For proper neurologic function of the brain, sufficient blood supply is needed. When blood supply to a part of the brain is stopped suddenly, stroke results and neurologic function gets impaired.
There are two types of strokes - hemorrhagic and ischemic.
Ischemic stroke, the more common of the two, is an acute condition caused by thrombosis or embolism.
Signs and symptoms of Ischemic stroke
Here are some signs and symptoms of Ischemic stroke. These may show up separately or in combination with each other.
• Hemiparesis (weakness on one side), monoparesis (weakness of one leg or arm), or quadriparesis (weakness in all four limbs)
• Sudden partial sensory loss
• Hemianopia (Complete or partial), diplopia or loss of vision (monocular or binocular)
• Visual field deficits
• Declining consciousness
If the patient is relatively young, the doctor will check with him or her if there was a history of trauma, migraine, coagulopathies, drug abuse (mostly cocaine) or use of oral contraceptives.
Thrombolytic therapy helps the doctor assess the neurologic condition of the suspected stroke patient quickly. The neurologic examination involves checking the following:
• Condition of cranial nerves
• Sensory system
• Functioning of the Cerebellum
• Mental status
• Motor function
• The movement pattern of limbs
• Reflexes of tendons
• Level of consciousness
The doctor will also check the skull and spine of the patient. He will also look for signs of meningismus.
The following lab tests are used to evaluate ischemic stroke:
• Total count of blood cells: The complete blood count might reveal a cause for the stroke (eg, thrombocytopenia, thrombocytosis, leukemia, polycythemia)
• Bio chemistry: The chemistry panel might help find stroke mimics such as hypoglycemia or hyponatremia, or even give proof of disorders such as diabetes or renal insufficiency.
• Coagulation tests: Coagulation studies come in handy when thrombolytics or anticoagulants are to be used. It might even reveal a coagulopathy.
• Cardiac markers: If the patient suffers from cerebral vascular disease or coronary artery disease, cardiac markers will be helpful.
• Screening for toxins: This will help ascertain if the patient is intoxicated. Intoxicated patients sometimes show symptoms of stroke.
The following imaging techniques are used to diagnose ischemic stroke:
• Computed tomography (CT) scanning
• Magnetic resonance imaging (MRI)
• Nuclear imaging
Sometimes the CT scan may be negative, but still the doctor suspects something is wrong with the brain. Lumbar puncture helps rule out meningitis or subarachnoid hemorrhage when the CT scan is negative.
Managing Ischemic stroke involves the following:
• Thrombolytic therapy: This therapy improves the blood flow to cerebrum in some patients; and may help improve the overall neurologic condition.
• Antiplatelet agents: Medications like aspirin might be useful for stroke patients.
• Mechanical thrombolysis: Some patients with acute ischemic stroke will be given endovascular treatment.
• Test for pregnancy: If the stroke patient is a woman who is likely to bear a child, a urine pregnancy test should be obtained. Recombinant tissue-type plasminogen activator (rt-PA) is a pregnancy class C agent.
• Arterial blood gas analysis: This test is used to find out acid-base disturbances inside the arteries in patients with suspected hypoxemia. The severity of the disease can be found out through this test.
For patients who are likely to suffer from stroke in future, the following stroke-preventing measures may prove useful.
• Platelet antiaggregants
• 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (ie, statins)
Those who have already had a stroke may use the following:
• Platelet antiaggregants
• HMG-CoA reductase inhibitors (statins)
Change in lifestyle might also help reduce the risk of future stroke.
Dr. Sanjiv C.C is a senior neurologist who is an expert in Parkinsons diagnosis and management. He is available for consultation in the city of Bangalore at Apollo Hospital, Jayanagar.