Flashcards in CN LANGE - Stroke II Deck (113):
Temporary occlusion of one or both vertebral arteries can also result from ...?
Rotating the head in patients with cervical spondylosis, leading to transient brainstem dysfunction.
Is subclavian steal syndrome any stroke predictive value in the vertebrobasilar system?
Basilar thrombosis usually affects the ... basilar artery.
PROXIMAL - Supplies the PONS.
Involvement of the dorsal pons (tegmentum) produces ...?
1. Unilateral or bilateral VI nerve palsy.
2. Horizontal eye movements are impaired, but vertical nystagmus and ocular bobbing may be present.
3. The pupils are constricted due to involvement of descending SNS pupillodilator fibers, but may be reactive.
4. Hemiplegia or quadriplegia is usually present, and coma is common.
In some patients, the ventral pons (basis pontis) is infarcted and the tegmentum is spared. Such patients remain ...?
Conscious but quadriplegic (locked-in syndrome).
Locked-in syndrome - EEG?
Normal EEG further distinguishes the locked-in state from coma.
Basilar artery - Embolism:
1. Interruption of blood flow to the ascending reticular formation in the midbrain and thalamus produces immediate loss or impairment of consciousness.
2. Unilateral/bilateral oculomotor (III) nerve palsies are characteristic.
3. Hemiplegia or quadriplegia with decerebrate or decorticate posturing results from involvement of the cerebral PEDUNCLES in the midbrain.
The top of the basilar syndrome may be confused with ...?
Midbrain damage caused by transtentorial uncal herniation.
Smaller emboli may occlude the rostral basilar artery transiently before fragmenting and passing into one or both PCAs. In such cases, portions of the midbrain, thalamus, and temporal and occipital lobes can be infarcted. Patients may display:
1. Visual (homonymous hemianopia, cortical blindness).
2. Visuomotor (impaired convergence, paralysis of upward or downward gaze, diplopia).
3. Behavioral (especially confusion) abnormalities without prominent motor dysfunction.
What is a helpful sign of midbrain involvement?
Sluggish pupillary responses.
The long circumferential branches of the vertebral and basilar arteries are the:
3. Superior cerebellar.
The long circumferential vertebrobasilar branches supply:
1. Dorsolateral brainstem.
2. Including dorsolateral cranial nerve nuclei (V, VII, and VIII).
3. Pathways entering and leaving the cerebellum in the cerebellar peduncles.
PICA occlusion - Wallenberg syndrome - Presentation:
1. Ipsilateral cerebellar ataxia.
2. Horner syndrome.
3. Facial sensory deficit.
4. Contralateral impaired pain and temp sensation.
5. Nystagmus, vertigo, nausea, vomiting.
Wallenberg syndrome - What is characteristically spared?
The MOTOR system because of its ventral location in the brainstem.
Infarction of the lateral portion of the caudal pons and produces many of the PICA features.
+ Ipsilateral facial weakness, gaze palsy, deafness, and tinnitus are common.
AICA occlusion - Which PICA occlusion features do NOT occur?
Superior cerebellar artery occlusion causes ...?
Lateral rostral pontine infarction and resembles AICA lesions.
Superior cerebellar artery occlusion - Differences with AICA occlusion?
1. Impaired optokinetic nystagmus or skew deviation of the eyes may occur.
2. Auditory function is unaffected.
3. The contralateral sensory disturbance may involve touch, vibration, and position sense as well as pain and temp sense.
Long penetrating paramedian vertebrobasilar branches supply:
1. Medial portion of the cerebral peduncle.
2. Sensory pathways.
3. Red nucleus.
4. Reticular formation.
5. Midline cranial nerve nuclei (III, IV, VI, XII).
Long penetrating paramedian vertebrobasilar branches - Occlusion:
1. Paramedian infarction of the brainstem and results in contralateral hemiparesis if the cerebral peduncle is affected.
2. Associated cranial nerve involvement depends on the level of the brainstem at which occlusion occurs.
Long penetrating paramedian vertebrobasilar branches - Occlusion in the midbrain results in ...?
Ipsilateral III nerve palsy, which may be associated with contralateral tremor or ataxia from involvement of pathways connecting the red nucleus and cerebellum.
Long penetrating paramedian vertebrobasilar branches - Occlusion in the pons results in ...?
Ipsilateral VI and VII nerve palsies are seen with lesion in the pons.
Long penetrating paramedian vertebrobasilar branches - Occlusion in the medulla:
XII nerve involvement.
Short basal vertebrobasilar branches:
Short branches arising from the long circumferential arteries penetrate the ventral brainstem to supply the brainstem MOTOR pathways.
Short basal vertebrobasilar branches - The most striking finding is ...?
Contralateral hemiparesis caused by corticospinal tract involvement in the cerebral peduncle or basis pontis.
--> CN (III, VI, VII) that emerge from the ventral surface of the brainstem may be affected as well, giving rise to ipsilateral cranial nerve palsies.
Small vessel occlusion affecting penetrating arteries deep in the brain may cause infarcts in the putamen or, less commonly:
1. The thalamus.
2. Caudate nucleus.
4. Posterior limb of the internal capsule.
5. Other sites.
Lacunar strokes develop over ...?
Hours to days.
The prognosis for recovery from a lacunar stroke is ...?
GOOD - But recurrent stroke is common.
The 4 classic and distinctive lacunar syndromes:
1. Pure motor hemiparesis.
2. Pure sensory stroke.
3. Ataxic hemiparesis.
4. Dysarthria-clumsy hand syndrome.
Pure motor hemiparesis:
This consists of hemiparesis affecting the face, arm, and leg to a roughly equal extent, without associated disturbance of sensation, vision, or language.
Pure motor hemiparesis - Lacunes that produce this syndrome are usually located ...?
In the contralateral internal capsule or pons.
Pure motor hemiparesis may also be caused by ...?
1. ICA or MCA occlusion.
2. Subdural hematoma.
3. Intracerebral mass lesions.
Pure sensory stroke:
Hemisensory loss, which may be associated with paresthesia, and results from lacunar infarction in the contralateral thalamus.
Pure sensory stroke - May be mimicked by ...?
1. Occlusion of the PCA.
2. Small hemorrhage in the thalamus/midbrain.
Ataxic hemiparesis (ipsilateral ataxia and crural (leg) paresis):
Pure motor hemiparesis is combined with ataxia of the hemiparetic side and usually affects the leg predominantly.
Ataxic hemiparesis - Symptoms result from a lesion in the:
1. Contralateral pons.
2. Internal capsule.
3. Subcortical white matter.
Dysarthria-clumsy hand syndrome:
2. Facial weakness.
4. Mild weakness + clumsiness of the hand on the side of facial involvement.
Dysarthia-clumsy hand involvement - Lacunes causing this syndrome are located in ...?
Contralateral pons or internal capsule.
Dysarthria-clumsy hand syndrome - What may produce a similar syndrome?
Infarcts or small intracerebral hemorrhages at a variety of locations can produce a similar syndrome.
Are TIAs common in dysarthria-clumsy hand syndrome?
In contrast to the other lacunar syndromes, premonitory TIAs are unusual.
Focal cerebral ischemia - Etiology:
Disorders that primarily affect the:
2. Blood vessels.
Atherosclerosis - Within the cerebral circulation, the sites of predilection are:
1. Common carotid.
2. ICA just above the bifurcation.
3. ICA within the cavernous sinus.
4. The origin of the MCA.
5. The origin of vertebral artery + Just above where it enters the skull.
6. Basilar artery.
VASCULAR conditions associated with focal cerebral ischemia:
2. Other inflammatory disorders: Giant cell arteritis, SLE, PAN, 1o angiitis of the CNS, syphilitic arteritis, AIDS.
3. Non-inflammatory cerebrocervical arteriopathies: Fibromuscular dysplasia, carotid or vertebral artery dissection, moyamoya (multiple progressive intracranial occlusions).
4. Lacunar infarction.
5. Drug abuse.
7. Venous or sinus thrombosis.
CARDIAC conditions associated with focal cerebral ischemia:
3. Mechanical valves.
5. Rheumatic mitral stenosis.
7. Marantic endocarditis.
8. Atrial myxoma.
9. Paradoxical embolus.
HEMATOLOGIC conditions associated with focal cerebral ischemia:
5. Hypercoagulable states.
Giant cell arteritis produces inflammatory changes that affect branches of:
1. External carotid.
2. Cervical internal carotid.
3. Posterior ciliary.
4. Extracranial vertebral.
5. Intracranial arteries.
Giant cell arteritis should be considered in patients with ...?
Transient monocular blindness or transient cerebral ischemic attacks - especially the elderly - because steroids can prevent its complications.
SLE is associated with ...?
A vasculopathy that involves SMALL cerebral vessels and leads to multiple microinfarctions.
--> Inflammatory changes characteristic of TRUE vasculitis are ABSENT.
SLE - What may be a source of cardiogenic emboli?
Transient symptoms of cerebral ischemia, including typical spells of transient monocular blindness, can occur.
Primary angiitis of the CNS (also referred to as granulomatous angiitis) is an ...?
Idiopathic inflammatory disease that affects small arteries + veins in the CNS --> Cause transient or progressive multifocal ischemic lesions.
Primary angiitis of the CNS - Clinical features:
3. Other focal neurologic abnormalities.
4. Cognitive disturbances.
Primary angiitis of the CNS - CSF:
Pleocytosis + elevated protein.
--> ESR is NORMAL because systemic vasculature is typically SPARED.
Primary angiitis of the CNS - Angiography:
Demonstrates focal and segmental narrowing of small arteries + veins.
Primary angiitis of the CNS - What is diagnostic?
Occurs within 5yrs after primary syphilitic infection and may cause stroke.
Syphilitic arteritis - Which vessels are involved?
Medium-sized penetrating vessels are typically involved, producing punctuate infarcts in the deep cerebral white matter --> Can be seen on CT or MRI.
AIDS is associated with an increased incidence of ...?
TIAs and ischemic stroke.
Non-inflammatory cerebrocervical arteriopathies - Fibromuscular dysplasia:
Produces segmental medial fibroplasia of large (especially renal, carotid, and vertebral) arteries.
Fibromuscular dysplasia is associated with ...?
Arterial dissection and aneurysms.
Fibromuscular dysplasia - Familial cases suggest?
AD inheritance with incomplete penetrance.
Fibromuscular dysplasia - Stroke is MC in ...?
CHILDREN and young/middle-aged adults (esp. females).
Carotid or vertebral artery dissection may occur ...?
Spontaneously or in response to minor trauma, and is MC in middle age.
Carotid artery dissection may be accompanied by ...?
1. Prodromal transient hemispheric ischemia or monocular blindness
2. Jaw pain or neck pain.
3. Visual abnormalities that mimic those seen in migraine.
4. Horner syndrome.
Vertebral dissection may produce ...?
2. Neck pain.
3. Signs of brainstem dysfunction.
Multiple progressive intracranial arterial occlusions (moyamoya):
BILATERAL narrowing or occlusion of the distal ICAs + adjacent ACA + MCA trunks.
Moyamoya may be idiopathic, or ...?
Due to atherosclerosis, SCA, or other arteriopathies.
Moyamoya is MC in ...?
Children and middle-aged adults, and more common in females than males, but occurs in all ethnic groups, and may be sporadic or inherited.
Moyamoya - Children tend to present with ...?
Moyamoya - Adults tend to present with ...?
Intracerebral, subdural, or SAH.
Drug abuse - Cocaine hydrochloride and amphetamines are most often associated with ...?
Stroke from alkaloidal (crack) cocaine use is usually ...?
Migraine as a cause of stroke?
Migraine with (but NOT without) aura is a rare cause of ischemic stroke, which is MC in:
Migraineus exhibit higher incidence of:
1. Subclinical white matter lesions in the posterior circulation.
2. Patent foramen ovale.
3. Cervical artery dissection.
--> The relationship of these factors to clinical stroke is UNCERTAIN.
Sporadic or familial (AD) hemiplegic migraine is associated with ...?
Focal cerebral edema during attacks and with cerebellar atrophy, but NOT WITH STROKE.
Venous or sinus thrombosis - Predisposing conditions:
3. Postpartum state.
Venous or sinus thrombosis - CT:
4. Filling defect in the superior sagittal sinus (delta sign).
Venous or sinus thrombosis - Most definitive diagnostic test:
MRI with MR angiography.
A-fib - Increases stroke risk ...?
2- to 7-fold.
--> 17-fold when valvular disease is also present.
MI is followed by stroke, usually cardioembolic, within 1 month in about ...% of patients.
Which valve prostheses are typically associated with a higher risk of thromboembolic complications?
Mitral valve prostheses > Aortic valve prostheses.
DCM - Therapy?
Neither antiplatelet therapy nor anticoagulation has been shown to be of clear benefit for patients with DCM in normal sinus rhythm.
Noninfectious (marantic) endocarditis is most frequent in patients with cancer + causes the majority of ischemic strokes in this population.
Marantic endocarditis - Tumors most often associated with this type of stroke are:
1. Adenocarcinomas of the lung.
2. GI tract.
Hematologic disorders - Thrombocytosis - Risk factors for arterial thrombosis in essential thrombocytosis include:
1. Age >60.
2. History of thrombotic events.
3. Cardiovascular risk factors (HTN, DM, smoking).
5. JAKV617F mutation.
Extremely high platelet counts are paradoxically ...?
PROTECTIVE against thrombosis, probably because of an association with acquired structural or functional defects in vWF.
Cerebrovascular complications of SCA include:
Ischemic stroke which usually involves:
1. Large (intracranial ICA or proximal MCA or ACA).
2. Less commonly - Aneurysmal SAH.
Stroke occurs in more than ...% of patients with homozygous SCA by age 20.
Patients with sickle cell disease who require angiography should first receive ...?
Exchange transfusion to reduce HbS to less than 20%, because radiologic contrast media may induce sickling.
Leukocytosis - Ischemic stroke can occur in patients with leukemia:
BUT the role of leukocytosis itself is UNCLEAR.
--> Hemorrhage is more common in this setting.
Even mild leukocytosis is associated with an increased incidence of thrombosis in patients with POLYCYTHEMIA VERA, but ...?
May NOT be an independent risk factor.
Causes of hypercoagulable states that may be associated with stroke include:
1. Paraproteinemia (especially macroglobulinemia).
2. Estrogen therapy.
4. Postpartum + post-op states.
6. Antiphospholipid antibodies.
8. Hereditary coagulopathies (protein S def, factor V Leyden mutation, prothrombin mutation).
Clinical findings - History - Features suggesting thrombotic stroke:
1. Stepwise progression of neurologic deficits.
2. May be preceded by one or more TIAs with identical symptoms.
3. Lacunar infarcts are also characteristically thrombotic.
Clinical findings - History - Features suggesting embolic stroke:
1. Maximal deficit within 5mins of onset.
2. Impaired consciousness at onset
3. Sudden regression of deficit.
4. Multifocal infarction.
5. Wernicke or global aphasia without associated hemiparesis.
6. Top of the basilar syndrome.
7. Hemorrhagic transformation of infarct.
8. Associated valvular disease, cardiomegaly, arrhythmia, or endocarditis.
Clinical findings - History - Associated symptoms - Headache:
Present at onset in about 25% of patients with ischemic stroke and is especially common in intracranial arterial dissection and venous or sinus thrombosis.
Clinical findings - History - Associated symptoms - Seizures:
Seizures can accompany the onset of stroke or follow stroke by weeks to years, but do NOT definitively distinguish embolic from thrombotic stroke.
Physical examination - General physical exam:
2. Comparison of BP + pulse on the 2 sides.
3. Ophthalmoscopic exam.
4. Neck exam.
5. Cardiac exam.
6. Temporal artery palpation.
7. Skin exam.
Ophthalmoscopic exam of the retina:
Provide evidence of embolization in the anterior circulation, in the form of visible embolic material in retinal blood vessels.
1. May reveal absence of the carotid pulses or the presence of carotid bruits.
2. Reduced carotid artery pulsation in the neck is a poor indicator of ICA disease.
3. Significant carotid stenosis can occur WITHOUT an audible bruit.
4. A loud bruit can occur WITHOUT stenosis.
Neurologic exam - Cognitive deficits such as aphasia, unilateral neglect or constructional apraxia suggest a ...?
Cortical lesion in the anterior circulation and exclude vertebrobasilar or lacunar stroke.
--> Coma implies brainstem or bihemispheric involvement.
Neurologic exam - Visual field abnormalities exlude:
Visual field abnormalities can occur with occlusion of ...?
Either the MCA or the PCA, which supply the optic radiation and visual cortex, respectively.
Isolated hemianopia suggests ...?
PCA stroke, because MCA stroke should produce additional (motor + somatosensory) deficits.
Ocular palsy, nystagmus, or INO assigns the underlying lesion to the ...?
BRAINSTEM - Posterior circulation.
Hemiparesis can be due to lesions:
1. Cortical regions supplied by the anterior circulation.
2. Descending motor pathways in the brainstem supplied by the vertebrobasilar system.
3. Lacunes at subcortical or brainstem sites.
Hemiparesis affecting the face, hand, and arm more than the leg is characteristic of ...?
Hemiparesis affecting the face, arm, and leg to a similar extent is consistent with ...?
Large vessel stroke in the ICA, MCA stem, or vertebrobasilar distribution, or with lacunar infarction.
Crossed hemiparesis, which involves the face on one side and the rest of the body on the other, assigns the lesion to the ...?
Brainstem between the VII nucleus in the pons and the decussation of the pyramids in the medulla.
Cortical sensory deficits such as astereognosis or agraphesthesia, with preserved primary sensory modalities, imply a cortical deficit within the ...?
Hemisensory deficits WITHOUT associated motor involvement are usually ...?
Crossed sensory deficits result from ...?
Lesions in the medulla, as seen in the lateral medullar syndrome (Wallenberg).
Hemiataxia usually points to a lesion in the ...?
IPSILATERAL brainstem or cerebellum, but can also be produced by lacunar stroke in the internal capsule.