* Progressive CVA, or stroke - in - evolution ( thrombus - in -
evolution ), begins
with slight neurologic deficit and worsens in a day or two.
* Complete CVA, the patient experiences maximal neurologic deficits
at onset.
Most common cause of CVA is a result from thrombosis. Other causes
include
embolism and hemorrhage. Risk factors increase the likelihood
of CVA, such as
atherosclerosis, hypertension, dysrhythmias, rheumatic heart disease, diabetes
mellitus,
gout, postural hypotension, and cardiac hypertrophy. Other risk factors
include high
serum triglyceride levels, and sedentary life - style ( inactive
habit ), the use of
contraceptives, cigarette smoking, and a family history of CVA.
CVA Symptoms:
Clinical features of CVA vary with the artery affected ( and , Consequently,
the portion
of the brain it supplies ), the severity of damage, and the extent of collateral
circulation
that develops to help the brain compensate for decreased blood supply.
If CVA occurs
in the left hemisphere, it produces symptoms on the right side; if in the
right hemisphere,
symptoms are on the left side. However, a CVA that causes cranial
nerve damage
produces signs of cranial nerve dysfunction on the same side as the hemorrhage.
Usually the symptoms are classified according to the artery affected.
It can also be
classified as premonitory, generalized, and focal.
Middle cerebral artery: This type of CVA may cause aphasia ( loss
of the power of
expression of speech, writing, or signs or of comprehending spoken or written
language)
, dysphasia ( impairment of speech), visual field cuts, and hemiparesis
on the affected
side ( more severe in the face and arm than in the leg ).
Carotid artery: The patient may experience weakness, paralysis, numbness,
sensory
changes, visual disturbances on the affected side, altered level of consciousness,
bruits,
headaches, aphasia, and ptosis ( paralytic drooping of the upper eyelid
).
Vertebrobasilar artery: patients may experience weakness on the affected
side,
numbness around the lips and mouth, visual field cuts, diplopia ( the preception
of two
images of a single object ), poor coordination, dysphagia, slurred speech,
dizziness,
amnesia, and failure of muscular coordination (ataxia).
Anterior cerebral artery: This type of stroke can cause confusion,
weakness and
numbness on the affected side ( especially in the leg ), incontinence,
loss of coordination,
impaired motor and sensory functions, and may have personality changes.
Posterior cerebral arteries: Paralysis usually doesn't occur.
Patient may experience
visual field cuts, sensory impairment, dyslexia, coma, and cortical blindness.
Diagnostic tests: CT scan shows evidence of thrombotic or hemorrhagic
stroke, tumor,
or hydrocephalus. Brain scan show ischemic areas but may not be positive
for up to 2
weeks after the CVA. Other tests includes; lumbar puncture, ophthalmoscopy,
angiography, EEG, and lab studies.
Treatment:
Medication useful in CVA include: anticonvulsants to treat seizures,
stool softeners, to
avoid straining, which increases ICP ( intracranial - pressure ), corticosteroids,
to
minimize associated cerebral edema, analgesics to relieve headache that
may follow
hemorrhagic CVA. Usually aspirin is contraindicated in hemorrhagic
CVA because it
increases bleeding tendencies, but it may be useful in preventing TIAs.
Surgery to improve cerebral circulation for patients with thrombotic or
embolic CVA
includes; endarterectomy ( removal of atherosclerotic plaques from inner
arterial wall),
or microvascular bypass ( extracranial vessel is surgically anastomosed
to an
intracranial vessel ).
For More On CVA, See Stroke: (click)
