw)

23 years man -Decreased hearing, dizziness, and ringing in his right ear (6 months) -Exam: multiple soft, yellow plaques on his arms, chest, and back -Sensorineural hearing loss and weakness of facial muscles bilaterally -Gait is unsteady; MRI= 3-cm mass near the right internal auditory meatus and 2-cm mass at left cerebellopontine angle -Abnormal cells in these masses derived from? a)Neural tube b)Surface ectoderm c)Neural crest d)Notochord e)Mesoderm

answer: neural crest -Bilateral masses causing sensorineural hearing loss, tinnitus, and vertigo are acoustic neuromas, which arise from schwann cells of CN VIII -Compression of adjacent CN VII causes facial weakness -Combination of multiple cutaneous neurofibromas with bilateral acoustic neuromas is pathognomic for NF type 2 -Schwann cells are formed from neural crest cells, which arise from the lateral border of the neural plate (neuroectoderm) and migrate along somites to different parts of body -Other structures derived from neural crest cells= neurons of CN III-XII, peripheral nerve neurons (somatic and autonomic), skull bones, pia and arachnoid mater, odontoblasts, laryngeal cartilage, adrenal medulla, melanocytes, aorticopulmonary septum, and endocardial cushion -Immunohistochemical marker for neural crest cells is S-100, which is positive in melanomas, Langerhans cell histiocytosis, and schwannomas option A= gives rise to CNS glial cells (oligodendrocytes, astrocytes, ependymal cells) which are glial cells of CN I and II; optic gliomas which occur in NF type 1= derived from astrocytes; NF1 can present with similar cutaneous neurofibromas, but absence of café-au-lait spots on physical exam and acoustic neuromas= suggest NF type; NF2 is associated with optic nerve meningiomas rather than optic nerve gliomas option B= gives rise to anterior pituitary, external auditory canal, and inner ear structures as well as glands of the skin, parotid glands, ameloblasts/ Craniopharyngiomas arise from remnant of the Rathke's pouch, which is surface ectodermal derivative= present with childhood headache, bitemporal hemianopia, and/or symptoms of hyperprolactinemia option D= induces formation of neuroectoderm from primitive ectoderm; lateral border of neuroectoderm will give rise to embryologic precursor of Schwann cells; but notochord itself doesn't give rise to any neurological structure; it only forms nucleus pulposus option E= gives rise to bones, muscles (smooth, skeletal and cardiac), connective tissue (including serosal linings of body cavities), and dura mater, lymphatics, blood vessels, spleen, kidneys, adrenal cortex, and gonads

68 years man -30 mins after collapsing on street -Pulse and BP high -CT= intracerebral hemorrhage involving bilateral thalamic nuclei and 3rd ventricle -Stimuli unaffected? a)Facial fine touch b)Gustatory c)Visual d)Auditory e)Olfactory f)Proprioception

answer: olfactory -Olfactory nerve à Olfactory bulb (processes odor information) à primary olfactory cortex -Do not project directly to thalamus, the mediodorsal thalamic nucleus receives and sends information to the olfactory cortex -Damage to mediodorsal nucleus= does not impair cortical olfactory detection (would result in anosmia), but it impairs other olfactory functions (olfactory identification or discrimination (dysosmia) option A= conveyed by ventral posteromedial nucleus; relay center for CN V; receives afferent input from trigeminal nucleus and projects to primary somatosensory cortex option B= conveyed via ventral posteromedial nucleus; receives afferents from CN V; and projects to the primary somatosensory cortex option C= conveyed via lateral geniculate body, receives afferent from CN II via the superior colliculus and projects to the primary visual cortex option D= conveyed via medial geniculate body; receives afferents from inferior colliculus and superior olivary nucleus and projects to the primary auditory cortex option F= conveyed by the ventral posterolateral nucleus; afferent from gray matter of spinal cord via dorsal columns and projects to primary somatosensory cortex

57 years man -Exam: normal voluntary coughing but an impaired cough reflex -Nerve damaged at which site? a)Carotid sheath b)Infratemporal fossa c)Foramen magnum d)Aortic arch e)Piriform recess f)Parotid gland

answer: piriform recess -Cough reflex depends on afferent fibers of internal laryngeal nerve (branch of CN X), which transmit sensations of the larynx above the vocal cords, and on efferent fibers of the vagus, phrenic and spinal motor nerves -Able to cough normally (intact efferent pathway) but has impaired cough reflex (defect in afferent pathway) -Superior laryngeal nerve divides into internal and external branch beneath the internal carotid artery -the internal laryngeal nerve runs directly beneath the mucosa of the piriform recess, along with recurrent laryngeal nerve (can by injured by thyroidectomy or fishbone/food being trapped in the piriform fossa)= impaired cough reflex, increases risk for recurrent aspiration pneumonia option A= common carotid artery, parts of internal and external carotid, internal jugular veins, CN X, CN IX, part of recurrent laryngeal nerve= can lead to hoarseness and dyspnea but not laryngeal cough reflex mediated by internal laryngeal nerve option B= CN V3= mastication muscles option C= CN XI= trapezius and sternocleidomastoid= shoulder elevation and head turning contralaterally option D= left recurrent laryngeal nerve= hoarseness and dyspnea (paralysis of posterior cricoarytenoid muscle)= not responsible for cough reflex option F= CN VII; injured in parotid tumor surgeries

27 years man -Knife wound to his back -Exam: stab wound at level of T9; he withdraws the right foot to pain but is unable to sense vibration or whether his right toe is flexed or extended -Sensation in left leg is normal; 5/5 muscle strength in all extremities -Spinal column structure affected? a)dorsal root a)Posterior spinal artery b)Central spinal cord grey matter c)Lateral corticospinal tract d)Artery of Adamkiewicz

answer: posterior spinal artery -Unilateral loss of proprioception and vibration + preservation of motor function= isolated damage to dorsal column -Injury to right posterior spinal artery= posterior spinal artery syndrome (ischemia and subsequent infarction of posterior column, directly supplied by this artery) -Symptoms: absent ipsilateral proprioception and vibration sensation below level of wound -Normal motor function (corticospinal tract) and sensation to pain (spinothalamic tract) option A= complete loss of sensory function in corresponding T9 dermatome option C= causes: hyperextension injury, spinal cord compression, syringomyelia. Present with both sensory symptoms (e.g., loss pain/temperature sensation bilaterally) and motor symptoms (weakness). Most often in cervical region, involvement of upper extremities is more prominent option D= ipsilateral weakness below level of lesion option E= leads to anterior cord syndrome and can be accompanied by urinary and fecal incontinence from infarction of lumbosacral anterior spinal cord

65 years woman -Severe headache (2 hours ago) -Low temperature, high BP -Exam: cold skin; CT= subarachnoid hemorrhage -Damage to? a)Anterior cingulate gyrus b)Ventral lateral thalamic nucleus c)Pineal gland d)Preoptic nucleus e)Caudate nucleus

answer: preoptic nucleus -Preoptic nucleus in anterior hypothalamus= body's primary thermoregulator (damage= hypothermia or hyperthermia)= circulating pyrogens influence preoptic nucleus to increase thermoregulatory set point and initiate fever - afferent: thermoreceptor in skin -Efferent: organs involved in thermal regulation (e.g., heart, blood vessels) -Other regions involved in thermoregulation= 1) anterior hypothalamic nucleus (cooling response; vasodilation and sweating) 2) posterior hypothalamic nucleus (warming response; vasoconstriction, shivering) option A= modulation of emotional responses and autonomic activity (e.g., heart rate, blood pressure option B= coordination of movements option C= circadian rhythm, including the circadian variation in temperature (i.e., lower nocturnal core body temperatures option E= coordination of movement and higher cognitive function; damage= Huntington disease

34 years woman -Depressed mood, loss of interest and difficulty sleeping -Difficulty concentration -Physician prescribed escitalopram -Targets neurotransmitter produced by? a)Caudate nucleus b)Locus coeruleus c)Basal nucleus of Meynert d)Nucleus accumbens e)Raphe nucleus f)Substantia nigra

answer: raphe nucleus -Escitalopram is an SSRI used in treatment of major depressive disorder -Raphe nucleus= brainstem; primary site of serotonin production in CNS -Other conditions with low serotonin= anxiety disorders and Parkinson option A= innervated by dopaminergic neurons from substantia nigra pars compacta and would be affected by antidepressants with dopaminergic effects (e.g., bupropion) option B= pons; norepinephrine production; decreased levels= depression; SNRIs option C= acetylcholine; increased levels= parkinson; decreased levels= Alzheimer and Huntington option D= basal forebrain between caudate and putamen; major site of GABA synthesis; decreased GABA= anxiety and Huntington option F= pars compacta= dopamine production; decreased= Parkinson and depression; antidepressant (bupropion)

62 years man -Left-sided body weakness and involuntary urinary leakage -Exam: left-sided hemiparesis and decreased sensation -More prominent in the left lower extremity more than in left upper extremity -Vessel affected? a) right ACA b) left ACA c) right MCA d) left MCA e) right PCA f) left PCA g) basilar artery

answer: right ACA -Right ACA supplies right anteromedial cortex (including medial portion of frontal and parietal lobes) -ACA occlusion= loss of contralateral motor function and sensory (lower extremities); supplies medial frontal micturition center (responsible for bladder control) option B= opposite as A option C= a)right MCA; supplies right lateral cortex including temporal lobe and lateral portion of frontal and parietal lobes; can cause contralateral hemiparesis and hemisensory loss (but more likely upper extremities and face); also, horizontal gaze deviation, aphasia (dominant), or hemineglect (non-dominant) option D= opposite as C option E= right PCA; supplies right occipital cortex, posteromedial aspect of temporal lobe, and thalamus; occlusion= contralateral homonymous hemianopia with macular sparing; prosopagnosia, contralateral hemisensory loss option D= opposite of E, without prosopagnosia; but can cause alexia option G= basilar artery; supplies lower half of cerebellum, lower midbrain, lower pons, medulla, corticobulbar and corticospinal tracts; occlusion= vertigo, tinnitus, visual deficits, gait ataxia, and ipsilateral cranial nerve deficits with paresthesias and hemiplegia; rarely= locked-in syndrome

70 years woman -Total hip replacement surgery -Sagging of the left pelvis when her right leg is weight bearing -Nerve injured? a)Left superior gluteal nerve b)Right femoral nerve c)Right inferior gluteal nerve d)Left inferior gluteal nerve e)Left femoral nerve f)Right obturator nerve g)Right superior gluteal nerve h)Left obturator nerve

answer: right superior gluteal nerve -Exam shows positive Trendelenburg sign= caused by weakness of hip abductors (i.e., gluteus medius and minimus) -Damage to right superior gluteal nerve= lowering of left hip while standing on right foot (positive Trendelenburg sign) option A= right hip sagging option B and E= knee extension and hip/thigh flexion; sensory loss over anteromedial thigh and medial calf option C and D= gluteus maximus; thigh/hip extension option F and H= thigh adduction, external rotation; sensory loss in mid and lower thirds of medial thigh

56 years man -Excessive sleepiness history (sleeps 10-12 hours, and naps during day) -6 months ago= small cell lung carcinoma and underwent prophylactic cranial irradiation -Caused by damage to? a)Preoptic nucleus b)Ventromedial nucleus c)Suprachiasmatic nucleus d)Supraoptic nucleus e)Caudate nucleus f)Subthalamic nucleus

answer: suprachiasmatic nucleus -Suprachiasmatic nucleus= circadian rhythm -Afferent: retina -Decreased input= suprachiasmatic nucleus releases norepinephrine, which stimulates the release of sleep-inducing melatonin from pineal gland -Damage (i.e., radiation or metastasis)= hypersomnolence or sleep-wake disturbances option A= anterior hypothalamus; thermoregulation, release of GnRH (damage= changes in sexual behavior and erectile dysfunction and failure of thermoregulation) option B= stimulated by leptin, satiety; damage= very massive person option D= ADH synthesis; damage= central diabetes insipidus option E= damage= Huntington option F= damage= contralateral hemiballismus

66 years man -Undergoes coronary artery bypass grafting -Regained consciousness= can't see from either eye and can't move arms -Exam: bilaterally equal, reactive pupils -MRI= wedge-shaped cortical infarcts in both occipital lobes -Cause? a)Amyloid angiopathy b)Ruptured saccular aneurysm c)Lipohyalinosis d)Cardiac embolism e)Atherothrombosis f)Systemic hypotension

answer: systemic hypotension -Patient shows symmetrical infarcts in watershed regions of brain (occipitally at border of PCA and MCA causing his blindness) -Hypotension= decrease in perfusion to terminal areas of vascular fields (watershed areas)= most common cause of watershed infarct -Watershed-distribution strokes are more prevalent in patients following cardiac surgery due to global systemic hypoperfusion (especially, while on cardiopulmonary bypass) that occurs often during these surgeries option A= common cause of spontaneous intracranial hemorrhage in elderly patients; present with recurrent TIA-like symptoms and rapidly progressive dementia option B= common cause of subarachnoid hemorrhage, very severe headaches, nonreactive pupils, unconsciousness, rapidly worsening nausea, vomiting, and cardiovascular deterioration option C= lacunar strokes within the basal ganglia; most important predisposing factor= chronic hypertension; common risk factor for chronic hypertension= atherosclerosis option D= ischemic stroke, can affect watershed areas; but emboli often dislodge to small leptomeningeal arteries over watershed areas; won't block same vessels bilaterally option E= unilateral stroke like symptoms; can affect watershed areas but unilaterally

65 years man -Double vision -History: hypertension and Type 2 diabetes, smoker (40 years) -Exam: right eye abducted and depressed with slight intorsion -Left eye is normal; serum studies: HA1c= 11.5% -Additional findings? a)Inability to abduct the right eye b)Absent consensual light reaction on the right eye c)Loss of the right nasolabial fold d)Upper eyelid droop on the right eye e)Loss of smell f)Absent direct light reaction on the right eye

answer: upper eyelid droop on the right eye -Isolated CN III palsy= diabetic mononeuropathy (microangiopathic ischemia) -Ptosis (levator palpebrae superioris) -CN III palsy due to compression show dilated pupils, those with diabetic mononeuropathy normally DO NOT HAVE pupillary involvement because microangiopathy typically involves the vasa nervosum within the oculomotor nerve, while the pial blood vessels (which supply the superficial parasympathetic fibers) are usually spared= option F option A= CN VI option B= left eye is normal option C= CN VII option E= CN I

38 years woman -Surgery to remove papillary thyroid carcinoma -During surgery= structure lying directly adjacent to the superior thyroid artery at upper pole of thyroid lobe is damaged -Experiences? a)Voice pitch limitation b)Perioral paresthesias c)Ineffective cough d)Weakness of shoulder shrug e)Difficulty swallowing f)Shortness of breath

answer: voice pitch limitation -Damage to external branch of superior laryngeal nerve; which occurs in 30% of thyroid dissections -External branch of SLN innervates cricothyroid muscles, which is responsible for lengthening, thinning, and stiffening the vocal cords and increases the pitch of phonation -Cricothyroid= only tensor of vocal cord, denervation= inability to increase pitch of voice or produce explosive sounds as well as easy voice fatigability option B= can occur after thyroid surgery; result of hypocalcemia secondary to hypoparathyroidism; usually due to unintentional removal of one or several of the parathyroid glands; hypothyroidism is most frequent complication of total or near-total thyroidectomy; superior parathyroid glands are most commonly found inferior to superior thyroid artery and external branch of recurrent laryngeal nerve option C= unilateral recurrent laryngeal nerve injury. Causes the affected vocal fold to rest in paramedian to lateralized position, impairs tight glottic closure. Risk of injury during preparation of inferior pole of thyroid, it runs close to inferior thyroid artery option D= CN XI injury; in posterior triangle of neck (supplies trapezius and sternocleidomastoid). Common cause: biopsy of cervical lymph nodes option E= and increased risk of aspiration= bilateral injury to recurrent laryngeal nerve (innervates all intrinsic muscles of larynx except cricothyroid). Also, carries sensory input from the larynx below the vocal cords option F= bilateral injury to recurrent laryngeal nerve. RLN innervates posterior cricoarytenoids, responsible for vocal cord abduction; bilateral injury= vocal cords can't abduct= restrict air entry into trachea

65 years man -Suspected stroke; history: chronic hypertension -Right-handed; CT= acute cerebral infarction in the left posterior limb of internal capsule -Findings? a)Weakness of the right leg b)Hemineglect of the right side c)Hemiballismus of the left side d)Paralysis of the left face e)Loss of sensation of the left arm f)Hemianopia of the right visual field

answer: weakness of the right leg -Lacunar infarct of the posterior limb of the left internal capsule -Contains anterior and lateral corticospinal tracts, thalamocortical tract -Pure motor stroke= most common= contralateral hemiparesis (weakness of right leg) -Chronic hypertension= risk factor for microatheroma formation and lipohyalinosis in poorly-collateralized small penetrating arteries of brain (e.g., lenticulostriate arteries)= lacunar stroke option B= left-handed person= infarction in right parietal cortex option C= lacunar stroke in right subthalamic nucleus option D= damage to corticobulbar tracts in internal capsule that supply facial motor nuclei; but here would affect right face option E= right internal capsule stroke option F= left optic tract, optic radiation or visual cortex