Chapter 2: Head

Which of the basal ganglia is most lateral? Select one: a. Putamen. b. Globus pallidus. c. Claustrum. d. All three options are all on the same sagittal plane.

c.

One of four masses of gray matter located deep in the cerebrum:

Basal ganglia

Parts of the forebrain:

Cerebrum and diencephalon

Arterial anastomosis:

Circle of Willis

Portion of the brain composed of white matter connecting the two hemisphere of the cerebrum:

Corpus callosum

Basal ganglia composed of caudate and lentiform nucleus:

Corpus striatum

Cerebral abscess

Definition - collection of pus, immune cells, and other material in the brain, usually from a bacterial or fungal infection. •Causes - occur when bacteria or fungi infect part of the brain. The source of the infection is often not found. However, the most common source is a lung infection. Less often, a heart infection is the cause. Germs may also travel from a nearby infected area (for example, an ear infection or a tooth abscess) or enter the body during an injury (such as a gun or knife wound) or neurosurgery. Swelling and irritation (inflammation) develop in response to this infection. Infected brain cells, white blood cells, live and dead bacteria, and fungi collect in an area of the brain. Tissue forms around this area and creates a mass. •Symptoms -Symptoms may develop slowly, over a period of 2 weeks, or they may develop suddenly: Changes in mental status (confusion, decreasing responsiveness, drowsiness, eventual coma, inattention,irritability, slow thought processes); Decreased movement; Decreased sensation; Decreased speech (aphasia); Fever and chills; Headache; Language difficulties; Loss of coordination; Loss of muscle function, typically on one side; Seizures; Stiff neck; Vision changes; Vomiting Testing - Blood cultures, Chest x‐ray, Complete blood count (CBC), Head CT scan, Electroencephalogram (EEG), MRI of head, Testing for the presence of antibodies to organisms such as Toxoplasma gondii and Taenia solium. A needle biopsy is usually performed to identify the cause of the infection. CT ‐ After the injection of a contrast material, CT scans characteristically show the brain abscess as a hypodense center with a peripheral uniform enhancement ring. Rarely, a well‐ organized abscess wall fails to generate such ring enhancement. In the earlier cerebritis 216 stages, CT scans show nodular enhancement with areas of low attenuation without enhancement. As the abscess forms, contrast enhancement is observed. After encapsulation, the contrast material cannot help differentiate the clear center and the CT scan is similar in appearance to those obtained during the early cerebritis stage. MRI ‐Many authorities consider MRI to be the first diagnostic method in the diagnosis of brain abscess. It allows for accurate diagnosis and excellent follow‐up of the lesions because of its superior sensitivity and specificity. Compared with CT scanning, MRI offers a better ability to detect cerebritis, greater contrast between cerebral edema and the brain, and earlier detection of satellite lesions and the spread of inflammation into the ventricles and subarachnoid space. *Contrast enhancement with gadolinium helps differentiate the abscess, the enhancement ring, and the cerebral edema around the abscess. T1‐weighted images enhance the abscess capsule, and T2‐weighted images can demonstrate the edema zone around the abscess. *Diffusion‐weighted (magnetic resonance) imaging (DWI) can be used to differentiate between ring‐enhancing lesions caused by brain abscess (hypertensive on DWI) from a malignant lesion (hypotensive on DWI). •Treatment - A brain abscess is a medical emergency. Pressure inside the skull may become high enough to be life threatening. Antiobiotics, anti‐fungal medications, and surgery are treatment options depending on severity and number of abscess(es). Prognosis - If untreated, a brain abscess is almost always deadly. With treatment, the death rate is about 10 ‐ 30%. The earlier treatment is received, the better. Some patients may have long‐term neurological problems after surgery.

Multiple Sclerosis

Description - characterized by multiple inflammatory plaques of demyelination involving the white matter tracts; progressive disease; also characterized by destruction the myelin sheath (lipid and protein layer that insulates the nerve cell); areas of demyelination are called plaques; goes through periods of exacerbation and remission Etiology - unknown; theories suggest a slow acting viral infection and an autoimmune response; other theories suggest environmental and genetic factors Epidemiology - females slightly more affected 3:2 ratio; incidence between 18‐50 years old; most common in people of European descent and less common is Asians and rarely black Africans Signs and symptoms - paresthesia (abnormal sensations in extremities or one side of the face), numbness, tingling, "pins and needles" feeling, muscle weakness, vertigo, visual disturbances, extreme emotional changes, ataxia, abnormal reflexes, dysuria Imaging characteristics - MRI is the modality of choice MRI imaging - T1 isointense to hypointense; PD hyperintense; T2 hyperintense; active plaques show contrast enhancement Treatment - no specific treatment; corticosteroids and other drugs used to treat symptoms; physical therapy might postpone or prevent certain disabilities Prognosis - varied and unpredictable

Pituitary adenoma

Description - classified as functioning or nonfunctioning based on whether or not they secrete hormones Etiology - unkown; however predisposition that the tumors are inherited through an autosomal dominant trait Epidemiology - 10% of all intracranial neoplasms; affect males and females equally in 20's and 30's Signs and symptoms - frontal headaches, visual symptoms, ICP, personality changes, seizures, rhinorrhea, and pituitary apoplexy secondary to hemorrhagic infarction Imaging characteristics - less than 10 mm = microadenoma; greater than 10 mm = macroadenoma Prognosis - fair to good depending how much it has spread outside of the sella turcica

Subdural hematoma

Description - collection of venous blood between dura mater and arachnoid membrane (subdural space); usually results from the head hitting an immovable object but not usually associated with a skull fracture Etiology - head striking an immovable object; high speed acceleration or deceleration related head injury - results in tearing of the veins between cerebral cortext and dural veins; can also result from birth trauma or child abuse Epidemiology - people with blunt trauma to the head but symptoms not always noticeable right away; three time intervals between trauma and onset of symptoms - (1) acute - 24‐ 48 hours after injury, (2) subacute - between 48 hours and 2 weeks, (3) chronic - 7‐10 days Signs and symptoms - headaches, change in mental status, motor and sensory deficits, increased ICP, possible deterioration of neurologic status Imaging characteristics - CT preferred for acute diagnosis and MRI preferred in subacute and chronic stages; crescent shaped, conforming to the contour of the cranium; may extend into interhemispheric or tentorial subdural space Treatment - drained through a burr hole or craniotomy Prognosis - mortality rate for acute greater than 50% and chronic less than 10%; most patients resume preoperative functional status; outcome dependent on presurgical neurologic status

(Arnold) Chiari malformations

Description - consists of a wide variety of congenital anomalies affecting the hindbrain; characterized by downward elongation of brainstem (medulla oblongata), cerebellum (cerebellar tonsils -controls balance and coordination), and fourth ventricle into the cervical spinal cord; three types Etiology - several theories; one that is generally accepted is that they posterior fossa is too small causing a herniation of the brain stem and cerebellar tonsils through the foramen magnum Epidemiology - type I are found more often in adults, usually incidentally, than in children; no gender preference Signs and symptoms - hydrocephalus and developmental defects can be seen early on in infants; young adults can be asymptomatic until neurologic deficits occur Imaging characteristics - MRI is modality of choice Treatment - surgical intervention used to decompress the posterior fossa; shunt placement used to treat hydrocephalus Prognosis - depends on type, age at diagnosis, and extent of other related developmental defects; prognosis for infants is worse than for adults

Hydrocephalus

Description - enlargement of the ventricular system; water on the brain; can result from excessive amount of CSF production, inadequate reabsorption of CSF, or obstruction of the flow of CSF from one or more ventricles; two types - communicating and noncommunicating Noncommunicating - flow of CSF is obstructed by a mass, congenital narrowing of the aqueduct of Sylvius, or associated with a meningomyelocele Communicating - results from an overproduction of CSF in the choroid plexus or inadequate reabsorption of CSF by arachnoid villi Etiology - see description for causes of hydrocephalus Epidemiology - congenital defect might be associated with a history of a meningomyelocele Signs and symptoms - increase in head circumference, behavioral changes like irritability and lethargy, seizures, vomiting, change in appetite Imaging characteristics - MRI better for evaluation Treatment - shunting excess CSF into right atrium or peritoneal cavity Prognosis - good after shunting

(Intracranial) Aneurysm

Description - localized dilatation of a cerebral artery; most common form is the berry aneurysm, a saclike outpouching usually at an arterial junction in the COW; often rupture and result in SAH Etiology - weakening of the arterial wall; hypertension and atherosclerosis will restrict blood flow which increases blood pressure on an arterial wall stretching it like a balloon; increased incidence with PCKD, aortic coarctation, and family history Epidemiology - slightly higher in women than men; peak age is 40‐60 years; anterior circulation affected 90% of the time and vertebrobasilar circulation affected only 10% Signs and symptoms - can go undetected until rupture; large nonruptured aneurysm can mimic signs and symptoms of a tumor - vary depending on location and severity; other common S&S are headahces, nausea, vomiting, hemiparesis or motor deficit, nuchal rigidity, LOC, and coma Imaging characteristics - conventional angiography is the gold standard to diagnose Treatment - surgical intervention with a small metal clip or ligation around the neck of the aneurysm; neuroradiologic intervention techniques include Guglielmi detachable coils Prognosis - once it ruptures, depends on severity of initial hemorrhage, rebleeding of aneurysm, and vasospasm

Epidural hematoma

Description - mass of blood from trauma to the head; most are arterial in origin located between the skull and dura mater in temporoparietal region; usually associated with a linear skull fracture that tears the middle meningeal artery; venous EDH's are less common but typically occur in the posterior fossa or adjacent to occipital lobes of cerebrum Etiology - blunt trauma with a tearing of middle meningeal artery Epidemiology - those who are likely to experience blunt head trauma Signs and symptoms - loss of consciousness, hemiparesis, headaches, dilated pupils, increased ICP, nausea, vomiting, dizziness, convulsions, and decerebrate ridigity Imaging characteristics - biconvex in shape, displacing the brain away from the skull CT imaging - underlying fracture, acute stage - hyperdense; subacute stage - isodense; chronic stage ‐ hypodense MRI imaging - subacute stage - hyperintense on T1 and T2; acute stage - isointense on T1 and hypointense on T2 Treatment - surgical emergency to remove blood Prognosis - due to irreversible brain damage, mortality rates are high even with early diagnosis and treatment; without complications, normal recovery is possible; large EDH's may result in neurologic deficit

Glioblastoma

Description: rapidly growing, highly malignant tumor usually found in intercerebral hemispheres but might develop in the brainstem, cerebellum, or spinal cord. It spreads by direct extension, crossing through connecting white matter tracts like the corpus callosum. Etiology- Unknown Epidemiology - most common primary intracranial tumor; appears between 45 and 60 years old; males slightly more affected Signs and symptoms - nausea, vomiting, headaches, papilledema, change in mental status, seizures, speech and sensory disturbances Imaging characteristics - appear heterogeneous with edema and mass effect Treatment - surgical resection if possible, radiation therapy, and chemotherapy Prognosis - poor; 1 and 2‐year survival rates are 50% and 15%

Spongy bone found between two layers of compact bone in skull:

Diploe

Convolution:

Gyrus

Central lobe of the cerebrum:

Insula

The anterior cerebellar notch accommodates the Select one: a. Third ventricle. b. Fourth ventricle. c. Pituitary gland. d. Pineal gland. e. Falx cerebelli.

b.

Parts of the midbrain:

Peduncles and tectum

Parts of the hindbrain:

Pons, medulla oblongata, and cerebellum

Sheet of nervous tissue separating the two lateral ventricles:

Septum pellucidum

The vertebral arteries joint together to form the Select one: a. Posterior communicating artery. b. Posterior cerebral artery. c. Common carotid artery. d. Basilar artery.

d.

On axial images, the dip of the meningeal layer of the dura mater between the two hemispheres of the cerebellum is identified as the Select one: a. Falx cerebri. b. Falx cerebelli. c. Tentorium cerebelli. d. Diaphragma sella.

b.

Pineal gland tumors

The pineal gland develops during the second month of gestation as a diverticulum in the diencephalic roof of the third ventricle. Pineal region tumors are derived from cells located in and around the pineal gland. •Pineal region tumors make up 0.4‐1.0% of intracranial tumors in adults and 3.0‐8.0% of brain tumors in children. Most children are aged 10‐20 years at presentation, with the average age being 13 years. Adults typically are older than 30. •Symptoms ‐ headache, nausea, and vomiting caused by aqueductal compression and resultant obstructive hydrocephalus. Untreated, hydrocephalus may lead progressively to lethargy, obtundation, and death. •High‐resolution MRI with gadolinium is necessary in the evaluation of pineal region lesions. Tumor characteristics, such as size, vascularity, and homogeneity, can be assessed, as well as the anatomic relationship with surrounding structures. Irregular tumor borders can be suggestive of tumor invasiveness and associated histologic malignancy. Although the type of tumor cannot be determined reliably from the radiographic characteristics alone, some patterns are associated with specific tumors. •Treatment ‐ Benign cysts of the pineal gland are diagnosed more frequently with the increased use of MRI for standard workups unrelated to the pineal region. These incidental lesions appear radiographically as cystic structures with peripheral calcification and rimlike contrast enhancement. They are normal variants of pineal gland anatomy, and, once documented, they require no treatment unless they grow. Otherwise, surgery. •Prognosis ‐ Excellent because of the radiosensitivity of these tumors.

Bridge connecting the right and left cerebellar hemispheres:

Vermis

Interventricular foramen is a synonym for Select one: a. Foramen of Monro b. Foramen of Magendie. c. Foramen of Luschka. d. Cerebral aqueduct.

a.

On an axial image, the colliculi are seen anterior to the quadrigeminal cistern and posterior to the Select one: a. Peduncles. b. Anterior cerebellar notch. c. Pineal gland. d. Fourth ventricle.

a.

On axial images, the dip of the meningeal layer of the dura mater in the longitudinal fissure is identified as the Select one: a. Falx cerebri. b. Falx cerebelli. c. Tentorium cerebelli. d. Diaphragma sella.

a.

The anterior section of the corpus callosum is the Select one: a. Genu. b. Body. c. Splenium. d. The corpus callosum does not have names for its various sections.

a.

The dura mater proper Select one: a. Is the inner meningeal layer of the dura mater. b. Is the outer layer of the dura mater. c. Is the layer of the dura mater acting as the inner periosteum of the cranium. d. Acts as the periosteal lining of the vertebral canal below the foramen magnum.

a.

The fissure seen on sectional images separating the two hemispheres of the cerebrum is the Select one: a. Longitudinal. b. Sylvian. c. Transverse. d. Central. e. Lateral.

a.

The foramen of Monro or interventricular foramen connects the Select one: a. Lateral ventricles with the third ventricle. b. Fourth ventricle with the spinal cord. c. Third ventricle with the fourth ventricle. d. Fourth ventricle with the meningeal space.

a.

The fourth ventricle is at the level of the Select one: a. Petrous portion of the temporal bone. b. Midbrain. c. Corpus callosum. d. Collateral trigone.

a.

The meningeal layer in contact with the cranium is the Select one: a. Dura mater. b. Arachnoid. c. Pia mater. d. None of the choices.

a.

The midline space between the two lateral ventricles is the Select one: a. Septum pellucidum. b. Genu. c. Splenium. d. Fornix.

a.

The neurons bringing in sensory information to the central nervous system are Select one: a. Afferent neurons. b. Efferent neurons. c. Motor neurons. d. Afferent and motor neurons. e. Efferent and motor neurons.

a.

White brain matter Select one: a. Is composed of neurons with myelinated axons. b. Is found in the cortex of the brain. c. Is composed of neurons with no axons or dendrites. d. Is the matter making up the basal ganglia.

a.

An afferent neuron Select one: a. Is a sensory neuron and has multiple dendrites. b. Is a sensory neuron and has a single dendrite. c. Is a motor neuron and has a single dendrite. d. Is a motor neuron and has multiple dendrites.

b.

How can you differentiate between gray matter axons and white matter axons? Select one: a. Gray matter axons are myelinated. b. Gray matter axons are unmyelinated. c. White matter axons are myelinated. d. White matter axons are unmyelinated

b.

The foramen of Magendie connects the Select one: a. Lateral ventricles with the third ventricle. b. Fourth ventricle with the spinal cord. c. Third ventricle with the fourth ventricle. d. Fourth ventricle with the meningeal space.

b.

The pituitary gland Select one: a. Is inferior to the splenium. b. Is the "master gland" of the body. c. Is an endocrine gland, but it does not actually manufacture any hormones. d. None of the choices. e. All of the choices.

b.

What is the area of the brain called that is responsible for the right half of the brain controlling the left half of the body and vice versa? Select one: a. Olive. b. Decussation of the pyramids of medulla. c. Diaphragm sella. d. Collateral trigone.

b.

Which is not a synonym for the other terms? Select one: a. Tectum. b. Colliculus. c. Quadrigeminal plate. d. Corporal quadrigemina.

b.

Which is not considered part of the hindbrain? Select one: a. Pons. b. Quadrigeminal plate. c. Cerebellum. d. Medulla oblongata. e. All of the choices are part of the hindbrain.

b.

At what level do the common carotids bifurcate into the internal and external carotid arteries? Select one: a. C1-C2. b. C2-C3. c. C3-C4. d. C4-C5

c.

The amygdaloid nucleus is associated with the Select one: a. Putamen. b. Globus pallidus. c. Caudate nucleus. d. Claustrum.

c.

The cerebral aqueduct connects the Select one: a. Lateral ventricles with the third ventricle. b. Fourth ventricle with the spinal cord. c. Third ventricle with the fourth ventricle. d. Fourth ventricle with the subarachnoid space.

c.

The choroid plexus originates in the Select one: a. Dura mater. b. Arachnoid. c. Pia mater. d. None of the choices.

c.

The circle of Willis Select one: a. Provides an alternate source of blood should a vessel involved be compromised. b. Equalizes blood pressure. c. Both of the options. d. Neither of the options.

c.

The connecting tissue of the two hemispheres of the cerebrum is the Select one: a. Corpus striatum. b. Centrum semiovale. c. Corpus callosum. d. Vermis.

c.

The dural sinuses are found Select one: a. Between the dura mater and arachnoid. b. Between the arachnoid and pia mater. c. Between the endosteal layer and inner meningeal layer of the dura mater. d. None of the choices.

c.

The fissure separating the cerebrum from the cerebellum is the Select one: a. Longitudinal. b. Sylvian. c. Transverse. d. Central. e. Lateral.

c.

The structures of the inner ear are being protected by what? Select one: a. Tympanic portion of the temporal bone. b. Squamous portion of the temporal bone. c. Petrous portion of the temporal bone. d. Mastoid portion of the temporal bone.

c.

Which basal ganglion is C-shaped and conforms to the shape of the lateral ventricles? Select one: a. Putamen. b. Globus pallidus. c. Caudate nucleus. d. Claustrum.

c.

Which is not composed of gray matter? Select one: a. Basal ganglia. b. Cortex of the cerebrum. c. Centrum semiovale. d. None of the choices. e. All of the choices.

c.

Which part of the brain forms the floor of the third ventricle and also communicates with the pituitary gland via its attachment by the infundibulum? Select one: a. Epithalamus. b. Thalamus. c. Hypothalamus. d. Metathalamus.

c.

What are the significant brain activities or centers in the vicinity of the medulla oblongata? Please select all that apply. Select one or more: a. Speech center. b. Auditory center. c. Vasomotor center. d. Cardiac center. e. Balance center. f. Respiratory center.

c., d., f.

Cisterns Select one: a. Are pooling areas for cerebrospinal fluid. b. Generally are named by location. c. Area a widening of the subarachnoid space. d. All of the choices.

d.

The collateral trigone is a triangular area found in the area where which two parts of the lateral ventricles unite? Select one: a. Anterior (frontal) horn and body. b. Anterior (frontal) horn and posterior (occipital) horn. c. Anterior (frontal) horn and temporal horn. d. Posterior (occipital) horn and temporal horn.

d.

The endosteal layer of the dura mater Select one: a. Is the outer layer of the dura mater. b. Is the layer of the dura mater acting as the inner periosteum of the cranium. c. Is the periosteal lining of the vertebral canal below the foramen magnum. d. is all of the choices.

d.

The fissure separating the frontal lobe of the cerebrum from the parietal lobes is the Select one: a. Longitudinal. b. Sylvian. c. Transverse. d. Central. e. Lateral.

d.

The foramina of Luschka connect the Select one: a. Lateral ventricles with the third ventricle. b. Fourth ventricle with the spinal cord. c. Third ventricle with the fourth ventricle. d. Fourth ventricle with the meningeal space.

d.

The fornix Select one: a. Is composed of gray matter. b. Forms the floor of the lateral ventricles. c. Is best seen on axial CT images. d. All of the choices. e. None of the choices.

d.

The hypothalamus Select one: a. Is inferior to the thalamus. b. Forms the anterior wall of the third ventricle. c. Communicates with the pituitary gland via the infundibulum. d. All of the choices.

d.

The intermediate mass Select one: a. Is a point of communication for the thalamus. b. Passes through the third ventricle. c. Is composed of gray matter. d. All of the choices

d.

The number of cranial nerves arising from the brainstem is Select one: a. 0. b. 6. c. 8. d. 10. e. 12.

d.

The optic nerve passing through the optic chiasma terminate in the Select one: a. Midbrain. b. Cerebellum. c. Pons. d. Thalamus.

d.

The pons Select one: a. Is superior to the medulla. b. By definition means "tissue connecting two or more parts." c. Is anterior to the cerebellum. d. All of the choices.

d.

Where would you find diploe? Select one: a. Surrounding the choroid plexus. b. In the basal ganglia. c. In the centrum semiovale. d. Between the layers of compact bone in the skull. e. In the cortex of the cerebrum.

d.

Which part of the brain serves as a message station between other areas of the brain? Its name means "tissue connecting two or more parts." Select one: a. Medulla oblongata. b. Peduncles. c. Tectum. d. Pons.

d.

A significant brain activity or center in the vicinity of the medulla oblongata is the Select one: a. Vasomotor center. b. Cardiac center. c. Respiratory center. d. Crossing of nerve pathways. e. All of the choices.

e.

The infundibulum Select one: a. Connects the hypothalamus and thalamus. b. Connects the hypothalamus and pituitary gland. c. Passes through the diaphragma sella. d. Connects the hypothalamus and thalamus & passes through the diaphragm sella. e. Connects the hypothalamus and pituitary gland & passes through the diaphragm sella.

e.

The lateral or Sylvian fissure is external to the Select one: a. Frontal lobe. b. Temporal lobe. c. Parietal lobe. d. Occipital lobe. e. Insula.

e.

Where in the brain is the decussation of the pyramids? Select one: a. Midbrain. b. Pons. c. Cerebellum. d. Cerebrum. e. Medulla.

e.

Quadrigeminal plate:

tectum