Signs and Symptoms of a Stroke

About Stroke

A stroke or cerebrovascular accident occurs when the blood supply to the brain is cut off (an ischemic stroke) or when a blood vessel bursts (a hemorrhagic stroke). Most strokes are of the ischemic type. Without oxygen, brain cells begin to die. Death or permanent disability can result. High blood pressure, smoking, and having had a previous stroke or heart attack increase a person’s chances of having a stroke.

Ischemic Stroke

Are all ischemic strokes the same?

There are two types of ischemic strokes.

• Thrombotic strokes are caused by a blood clot (thrombus) in an artery going to the brain. The clot blocks blood flow to part of the brain. Blood clots usually form in arteries damaged by plaque.

• Embolic strokes are caused by a wandering clot (embolus) that’s formed elsewhere (usually in the heart or neck arteries). Clots are carried in the bloodstream and block a blood vessel in or leading to the brain.

How are ischemic strokes diagnosed?

When someone has shown symptoms of a stroke or a TIA (transient ischemic attack), a doctor will gather information and make a diagnosis. He or she will review the events that have occurred and will:

• get a medical history from you or a family member

• do a physical and neurological examination

• have certain laboratory (blood) tests done

• get a CT or MRI scan of the brain

• study the results of other diagnostic tests that might be needed

SYMPTOMS OF STROKE

The symptoms of stroke depend on what part of the brain is affected and how large an area

is involved. A stroke is a sudden event accompanied by one or more of the following signs:

! Numbness or weakness, especially on one side of the body

! Loss of consciousness or altered consciousness

! Decreased vision in one or both eyes

! Language difficulties, either in speaking or understanding

! Difficulty walking; loss of balance or coordination

! Confusion or loss of memory

! Swallowing difficulties

! Paralysis of any body area, including face

! Sudden, severe headache with no known cause

! Neck pain

! Nausea and vomiting

STROKE TESTS
When a patient presents at the emergency room with a suspected stroke, there are several tests available to the doctor to determine the type, location, and severity of the event. Testing depends on the doctor’s assessment of the patient and is done on a case-by-case basis. Available tests include:
! Head CT or head MRI – Used to determine if a stroke has occurred and, if so, what type, i.e., ischemic or hemorrhagic. Can define the location and extent of the stroke and determine if there have been previous strokes.
! Angiography – Radiographic imaging with dye injected directly into an artery. Can show narrowing of the vessel and detect the location and size of aneurysms and vascular malformations.
! Doppler ultrasound/carotid duplex imaging – Use of high-frequency sound waves to detect blockages in the carotid arteries.
! ECG (electrocardiogram) or echocardiogram – may be used to diagnose underlying heart disease or if a cardiac embolus is suspected.

STROKE TREATMENT
Ischemic Stroke
A person coming to the hospital with stroke symptoms will normally be given a CT scan to determine is he or she has had an ischemic or hemorrhagic stroke. If an ischemic stroke is detected, the standard treatment is the intravenous (IV) administration of a clot-busting (thrombolytic) medication such as t-PA (tissue plasminogen activator). T-PA, however, must be administered within three hours of a stroke onset, necessitating that the patient go to the hospital at the first signs of a stroke event. Data from the National Institute of Neurological Disorders and Stroke (NINDS) indicate that patients treated with t-PA within the three-hour window were at least 33% more likely than untreated patients to recover with little or no disability (11). The NINDS study showed that the average length of stay was shorter (10.9 days) for t-PA treated patients than for nontreated patients
(12.4 days); t-PA treated patients were also more likely than others to return home following discharge rather than to a rehabilitation center or nursing home (12). It is estimated, however, that only about
2% of stroke sufferers, however, get to the hospital in time for t-PA therapy and qualify as candidates for t-PA (13).
The most serious risk associated with IV t-PA is bleeding. An estimated 25% of patients will experience some bleeding (14), mostly minor (such as gum or nose bleeding). The NINDS study found that 6.4% of patients suffered bleeding in the brain (15). Other published studies have found both lower percentages and higher percentages of bleeding in the brain, for example, 3.3% in the FDAmandated
Standard Treatment with Alteplase [t-PA] to Reverse Stroke (STARS) Study and 15.7% in a 1997-98 study of two major Cleveland hospitals (15). Because of the risk of bleeding, not all patients can receive t-PA; some of the contraindications include history of intracranial bleeding, major surgery within the past 14 days, serious head trauma, dental extractions within seven days, and pregnancy. Other thrombolytic agents are currently under investigation that might have fewer contraindications than t-PA.

Hemorrhagic Stroke
If a CT or MRI scan has detected bleeding in or around the brain itself, i.e., a hemorrhagic stroke, immediate treatment is also imperative. Both cerebral and subarachnoid hemorrhages can be more deadly than ischemic strokes. The causes of a hemorrhagic stroke include hypertension, a ruptured or leaking aneurysm, a leaking vascular malformation, or anticoagulation medication.
For patients with anticoagulation-induced bleeding, those medications are immediately stopped, and protamine, vitamin K, or fresh frozen plasma may be given to reduce bleeding. Ruptured aneurysms or arteriovenous malformations are generally treated surgically by the use of detachable microcoils or by microsurgical clipping. Microsurgical clipping is the more well-established and longer-used technique. It involves performing a craniotomy, locating the aneurysm and clipping the ase to stop blood from entering the aneurysm. Microcoils use an endovascular technique, during which a catheter is threaded into the affected artery using a cerebral angiogram to guide its path. The catheter contains tiny platinum coils that are released into the aneurysm, inducing clotting to prevent further bleeding. The technique used depends upon the assessment of the patient’s medical team.