3.5/3.6 Clinical Decision Making: Hemorrhagic/Ischemic Stroke_Acute Neurological Deficits Scheme

Question 1

Differentiating Stroke from Other Neurologic Causes

Answer 1

Differentiate based upon:
Presenting symptoms
Contributing medical/physical disorders 
Onset 
Depressed or altered level of consciousness
Focal neurological deficits
Comorbidities

Examples of other neurologic causes: Syncope, seizure, migraine, head trauma, and psychiatric illness.

Question 2

Onset of neurologic deficits in stroke

Answer 2

Neurologic deficits are sudden onset and persist > than 24 hours.

Question 3

Two Major Mechanisms that Produce Strokes

Answer 3

-Blockage of an artery (80% of strokes)
Ischemia (inadequate blood flow) deprives the brain of oxygen, glucose, and slows waste removal .
Affected brain tissue functions abnormally or stops functioning, and will die if ischemia persists.

-Rupture of an artery (20% of strokes)
Hemorrhage within or around the brain distorts, compresses, and injures brain tissue.

Question 4

Contributing medical disorders: CEREBROVASCULAR DISEASE

Answer 4

Cerebrovascular disease is a heterogeneous disease. A stroke occurs when a blood vessel that supplies oxygen and nutrients to the brain becomes blocked or ruptures. A portion of the brain dependent on blood flow from this vessel becomes deprived of oxygen. Within minutes, nerve cells begin to die, which results in permanent disability.

Question 5

Stroked affect which ethnic group the most?

Answer 5

African Americans
-African Americans suffer more extensive physical impairments
-Twice as likely to die from stroke
-Disproportionately high incidence of risk factors for stroke:
   Hypertension
   Diabetes
   Obesity
   Smoking
   Sickle cell anemia

Question 6

Common Neurologic Deficits caused by stroke

Answer 6

• Weakness or paralysis, usually one side only
• Loss of sensation, usually one side only
• Problem with vision
• Difficulty in talking or understanding what is said
• Difficulty with organizing thoughts or perception
• Clumsiness or lack of balance

Question 7

Major regions supplied by carotid circulation

Answer 7

Cortex and deep white matter
    -Frontal and parietal lobes
    -Lateral parts of the temporal and occipital lobes
Basal ganglia
Internal capsule

Question 8

Key functional areas supplied by ACA

Answer 8

Primary motor cortex

• Leg and foot areas*
• Control urinary bladder
• Motor planning areas in medial frontal lobe, anterior to the precentral gyrus
• Primary somatosensory cortex for leg and foot

Question 9

Key functional areas supplied by MCA

Answer 9

-Primary motor cortex - face / arm areas
-Primary somatosensory cortex - face / arm areas
-Frontal/parietal - language-dominant hemisphere
+Broca’s - language expression
-Frontal/parietal - nondominant hemisphere
+Area for visuospatial concepts of self and world
-Temporal/Parietal - language-dominant hemisphere
+Wernicke’s - language comprehension
-Visual Radiations
-Frontal eye fields

Question 10

Major Regions Supplied by Vertebral-Basilar Circulation

Answer 10

-Brainstem and cerebellum
-Most of thalamus and hypothalamus
-Cortex and deep white matter
Posterior medial parietal lobes
Medial temporal and occipital lobes

Question 11

Key functional areas supplied by PCA

Answer 11

-Cortical branches - parietal and occipital lobes
+Visual radiations and primary visual cortex
-Cortical branches - medial temporal lobe
+Hippocampal formation

Question 12

Symptoms of patient presenting vascular problem in carotid circulation?

Answer 12

-One-sided limb weakness, clumsiness or paralysis
-One-sided numbness, paresthesia, or sensory loss
-Difficulty with language production or comprehension
-Inability to articulate words clearly,
‘I slurred my words’ - dysarthria

Question 13

Symptoms of patient presenting vascular problem in vertebral-basilar circulation?

Answer 13

Various combinations - 2 at least

• Vertigo or dizziness
• Unilateral or bilateral weakness or clumsiness
• Unilateral or bilateral numbness or sensory loss
• Limb ataxia or coarse tremor, staggering gait
• Dysarthria
• Visual field defect, blindness, or diplopia

Question 14

Stroke Neurologic Symptoms - Anterior Circulation

Answer 14

Anterior Circulation:
-Dominant hemisphere syndrome (usually left)
+right hemiparesis and hemisensory loss, left gaze preference, right visual field cut, and aphasia.

-Nondominant hemisphere syndrome (usually right)
+left hemiparesis and hemisensory loss, right gaze preference, left visual field cut and neglect with left-sided hemi-inattention ignoring the left side.

Question 15

Stroke Neurologic Symptoms - Posterior Circulation

Answer 15

Posterior Circulation: (Can have mixed sign )

• Gait or limb ataxia
• Vertigo or tinnitus
• Nausea and vomiting
• Hemiparesis or quadriparesis
• Hemisensory loss or sensory loss of all 4 limbs
• Eye movement abnormalities resulting in diplopia or nystagmus
• Oropharyngeal weakness or dysphagia
• Crossed signs (ipsilateral face and contralateral body)

Question 16

What is a TIA?

Answer 16

Transient Ischemic Attack - brief episode in which neurologic deficits suddenly occur then disappear

• last minutes to hours
• no permanent damage
• indicates future ischemic stroke
• Treatment of TIA can reduce risk of stroke
• TIAs in carotid territory predict severe atherosclerosis in the proximal internal carotid artery.
• The risk of stroke is highest during the first month. 15-30% of subsequent strokes occur during the first month and 40-50% during the first year.
• Because the episode of impaired function is brief, patients may not tell you about it unless you ask.