[5304] Week 2- STROKE

Which of the following is the MOST accurate and precise statement regarding the blood supply to the vestibular system? a. its supplied by the basilar artery b. its supplied by the labyrinthine artery which is typically a branch of the vertebral arteries c. its supplied by the labyrinthine artery which is typically a branch of AICA d. its supplied by the posterior vestibular artery which is typically a branch of the vertebral arteries

** c. its supplied by the labyrinthine artery which is typically a branch of AICA

In a patient with a lateral medullary stroke (Wallenburg syndrome), which of the following is correct? a. the artery that is usually involved is the posterior inferior cerebellar artery (PICA) b. the patient should not have a hypoglossal nerve (CN XII) lesion c. the patient may have a lesion of the inferior olivary nucleus d. A, B and C are correct

**d. A, B and C are correct

CLASSIFICATION OF ISCHEMIC EVENTS - TIAs

-Amaurosis fugax (Latin fugax meaning fleeting, Greek amaurosis meaning darkening, dark, or obscure). A painless transient monocular visual loss Due to decreased perfusion through ophthalmic artery (for our purposes), terminal branch of internal carotid artery. May be: -Embolic -Hemodynamic -Ocular -Neurologic -Idiopathic

Branches of the Vertebral Artery #2: Anterior Spinal Artery

2. Anterior Spinal Artery -Formed from a Y- shaped union of a branchfrom each vertebral artery -Runs down the ventral median fissure the length of the cord. Distribution: a. supplies the ventral 2/3 of the spinal cord.

Interactive Metronome (IM) Training Goals #2

2. Build more efficient & synchronized connections between neural networks

Blood supply to the PONS #2: Labyrynthine arteries

2. Labyrynthine arteries, may branch from the basilar, but variable in its origin. Supplies the region of the inner ear. Divides into two branches; a. anterior vestibular b. common cochlear The labyrinthine has a variable origin, according to a study done by Wende et. al., 1975, (sample size of 238) the artery originated from; 1. Basilar (16%) 2. AICA (45%) 3. Superior cerebellar (25%) 4. PICA (5%) 5. Remaining 9% were of duplicate origin

CLINICAL PRESENTATION #2

2. Middle Cerebral Artery occlusion: a. Most occlusions in the first portion of this artery are due to emboli and typically produce a neurological deficit. b. Opportunity for collateral circulation is restricted to anastomotic blood flow from the anterior and posterior cerebral arteries on the surface of the brain. c. Neurological symptoms: -hemiplegia -hemisensory deficit -hemianopsia -aphasia (if infarct is in the dominant hemisphere)

Branches of the Basilar Artery #2

2. Pontine arteries: Numerous smaller branches that can be subdivided into Paramedian and Circumferential pontine arteries. The Circumferential can be further subdivided into Long and Short pontine arteries. Distribution: a. paramedian pontine - basal pons b. circumferential pontine - lateral pons and middle cerebellar peduncle, floorof fourth ventricle and pontine tegmentum

CLASSIFICATION OF ISCHEMIC EVENTS #2

2. Reversible Ischemic Neurological Deficit (RIND) Less used - less useful A focal brain ischemia in which the deficit improves over 72 hours - 6 weeks. Deficits may not completely resolve in all cases.

Blood Supply to the PONS #2

2. Superior Cerebellar arteries, originates near the end of the Basilar artery, close to the Pons-Midbrain junction. Runs along dorsal surface of cerebellum Distribution: a. cerebellar cortex, white matter and central nuclei b. pontine tegmentum, superior cerebellar peduncle and inferior colliculus

Superior Saggital Sinus drains into the

Great cerebral vein of Galen

The paramedian branches of the Basilar artery supplies the paramedian regions of the _______?

Pons this includes corticospinal fibers (basis pedunculi), the medial leminiscus, abducens nerve and nucleus (cranial nerve VI) , pontine reticular area, and periaquaductal gray areas

CVA syndromes: Posterior Cerebral Artery

Posterior Cerebral Artery -Alexia without Agraphia Anatomy Cerebral hemisphere: Left occipital region plus splenium of corpus collosum. Signs & Symptoms -Alexia - Splenium of corpus collosum -Contralateral Visual loss - homonymous hemianopia. Left occipital region. -Pure word blindness. Can write but not read. Balint Syndrome Anatomy -Cerebral hemisphere: Bilateral parietal-occipital lobes -Vascular - Posterior cerebral artery: Bilateral Signs & Symptoms Bilateral Loss of voluntary but not reflex eye movements Optic ataxia - poor visual-motor coordination Asimultagnosia - inability to understand visual objects.

CVA syndromes: Claude Syndrome

Posterior Cerebral Artery -Claude Syndrome Anatomy - Midbrain: Tegmentum Signs & Symptoms Contralateral -Ataxia - arm and leg -Oculomotor palsy with contralateral tremor and ataxia.

CVA syndromes: Weber Syndrome

Posterior Cerebral Artery Weber Syndrome Anatomy - Midbrain: Base. Vascular - Penetrating branches to midbrain. Signs & Symptoms - Contralateral Weakness - upper and lower extremity. Corticospinal tract Occulomotor Nerve (CN III) Palsy. Paramedian midbrain syndrome (Benedikt syndrome), is a rare presentation characterized by the presence ofan oculomotor nerve (CN III) palsy andcerebellar ataxia including tremor. -structures affected include CN III nucleus, Rednucleus, corticospinal tracts, brachium conjunctivum, and the superior cerebellar peduncle decussation. -It is very similar in etiology, morphology and clinical presentation to Weber syndrome; the main difference between the two being that Weber is more associated with hemiplegia (i.e. paralysis), and Benedikt with hemiataxia (i.e. disturbed coordination).

Wallenberg Syndrome

Posterior Inferior Cerebellar Artery Lateral Medullary Syndrome (Wallenberg Syndrome) Vascular - Vertebral artery: Distal branches; Superior lateral medullary artery; Posterior inferior cerebellar artery: Less common than vertebral.

Blood Supply to the Spinal Cord and Brain Stem

The brain is one of the most metabolically active organsin the body, receiving 17% ofthe total cardiac output andabout 20% of the oxygen available in the body. The brain receives it's blood fromtwo pairs of arteries, the carotid andvertebral. About 80% of the brain'sblood supply comes from the carotid, and the remaining 20% from the vertebral.

Arterial Supply

Spinal Arteries Anterior (1) & Posterior (2) from Spinal Artery Radicular ----- Segmental arteries from Vertebral, Ascending Cervical, Lumbar Artery

More statistics on Cerebrovascular Disease

Stroke is a leading cause of serious long-term disability, with an estimated 5.4 million stroke survivors currently alive today. • The American Heart Association estimates that stroke cost about $70-180 billion in both direct and indirect costs in the United States alone. • Stroke costs the United States an estimated $33 billion each year. This total includes the cost of health care services, medicines to treat stroke, and missed days of work. Stroke is a leading cause of serious long-term disability. • Every year, an estimated 30,000+ people in the United States experience a ruptured cerebral aneurysm and as many as 6% may have an unruptured aneurysm. • Arteriovenous malformations (AVMs) are present in about 1% of the general population. The risk of hemorrhage from an AVM is 4% per year with a 15% chance of stroke or death with each hemorrhage.

LOCKED-IN-SYNDROME: other clinical points

Substantial infarcts within the Pons are generally rapidly fatal, due to failure of central control of respiration Infarcts within the ventral portion of the Pons can produce paralysis of all movements except the eyes. Patient is conscious but can communicate only with eyes... only motor function is eyes

TIA symptoms include:

Sudden numbness or weakness of the face, arm or leg, especially on one side of the body. Sudden confusion, trouble speaking or understanding. Sudden trouble seeing in one or both eyes. Sudden trouble walking, dizziness, loss of balance or coordination. Sudden, severe headache with no known cause.

Blood supply to the BRAIN STEM

The brain stem (medulla, pons, midbrain) receives the bulk of its blood supply from the vertebrobasilar system. Except for the labyrynthine branch, all other branches supply the brain stem and cerebellum The posterior cerebral has only a small contribution, its main target being the posterior cerebral hemispheres

Blood supply to the MEDULLA

The Medulla is supplied by the: 1. Anterior spinal artery, sends blood to the paramedian region of the caudal medulla. 2. Posterior spinal artery, supplies rostral areas, including the gracile and cuneate fasiculi and nuclei, along with dorsal areas of the inferior cerebellar peduncle. 3. Vertebral artery, bulbar branches supply areas of both the caudal and rostral medulla. 4. Posterior inferior cerebellar artery, supplies lateral medullary areas.

Blood Supply to the PONS

The Pons is supplied by the: 1. The Basilar artery, contributions of this main artery can be further subdivided; a. paramedian branches, to medial pontine region b. short circumferential branches, supply anterolateral pons c. long circumferential branches, run laterally over the anteriorsurface of the Pons to anastomose with branches of the anterior inferior cerebellar artery (AICA). 2. Some reinforcing contributions by the anterior inferior cerebellar andsuperior cerebellar arteries

What travels through the cavernous sinus?

CN III, IV, VI, ICA, V1, V2, and sympathetic nerves

Occlusion of the anterior spinal artery may lead to the cord syndrome, characterized by:

CORD SYNDROME (anterior spinal artery): 1. Loss of ipsilateral motor function, due to damage to ventral gray matter and the ventral corticospinal tract. 2. Loss of contralateral pain and temperature sensation, due to damage to the spinothalamic pathway [Occlusion: the blockage or closing of a blood vessel or hollow organ]

Blood supply to the MIDBRAIN

The major blood supply to the midbrain is derived from branches of the basilar artery: 1. Posterior cerebral artery, forms a plexus with the posterior communicating arteries in the interpeduncular fossa, branches from this plexus supply a wide area if the midbrain 2. Superior cerebellar artery, supplies dorsal areas around the central gray and inferior colliculus with support from branches of the posterior cerebral artery. 3. Quadrigeminal, (some posterior choroidal) a branch of the posterior cerebral, provides support for the tectum (superior and inferior colliculi) 4. Posterior communicating artery, derived from the internal carotid, joins the posterior cerebral to form portions of the circle of Willis (arterial circle). Contributes to the interpeduncular plexus 5. Branches of these arteries are best understood when grouped intoparamedian, short circumferential and long circumferential

blood supply to the MIDBRAIN

The posterior choroidal arteries originate near the basilar bifurcation into the posterior cerebral arteries. In addition to providing reinforcement to the midbrain short and long circumferential arteries they move forward to supply portions of the diencephalon and the choroid plexus of the third and lateral ventricles

Occlusion of the posterior inferior cerebellar artery (or contributing vertebral) will produce a characterized by: (lateral medullary syndrome or Wallenberg's syndrome)

WALLENBERG'S SYNDROME 1. A contralateral loss of pain and temperature sense, due to damage to the anterolateral system (spinothalamic tract) 2. An ipsilateral loss of pain and temperature sense on the face, due to damage to the spinal trigeminal nucleus and tract 3. Vertigo, nausea and vomiting, due to damage to the vestibular nuclei 4. Horner's syndrome, (miosis [contraction of the pupil], ptosis [sinking of the eyelid], decreased sweating), due to damage to the descending hypothalamolspinal tract

Occlusion of midbrain paramedian branches produces a medial midbrain or superior alternating hemiplegia (or Weber's syndrome) characterized by:

WEBER'S SYNDROME [superior alternating hemiplegia] 1. Contralateral hemiplegia of the limbs, and contralateral face and tongue due to damage to the descending motor tracts(crus cerebri). 2. Ipsilateral deficits in eye motor activity, caused by damage to the oculomotor nerve (III)

blood supply to the MIDBRAIN: The short circumferential arteries originate from the interpeduncular plexus and portions of the posterior cerebral and superior cerebellar arteries, this system supplies:

crus cerebri substantia nigra midbrain tegmentum The long circumferential branches originate mainly from the posterior cerebral artery, one important branch, the quadrigeminal (collicular artery) supplies the superior and inferior colliculi.

The spinal veins arranged in an _____________.

irregular pattern The anterior spinal veins run along the midline and the ventral roots. The posterior spinal veins run along the midline and the dorsal roots. These are drained by the anterior and posterior radicular veins. These in turn empty into an epidural venous plexus which connects into an external vertebral venous plexus, the vertebral, intercostal and lumbar veins.

Occlusions of long branches circumferential branches of the basilar artery produce a lateral pontine syndrome, characterized by:

lateral pontine syndrome: 1. Ataxia, due to damage to the cerebral peduncles (middle and superior) 2. Vertigo, nausea, nystagmus, deafness, tinnitus, vomiting, due to damage to vestibular and cochlear nuclei and nerves 3. Ipsilateral pain and temperature deficits from face, due to damage to the spinal trigeminal nucleus and tract 4. Contralateral loss of pain and temperature sense from the body, due to damage to the anterolateral system (spinothalamic) 5. Ipsilateral paralysis of facial muscles and masticatory muscles, due to damage to the facial and trigeminal motor nuclei (cranial nerves VII and V)

CVA Syndromes

• Middle Cerebral Artery - Most Common Ataxic Hemiparesis -Anatomy -Cerebral hemisphere: Posterior limb of external capsule, Pons: Basis pontis Vascular -Middle cerebral artery: Small penetrating arteries -Basilar artery: Small penetrating arteries Signs & Symptoms - Contralateral -Weakness & ataxia - upper and lower extremity. Comments -Weakness usually more prominent in lower than upper; extensor plantar response; no facial involvement or dysarthria.

CVA syndromes: Middle Cerebral Artery

• Middle Cerebral Artery. Gerstmann Syndrome Anatomy MCA - Cerebral hemisphere: Dominant parietal lobe. Signs & Symptoms -Agraphia, Acalculia, confusion, Finger agnosia, Ideomotor (hand gesture) apraxia.

Transient Ischemic Attack (TIA)

• Most likely an artery to the brain is temporarily blocked, or pressure through an occlusion drops below a point necessary to sustain normal neurological function, often when the patient is at rest. • The TIA causes stroke-like symptoms, but no apparent permanent damage occurs. • Some people just "brush off" the symptoms, especially when they last just a few minutes.

PATHOPHYSIOLOGY of Atherosclerosis

• Platelet Aggregation -Exposed subendothelium after injury to vessel. -Vessel collagen is exposed to blood, triggering "activation" of platelets. -Release of ADP from activated platelets causes platelet aggregation. -Consolidation of platelet-plug by RBCs, coagulation factors, and formatio of fibrin network. • Coagulation Cascade -A series of enzyme complexes located on the surface of platelets and endothelium which lead to thrombin production. -Thrombin (IIa) then converts Fibrinogen to Fibrin.

CVA syndromes: Cortical Blindness (Anton Syndrome)

• Posterior Cerebral Artery Cortical Blindness (Anton Syndrome). Anatomy - Cerebral hemisphere: Bilateral occipital lobes. -Vascular - Posterior cerebral artery: Bilateral; Basilar artery: Cephalad part. Signs & Symptoms Visual loss - bilateral Unawareness or denial of blindness.

Lacunar CVAs: pure motor

• Pure motor stroke/hemiparesis Most common lacunar syndrome: (33-50%) posterior limb of the internal capsule, basis pontis, corona radiata. It is marked by hemiparesis or hemiplegia that typically affects the face, arm, or leg of one side. Dysarthria, dysphagia, and transient sensory symptoms may also be present.

More Cerebrovascular Disease Statistics

• Stroke is the 4th leading cause of death in the United States. • In the US, stroke is the most common cause of neurologic disability in adults. • Of the more than 795,000 people affected every year, about 600,000 of these are first attacks, and 185,000 are recurrent. • About 25% of people who recover from their first stroke will have another stroke within five years.

Cerebrovascular Disease Statistics

• Stroke kills almost 130,000 Americans each year —that's 1 out of every 20 deaths. • Nearly three-quarters of all strokes occur in people over the age of 65. The risk of having a stroke more than doubles each decade after the age of 55. • Cerebrovascular disease is the most common life-threatening neurological event in the U.S.

Symptoms of Ischemic Stroke"HAFHAD"

•Carotid distribution Hemiparesis or monoparesis Facial weakness Hemisensory loss or neglect Aphasia Dysarthria Amaurosis fugax (fleeting blindness of one eye) • Vertebrobasilar distribution Vertigo Ataxia Dysarthria Dysphagia Dysmetria Visual phenomenon Scotoma Homonymous hemianopsia -Unilateral or bilateral weakness -Unilateral or bilateral sensory changes -"Crossed" weakness or numbness (ipsilateral face and contralateral body). -Total blindness (cortical blindness)

CLASSIFICATION OF CEREBROVASCULAR DISEASE

•Cerebrovascular Accident (CVA) AKA: Stroke Anterior Circulation: -Internal Carotid System -Vast Majority Posterior Circulation: Vertebrobasilar System - Rare - Manipulation? • Ischemic [65%-83%] -Vast Majority -Anoxia of Brain D/T Lack of Blood -Usually atherosclerotic disease. • Hemorrhagic -Less Common, more catastrophic -Ruptured Vessel Bleeds Into Brain (SOL)

Dural venous sinuses are areas where

the meningeal and periosteal layers separate to form large blood-filled spaces.

The radicular arteries provide the main blood supply to the cord at the ________, __________, and _______ segments.

thoracic, lumbar and sacral segments There are a greater number on the posterior (10-23) than anterior (6-10 only) side of the cord. One radicular artery, noticeably larger than the others, is called the artery of Adamkiewicz, or the artery of the lumbar enlargement. Usually located with the lower thoracic or upper lumbar spinal segment on the left side of the spinal cord The spinal cord lacks adequate collateral supply in some areas, making these regions prone to ischemia after vascular occlusions. The upper Thoracic (T1-T4) and first lumbar segments are the most vulnerable regions of the cord.

TIA

• About 30 percent of all people who suffer a major stroke experience a prior TIA. • 10 percent of all TIA victims suffer a stroke within two weeks. • Early intervention is essential and may effectively prevent a major stroke. • Treatment options for TIA patients focus on treating carotid artery disease or cardiac problems.

Uncontrollable & Untreatable Risk Factors for Stroke

• Age: People of all ages, including children, have strokes. But the older you are, the greater your risk of stroke. • Gender: Stroke is more common in men than in women. •Heredity: You have a greater risk of stroke if a parent, grandparent, sister or brother has had a stroke. • Race: Blacks have a much higher risk of death from a stroke than Caucasians do, partly because they are more prone to having high blood pressure, diabetes and obesity. • Prior stroke or heart attack: If the patient has had a stroke, they are at much higher risk of having another one. • Patients who have had a heart attack are also at higher risk of having a stroke.

Risk Factors for Stroke

• Although they are more common in older adults, strokes can occur at any age • Stroke prevention can help reduce disability and death caused by the disease

Marie-Foix Syndrome

• Anterior Inferior Cerebellar Artery - Uncommon. -Lateral Pontine Syndrome (Marie-Foix Syndrome) • Vascular - Basilar artery: Long circumferential branches; Anterior inferior cerebellar artery • Signs & Symptoms Ipsilateral Ataxia - arm and leg - Cerebellar tracts Contralateral Weakness - upper and lower extremity - Corticospinal tracts Contralateral Hemisensory loss - pain and temperature - Spinothalamic tract Lesion in the lateral pons, including the middle cerebellar peduncle.

AV Malformations

• Arteriovenous malformations (AVMs) are defects of the circulatory system that are generally believed to arise during embryonic or fetal development or soon after birth. • They are comprised of snarled tangles of arteries and veins. • The absence of capillaries creates a short- cut for blood to pass directly from arteries to veins.

Cardiac Conditions Associated with Embolization

• Atrial arrhythmias -Atrial fibrillation -Sick sinus syndrome -Valvular heart disease & othervegetations -Rheumatic valvular disease -Prolapsed mitral valve -Mitral annulus calcification -Prosthetic heart valves • Cardiac tumors -Myxoma • Ventricular endocardial thrombi - Acute myocardial infarction - Severe cardiomyopathy - Ventricular aneurysm

CLINICAL PRESENTATION OF STROKE #1

• Clinically, symptoms depend on the area of cerebral circulation affected and on the extent to which it is affected. 1. Internal Carotid Artery occlusion: a. Highly dependent upon dominant hemisphere for various functions. b. May range from a TIA to infarction of a major portion of the ipsilateral hemisphere. c. If adequate intracranial collateral circulation is present, may see no signs or symptoms. d. Neurological symptoms: monoparesis to hemiparesis with or without a defect in vision, impairment of speech or language, transient monocular blindness.

Lacunar CVAs

• Deep structure infarction, almost always occurring in patients with hypertension. • Lacunar = "empty space" Maximum deficit may be present immediately or may occur in a "stuttering" or slowly progressive fashion. The clinical differentiation of a typical lacunar syndrome from atherosclerotic syndromes is often difficult, but classic lacunar syndromes, especially pure motor hemiparesis, should be recognized so that unwarranted invasive diagnostic procedures may be avoided. • Treatment of lacunar strokes consists of treatment of underlying hypertension. • Since lacunar strokes involve deep structures (basal ganglia, internal capsule, brainstem), patients with lacunar stroke do not have aphasia, sensory neglect, visual field loss, or other deficits caused by cortical dysfunction. Small lacunar infarctions of deep structures may be seen on CT scan or MRI, and may be multiple. Depending on their location, some lacunar infarctions are asymptomatic.

Categories of Stroke Etiologies

• Intraluminal: -Thrombolic -Embolic • Dissection: -Traumatic - Rare - Chiropractors? -Spontaneous - "Non-Traumatic" • Extraluminal: -Kinks and Compression •Cardiac Origin • Blood Dyscrasias • Vasculitis • Hypotension (shock)

Etiologies of Stroke

• Ischemic: Extracranial atherosclerosis. Intracranial atherosclerosis. Embolism from heart. Intracranial vasculitis (several types). Increased blood viscosity or coagulability. Complicated migraine. Hypertensive arteriolar disease (lacunar stroke) Carotid dissection • Hemorrhage Intracerebral Subacrachnoid CAUSES: Hypertension (primary hypertensive hematoma). Saccular aneurysm Arteriovenous malformation Anticoagulant therapy Bleeding dyscrasias Amyloid angiopathy Hemorrhage into brain tumor Mycotic (infection) aneurysm Idiopathic

Controllable or Treatable Risk Factors for Stroke

-Smoking: Risk decreases with quitting. Risk may be increased further if you use some forms of oral contraceptives and are a smoker. There is recent evidence that long-term secondhand smoke exposure may increase the risk of stroke. -High blood pressure: Blood pressure of 140/90 mm Hg or higher is said to be the most important risk factor for stroke. -Carotid or other artery disease: A carotid artery narrowed by atherosclerosis plaques may become blocked by a blood clot. -History of transient ischemic attacks (TIAs) Diabetes: It is said to be crucial to control blood sugar levels, blood pressure, and cholesterol levels. Diabetes, especially when untreated?, puts the patient at much greater risk of stroke. High blood cholesterol: A high level of total cholesterol in the blood (240 mg/dL or higher) is a major risk factor for heart disease, which raises risk of stroke. High Blood Homocystine (>12 mmoles). Physical inactivity and obesity: Being inactive, obese or both can increase risk blood pressure, high blood cholesterol, diabetes, heart disease and stroke. People receiving hormone replacement therapy (HRT) have an overall 29 percent increased risk of stroke, in particular ischemic stroke.

CLASSIFICATION OF ISCHEMIC EVENTS - TIA

-Symptoms vary depending on the CNS anatomy involved -Drop Attacks -Amaurosis Fugax -No obvious clinical neurological deficit remains after the attack. -May vary from only one episode in a lifetime to > 20 in one day. -May be the only warning of an impending stroke.

The paramedian arteries, derived from the posterior communicating and posterior cerebral, form a plexus in the interpeduncular fossa, enter the through the posterior perforated substance, this system supplies:

-raphe region, -oculomotor complex -medial longitudinal fasiculus -red nucleus -substantia nigra -crus cerebri

Additional branches of the Basilar artery can be found branching off within the region of the Pons:

1. Anterior Inferior Cerebellar Arteries (AICA), originates near the lower borderof the Pons just past the union of the vertebral arteries. Distribution: a. supplies anterior inferior surface and underlying white matter of cerebellum b. contributes to supply of central cerebellar nuclei Blood Supply to the Pons c. medulla and lower pontine areas also contributes to upper

Branches of the Basilar Artery #1

1. Anterior Inferior Cerebellar Arteries (AICA), Originates near the lower border of the Pons just past the union of the vertebral arteries. Distribution: a. supplies anterior inferior surface and underlying white matter of cerebellum b. contributes to supply of central cerebellar nuclei c. also contributes to upper medulla and lower pontine areas

The Spinal Cord receives its blood supply from 2 major sources:

1. Branches of the vertebral arteries, the major source of blood supply, via the anterior spinal and posterior spinal arteries 2. Multiple radicular arteries, derives sporadically from segmental arteries

Interactive Metronome (IM) Training Goals #1

1. Improve neural timing & decrease neural timing variability (jitter) that impacts speech, language, cognitive, motor, & academic performance

Branches of the Vertebral Artery #1: PICA

1. Posterior Inferior Cerebellar Artery (PICA) -Largest branch of the vertebral, arises at the caudal end of the medulla on each side -Runs a course winding between the medulla and cerebellum Distribution: a. posterior part of cerebellar hemisphere b. inferior vermis c. central nuclei of cerebellum d. choroid plexus of 4th ventricle e. medullary branches to dorsolateral medulla

CLASSIFICATION OF ISCHEMIC EVENTS

1. Transient Ischemic Attacks (TIAs) -Episodes of a temporary reduction in perfusion to a focal region of the brain causing a short-lived disturbance of function. -The patient experiences a temporary focal neurological deficit such as slurred speech, aphasia, amaurosis fugax (monocular blindness), or weakness or paralysis of a limb. Onset is rapid; usually onset is less than 5 minutes. -Duration usually 2-15 minutes; can last up to 24 hours. -Longer than 24 hours and it is not a TIA. -Definition is changing to include "mini-strokes" whichmay be observed on MRI.

CLASSIFICATION OF ISCHEMIC EVENTS - a continuum

1. Transient Ischemic Attacks (TIAs) 2. Reversible Ischemic Neurological Deficit (RIND) 3. Cerebral Infarction

CLINICAL PRESENTATION #3

3. Anterior Cerebral Artery occlusion: a. Neurological symptoms: -Weakness of the opposite leg with or without sensory involvement -Apraxia (particularly of gait) -Possible cognitive impairment

CLASSIFICATION OF ISCHEMIC EVENTS #3

3. Cerebral Infarction - "Major Stroke" -A permanent neurological disorder -The patient presents with neurological deficits -Can present in 3 forms: 1. stable-the neurological deficit is permanent and will not improve or deteriorate. 2. improving-return of previously lost neurological function. 3. progressing-the neurological status continues to deteriorate following the initial onset of focal deficits; may see a stabilization period, followed by further progression.

Interactive Metronome (IM) Training Goals #3

3. Increase the brain's efficiency & performance & ability to benefit more from other rehabilitation & academic intervention

Branches of the Vertebral Artery #3: Posterior Spinal ARTERIES

3. Posterior Spinal Arteries (2) -Originate from each vertebral artery or Posterior Inferior Cerebellar on each side of the Medulla -Descends along the dorsolateral sulcus Distribution: supplies the dorsal 1/3 of the cord of each side.

Branches of the Basilar Artery #3

3. Superior Cerebellar arteries Originates near the end of the Basilar artery, close to the Pons-Midbrain junction. Runs along dorsal surface of cerebellum Distribution: a. cerebellar cortex, white matter and central nuclei b. pontine tegmentum, superior cerebellar peduncle and inferior colliculus

Branches of the Basilar Artery #4 and #5

4. Posterior cerebral arteries: The terminal branches of the Basilar artery. They appear as a bifurcation of the Basilar, just past the Superior Cerebellar arteries and the oculomotor nerve. Curves around the midbrain and reaches the medial surface of the cerebral hemisphere beneath the splenium of the corpus callosum Distribution: a. mainly neocortex and diencephalon b. some contribution to interpeduncular plexus 5. Labyrinthine arteries: May branch from the basilar, but variable in its origin. Supplies the region of the inner ear

Branches of the Vertebral Artery #4

4. Posterior meningeal One or two branches that originate from the vertebral opposite the foramen magnum. This branch moves into the dura matter of the cranium

CLINICAL PRESENTATION #4

4. Vertebrobasilar system: a. Neurological symptoms: -severe vertigo -nausea -vomiting -dysphagia -ipsilateral cerebellar ataxia -decreased pain and temperature discrimination -diplopia -visual field loss -gaze palsies

Branches of the Vertebral Artery #5

5. Bulbar branches Composed of several smaller arteries whichoriginate from the vertebral and it's branches. These branchessupply the pons, medulla and cerebellum

If a patient sustained an ischemic stroke involving the left middle cerebral artery and a major lesion of the left supramarginal gyrus was sustained, which of the following may be their primary clinical feature? a. astereognosis b. finger agnosia c. errors in spelling and writing d. all of the above would occur

ALL OF THE ABOVE

CLASSIFICATION OF ISCHEMIC EVENTS- Amaurosis Fugax

A specific type of TIA where there is sudden loss of vision in one eye. Resolves quickly and spontaneously. Occurs when debris from the ipsilateral carotid artery occludes one of the ophthalmic arteries (terminal branch if the internal carotid artery) cutting blood supply to the retina.

Circle of Willis

A structure at the base of the brain that is formed by the joining of the carotid and basilar arteries. The vertebral arteries originate from the subclavian artery, and ascend through the transverse foramen of the upper 6 cervical vertebra. At the upper margin of the Axis (C2) it moves outward and upward to the transverse foramen of the Atlas (C1). It then moves backwards along the articular process of atlas into a deep groove, passes beneath the at lantooccipital ligament& enters the foramen magnum. The arteries then run forward and unite at the caudal border of the pons to form the basilar artery.

superior sagittal sinus

A venous sinus located in the midline just dorsal to the corpus callosum, between the two cerebral hemispheres. blue cavity surrounding the brain which collects blood draining from the brain tissue

Arteriovenous malformations (AVMs)

Although AVM's can develop in many different sites, many dangerous ones are located in the brain or spinal cord. AVMs of the brain or spinal cord are believed to affect approximately 300,000 Americans. They occur in males and females of all racial or ethnic backgrounds at roughly equal rates.

CVA syndromes: Middle Cerebral Artery - Inferior Division

• Middle Cerebral Artery - Inferior Division Contralateral -Visual loss - homonymous hemianopia -Visual loss - upper quadrant anopsia -Constructional apraxia - Non-dominant hemisphere. -Aphasia - receptive - Dominant hemisphere (Wernicke's area)

CAUSES OF CEREBRAL HEMORRHAGES

Aneurysms: -Size varies -Small "berry" type prone to sudden rupture -Large no problem, slow leak, sudden rupture. AV Malformations: -Slow leak - sudden rupture Hematomas: -Trauma, tumor, vascular anomalies, vasculitis, high blood pressure, etc. -Epi/Sub-dural -Sub-Arachnoid hematoma

Spinal Cord blood supply: anterior/posterior

Anterior Spinal Artery: provides sulcal branches which penetrate the ventral median fissure and supply the ventral 2/3 of the spinal cord. Posterior Spinal Arteries: each descends along the dorsolateral surface of the spinal cord and supplies the dorsal 1/3.

cortical vascular territories

Anterior cerebral artery supplies most of corpus callousm- in the area of somatosensory cortex and primary motor... so lots of lower body disability Damage to posterior can cause cortical blindness Middle covers pre and post central gyrus

Ataxic hemiparesis: Lacunar CVA's

Ataxic hemiparesis Second most frequent lacunar syndrome. Posterior limb of the internal capsule, basis pontis, and corona radiata, red nucleus, lentiform nucleus. It displays a combination of cerebellar and motor symptoms, including weakness and clumsiness, on the ipsilateral side of the body. It usually affects the leg more than it does the arm.The onset of symptoms is often over hours or days.

PATHOPHYSIOLOGY

Atherosclerosis and subsequent plaque formation results in arterial narrowing or occlusion and is the most common cause of arterial stenosis. Atherosclerosis and plaque deposition are typically found at the bifurcation of medium sized arteries. Thrombus formation is most likely to occur in areas where atherosclerosis and plaque deposition have caused the greatest narrowing of vessels.

CVA syndromes: Basilar artery

Basilar Artery. Ataxic Hemiparesis. Cortical Blindness. Foville Syndrome. Anatomy - Pons: Unilateral lesion in the dorsal pontine tegmentum in the caudal third of the pons. Vascular - Basilar artery: Paramedian branches & Short circumferential arteries Signs & Symptoms ContralateralWeakness - upper and lower extremity - Corticospinal tract. Ipsilateral Weakness - face - entire side - VII nucleus/fascicle. Ipsilateral Lateral gaze weakness CN VI nucleus.

The Medulla, Pons and Midbrain areas receive their major sources of blood supply from several important branches of the

Basilar artery

superior sagittal sinus vein

CSF exits across the arachnoid granulations into the _____________________________

What system drain the venous of the orbit?

Cavernous sinus

Obstruction of the paramedian pontine arteries will produce a middle alternating hemiplegia (also termed medial pontine syndrome) which is characterized by;

MEDIAL PONTINE SYNDROME 1. Hemiplegia of the contralateral arm and leg, due to damage to the corticospinal tracts 2. Contralateral loss of tactile discrimination, vibratory and position sense, due to damage to the medial leminiscus 3. Ipsilateral lateral rectus muscle paralysis, due to damage to theabducens nerve or tract (can cause diplopia "double vision")

More skull coverings

Diploe Outer table Inner table Endocranium + Dura Arachnoid Piamater

What structure is NOT associated with the cavernous sinus? A. CN III B. CN IV C. CN V D. CN VI E. CN VII F. Pituitary gland G. ICA

E. CN VII The oculomotor (III), trochlear (IV), and abducens (VI) cranial nerves are associated with cavernous sinus, along with the pituitary gland, the internal carotid artery (ICA), V1 and V2.

CVA (stroke) statistics

L - Lagging Face A - Arm don't work M - Mouth don't work E - Emergency Room F - Face drooping A - Arm weakness S - Speech difficulty T - Time to call 911

Lacunar CVAs • Mixed sensorimotor stroke

Lacunar CVAs • Mixed sensorimotor stroke Thalamus and adjacentposterior internal capsule, lateral pons. This lacunar syndrome involves hemiparesis or hemiplegia with ipsilateral sensory impairment.

Lacunar CVAs •Pure sensory stroke

Lacunar CVAs •Pure sensory stroke Contralateral thalamus (VPL), internal capsule, corona radiata, midbrain. Marked by persistent or transient numbness, tingling, pain, burning, or another unpleasant sensation on one side of the body.

CLASSIFICATION OF ISCHEMIC EVENTS- Drop Attacks

May be due to TIA. The patient falls suddenly without warning, without (maybe with) losing consciousness, occurring as a result of cerebellar ischemia.

CVA syndromes: Middle Cerebral Artery - Superior Division

Middle Cerebral Artery - Superior Division Signs & Symptoms Contralateral -Weakness - upper and lower extremity, Face, arm > leg -Weakness - face - lower half (spares forehead) -Hemisensory loss - upper and lower extremity -Sensory loss - face - all modalities -Hemineglect - Non-dominant hemisphere -Aphasia - Oral Expressive - Dominant hemisphere (Broca's area).

mirror therapy

Motor re-training method that includes using the reflection of the unaffected limb, typically used as an adjunct intervention for: complex regional pain syndrome phantom limb pain hemiparesis

Spinal cord blood supply continued

Radicular arteries: originating from segmental arteries atvarious levels, which divide into anterior and posterior radicular arteries as they move along ventral and dorsal roots to reach the spinal cord. Here they reinforce spinal arteries and anastomose with their branches. From these varied sources of blood supply, a series of circumferential anastomotic channels are formed around the spinal cord, called the arterial vasocorona, from which short branches penetrate and supply the lateral parts of the cord

There are several arteries that reinforce the spinal cord blood supply and are termed segmental arteries:

SEGMENTAL ARTERIES: 1. The Vertebral arteries, spinal branches which are present in the upper cervical (~C3-C5) levels 2. Ascending Cervical arteries, present in the lower cervical areas 3. Posterior Intercostal, present in the mid-thoracic region 4. First Lumbar arteries, present in the mid-lumbar regions

Skull bone coverings

Scalp Pericranium Diploe Dura

CVA: BASILAR ARTERY

Signs & Symptoms. -Bilateral Weakness - upper and lower extremity, Quadriplegia: bilateral cortical spinal tracts. -Weakness - face - entire side - Bilateral corticobulbar tracts -Lateral gaze weakness - Bilateral fascicles of CN VI. - Dysarthria - Bilateral corticobulbar tracts.

TIA treatment

There is no treatment for the TIA itself. It is essential that the source of the TIA be identified and appropriately treated before another attack occurs. A TIA requires immediate and urgent medical attention. Notify the patient as well as their primary care physician immediately

tPA's

Tissue plasminogen activator - tPA - dissolves clots & restores blood flow. Given as soon as possible after a stroke to avoid neuronal apoptosis. Initially a six-hour window, but current recommendations discourage TPA use more than three hours after onset of a stroke. European clinical trials found that selected patients still benefit from TPA up to 4 1/2 hours after a stroke. Patients who cannot receive tPA more than three hours after a stroke: Patients over age 80. Patients taking anticoagulants. Patients with a history of stroke and diabetes.

Superior sagittal sinus

Tributaries- Superior Cerebral veins - Diploic & Emissary veins through lacunae Communications- Veins of scalp through emissary veins - Vein from nose through foramen caecum (rare) - Cavernous sinus thru superior anastomotic vein Applied anatomy - Infection from nose, scalp, diploic tissue leads to thrombosis of superior/saggittal. Sinus- Defective absorption of CSF - increased intracranial tension

Dural venous sinuses

Unpaired 1. Superior sagittal 2. Inferior sagittal 3. Straight 4. Occipital 5. Anterior Intercavernous 6. Posterior Intercavernous 7. Basilar venous plexus Paired 1. Transverse 2. Sigmoid 3. Cavernous 4. Superior Petrosal 5. Inferior Petrosal 6. Sphenoparietal 7. Petrosquamous 8. Middle meningeal

Spinal Cord blood supply

VENTRAL vs. DORSAL

The posterior spinal arteries supply the?

gracile and cuneate fasciculi and nuclei, spinal trigeminal tract and nucleus, and portions of the inferior cerebellar peduncle

BLOOD SUPPLY TO MEDULLA: Occlusion of branches of the anterior spinal artery will produce a inferior alternating hemiplegia (aka characterized by; medial medullary syndrome)

inferior alternating hemiplegia (aka characterized by;medial medullary syndrome) 1. A contralateral hemiplegia of the limbs, due to damage to the pyramids or the corticospinal fibers 2. A contralateral loss of position sense, vibratory sense and discriminative touch, due to damage to the medial leminiscus 3. An ipsilateral deviation and paralysis of the tongue, due to damage to the hypoglossal nucleus or nerve Occasionally, these symptoms will develop after occlusion of the vertebral artery before gives off its branches to the anterior spinal artery

Occlusion of the posterior spinal arteries may lead to the rare posterior cord syndrome, characterized by:

posterior cord syndrome: 1. Ipsilateral motor deficits, due to damage to corticospinal tract 2. Ipsilateral loss of tactile discrimination, position sense, vibratory sense, due to damage to the dorsal columns *RARE*