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Page: Signs and Symptoms
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The symptoms of stroke depend on the type of stroke and the area of the brain affected. Ischemic strokes usually only affect regional areas of the brain perfused by the blocked artery. Hemorrhagic strokes can affect local areas, but often can also cause more global symptoms due to bleeding and increased intracranial pressure.
If the area of the brain affected contains one of the three prominent Central nervous system pathways—the spinothalamic tract, corticospinal tract, and dorsal column (medial lemniscus), symptoms may include:
* muscle weakness (hemiplegia)
* numbness
* reduction in sensory or vibratory sensation
In most cases, the symptoms affect only one side of the body. The defect in the brain is usually on the opposite side of the body (depending on which part of the brain is affected). However, the presence of any one of these symptoms does not necessarily suggest a stroke, since these pathways also travel in the spinal cord and any lesion there can also produce these symptoms.
In addition to the above CNS pathways, the brainstem also consists of the 12 cranial nerves. A stroke affecting the brainstem therefore can produce symptoms relating to deficits in these cranial nerves:
* altered smell, taste, hearing, or vision (total or partial)
* drooping of eyelid (ptosis) and weakness of ocular muscles
* decreased reflexes: gag, swallow, pupil reactivity to light
* decreased sensation and muscle weakness of the face
* balance problems and nystagmus
* altered breathing and heart rate
* weakness in sternocleidomastoid muscle (SCM) with inability to turn head to one side
* weakness in tongue (inability to protrude and/or move from side to side)
If the cerebral cortex is involved, the CNS pathways can again be affected, but also can produce the following symptoms:
* aphasia (inability to speak or understand language from involvement of Broca's or Wernicke's area)
* apraxia (altered voluntary movements)
* visual field defect
* memory deficits (involvement of temporal lobe)
* hemineglect (involvement of parietal lobe)
* disorganized thinking, confusion, hypersexual gestures (with involvement of frontal lobe)
If the cerebellum is involved, the patient may have the following:
* trouble walking
* altered movement coordination
* vertigo and or disequilibrium
Loss of consciousness, headache, and vomiting usually occurs more often in hemorrhagic stroke than in thrombosis because of the increased intracranial pressure from the leaking blood compressing on the brain.
If symptoms are maximal at onset, the cause is more likely to be a subarachnoid hemorrhage or an embolic stroke.
Subarachnoid hemorrhage
Main article: subarachnoid hemorrhage
The symptoms of SAH occur abruptly due to the sudden onset of increased intracranial pressure. Often, patients complain of a sudden, extremely severe and widespread headache. The pain may or may not radiate down into neck and legs. Vomiting may occur soon after the onset of headache. Usually the neurologic exam is nonfocal—meaning no deficits can be identified that attributes to certain areas of the brain—unless the bleeding also occurs into the brain. The combination of headache and vomiting is uncommon in ischemic stroke.
Transient ischemic attack (TIA)
Main article: Transient ischemic attack
If the symptoms resolve within an hour, or maximum 24 hours, the diagnosis is transient ischemic attack (TIA), which is in essence a mini or brief stroke. This syndrome may be a warning sign, and a large proportion of patients develop strokes in the future. Recent data indicate that there is about a ten to fifteen percent chance of suffering a stroke in the year following a TIA, with half of that risk manifest in the first month, and, further, with much of that risk manifest in the first 48 hours. The chances of suffering an ischemic stroke can be reduced by using aspirin or related compounds such as clopidogrel, which inhibit platelets from aggregating and forming obstructive clots; but, for the same reason, such treatments (slightly) increase the likelihood and effects of hemorrhagic stroke since they impair clotting.
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Important notice:
The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other
qualified health provider with any questions you may have regarding a medical condition.
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