Stroke symptoms and diagnosis

Patient information: Stroke symptoms and diagnosis

Author
Louis R Caplan, MD
Section Editor
Scott E Kasner, MD
Deputy Editor
John F Dashe, MD, PhD

Disclosures

STROKE OVERVIEW — Stroke is the term doctors use when a part of the brain dies because it goes without blood for too long. There are two main types of stroke: those caused by a blockage in a blood vessel in the brain, and those caused by bleeding in the brain or surrounding area. (See “Etiology and classification of stroke”.)

In the United States, approximately 700,000 strokes happen each year, most of which are caused by a blockage in a blood vessel. Strokes can cause long-lasting disability or even death. However, early treatment and preventive measures can reduce the brain damage that occurs because of stroke.

The symptoms of a stroke may begin suddenly or develop over hours or days, depending upon the type of stroke. In both types of stroke, one or more areas of the brain can be damaged. Depending upon the area affected, a person may lose the ability to move one side of the body, the ability to speak, or a number of other functions.

The damage from a stroke may be temporary or permanent. A person’s long term outcome depends upon how much of the brain is damaged, how quickly treatment begins, and several other factors.

TYPES OF STROKE — There are two main types of stroke:

Ischemic stroke — Ischemic strokes are caused by a blockage (clog) in one of the blood vessels that supply oxygen and other important nutrients to the brain. If the artery remains blocked for more than a few minutes, and enough blood can’t get through, the brain can become damaged. The majority of strokes are ischemic.

There are two main subtypes of ischemic stroke, thrombotic and embolic.

Thrombotic stroke — A thrombotic stroke results from a problem within an artery (blood vessel) that supplies blood to the brain. This is most likely to occur in arteries that are clogged with fatty deposits, called plaques. Plaques partially block the artery, and can rupture and bleed, forming a blood clot. This blood clot (“thrombus”) can further clog or completely block the artery, which then slows or prevents blood flow to the area of brain fed by that artery.

Embolic stroke — An embolic stroke occurs when a blood clot or other particle travels from another part of the body (often the heart) through the bloodstream to the brain where it lodges in a smaller blood vessel. The blood clot or particle, called an “embolus,” then blocks blood flow to that area of the brain, reducing the amount of oxygen and nutrients that reach that area. One of the most common causes of embolic strokes is an irregular heart rhythm called “atrial fibrillation.” Blood clotting disorders can also cause embolic stroke in some people. (See “Patient information: Atrial fibrillation” and “Patient information: The antiphospholipid syndrome”.)

Transient ischemic attack (TIA) — Transient ischemic attacks are episodes in which a person has signs or symptoms of a stroke (eg, numbness; inability to speak) that last for a short time, but without any sign of stroke on brain scans such as MRI or CT. Symptoms of a TIA usually last between a few minutes and a few hours. A person may have one or many TIAs. People recover completely from the symptoms of a TIA.

A TIA is a warning sign that a person is at high risk for a stroke; immediate treatment can decrease or eliminate this risk. It is important to get help right away if you think you may be having a TIA or a stroke.

Hemorrhagic stroke — Hemorrhagic strokes occur when blood vessels in the brain leak or rupture (break), causing bleeding in or around the brain. “Hemorrhage” is the medical term for bleeding. This can lead to pressure within the head, which can cause damage to the brain. Also, blood is irritating to the brain tissue, and can cause it to swell.

There are two main subtypes of hemorrhagic stroke, intracerebral and subarachnoid.

Intracerebral hemorrhage — In an intracerebral hemorrhage (ICH), bleeding occurs within the brain. This damages the brain as blood collects and puts pressure on the surrounding tissue. Some common causes of ICH include:

high blood pressure
injury
bleeding disorders
deformities in blood vessels, such as an aneurysm (a weakening in the lining of the blood vessel)
Subarachnoid hemorrhage — Subarachnoid hemorrhage occurs when a blood vessel on the surface of the brain ruptures. The blood builds up and causes pressure in the “subarachnoid” space, which is between two layers of the tissue covering the brain. The most common symptom of a subarachnoid hemorrhage is a severe headache called “thunderclap headache,” which many patients describe as the worst headache of their life. (See “Patient information: Headache causes and diagnosis in adults”.)

STROKE RISK FACTORS — There are a number of risk factors for stroke; some of these factors increase the risk of one type of stroke (hemorrhagic or ischemic), while others increase the risk of both types.

Ischemic stroke risk factors

Age older than 40 years
Heart disease
High blood pressure
Smoking
Diabetes
High blood cholesterol levels
Illegal drug use
Recent childbirth
Previous history of transient ischemic attack
Inactive lifestyle and lack of exercise
Obesity
Current or past history of blood clots
Hemorrhagic stroke risk factors

High blood pressure
Smoking
Illegal drug use (especially cocaine and “crystal meth”)
Use of warfarin or other blood thinning medicines
Risk factors can increase the risk of stroke, but strokes can happen in people who don’t know that they are at risk. In some cases, the stroke may be due to problems with the blood vessels in the brain or the blood itself. For example:

A hemorrhagic stroke can occur if a person has an aneurysm (a weakness in a blood vessel wall), even if this has never caused symptoms in the past.
An ischemic stroke may occur in a healthy person who takes certain medications (for example, estrogen replacement therapy increases the risk of blood clots).
Occasionally, strokes occur in people who have no risk factors.

STROKE SYMPTOMS — Signs and symptoms of stroke often develop suddenly and then may temporarily improve or slowly worsen, depending upon the type of stroke and area of the brain affected.

Classic symptoms — Knowing the signs and symptoms of a stroke can be lifesaving. Classic stroke symptoms can be recalled with the acronym FAST (figure 1). Each letter in the word stands for one of the things you should watch for:

Face — Sudden weakness or droopiness of the face, or problems with vision
Arm — Sudden weakness or numbness of one or both arms
Speech — Difficulty speaking, slurred speech, or garbled speech
Time — Time is very important in stroke treatment. The sooner treatment begins, the better the chances are for recovery.
Signs and symptoms of a stroke may be similar to other conditions; the only way to know for sure is to be seen as soon as possible by an experienced doctor or nurse.

When to call for emergency medical assistance — A stroke is a medical emergency. If you think you or someone around you may be having a stroke, call 9-1-1 immediately. Do not try to drive yourself to the hospital. (See “Initial assessment and management of acute stroke”.)

Emergency medical services (EMS) workers will respond as quickly as possible, and will take you to a hospital that can care for people during and after a stroke. For a person having a stroke, every minute is important. It is important to call 9-1-1 in this situation because:

From the moment EMS workers arrive, they can begin evaluating and treating you. If you drive yourself to the hospital or have someone else drive you, treatment cannot begin until after you arrive in the emergency department.
If a dangerous complication of a stroke (eg, a seizure or loss of consciousness) occurs on the way to the hospital, EMS workers may be able to treat the problem immediately.
STROKE DIAGNOSIS — Anyone who has signs or symptoms of a stroke needs immediate medical attention in an emergency department or hospital. Most clinics and medical offices do not have the ability to perform the tests needed to diagnose stroke, or the ability to provide the specialized treatment(s) needed to limit damage to the brain. (See “Overview of the evaluation of stroke”.)

Blood tests and brain imaging — After doing a physical exam and reviewing the patient’s history, the doctor or nurse usually orders blood tests and an imaging test (eg, CT scan or MRI) of the brain and the surrounding blood vessels in the neck and head that supply the brain with blood. The imaging allows the doctor or nurse to see the area of the brain affected by the stroke, as well as to confirm the type of stroke (ischemic or hemorrhagic). Other tests may be done as well.

Occasionally, a catheter must be inserted through a blood vessel in the groin and threaded up to the blood vessels of the neck, where dye is injected to highlight any areas of blockage.

Heart testing — An electrocardiogram (ECG) is performed in most people who are thought to be having a stroke. Because many people with ischemic strokes also have coronary artery disease, there may be a lack of blood flow (called “ischemia”) in the heart during the stroke. In some cases, the person may not be able to tell the clinician that he or she feels chest pain. The ECG will help the clinician to diagnose and treat any heart problems as quickly as possible.

Other heart testing may also be recommended, such as an echocardiogram. This test uses sound waves to examine the heart and the aorta (the main artery that supplies the whole body). In some people with embolic strokes, the heart or the aorta is the source of the blood clot that led to the stroke.

STROKE TREATMENT — The treatment of a stroke depends upon the type of stroke, the time that has passed since the first symptoms occurred, and the patient’s other medical problems. Information about treatment is provided separately. (See “Patient information: Hemorrhagic stroke treatment” and “Patient information: Ischemic stroke treatment”.)

OUTCOME AFTER STROKE — The effects of a stroke can be temporary or permanent, and a person may lose function partially or completely. The medical team caring for the patient can give guidance to family members regarding the risk of long term disability or death. However, the outcome can vary greatly from person to person, and it is not always possible to predict what will happen.

WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient Level Information:

Patient information: Atrial fibrillation
Patient information: The antiphospholipid syndrome
Patient information: Headache causes and diagnosis in adults
Patient information: Hemorrhagic stroke treatment
Patient information: Ischemic stroke treatment

Professional Level Information:

Antiplatelet therapy for secondary prevention of stroke
Antithrombotic therapy to prevent embolization in nonvalvular atrial fibrillation
Cardiac complications of stroke
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)
Cerebrovascular disorders complicating pregnancy
Clinical diagnosis of stroke subtypes
Cryptogenic stroke
Decompressive hemicraniectomy for malignant middle cerebral artery territory infarction
Definition of transient ischemic attack
Differential diagnosis of brain ischemia
Etiology and classification of stroke
Etiology, clinical features, and diagnosis of cerebral venous thrombosis
Etiology, clinical manifestations, and diagnosis of aneurysmal subarachnoid hemorrhage
Reperfusion therapy for acute ischemic stroke
Headache, migraine, and stroke
Initial assessment and management of acute stroke
Initial evaluation and management of transient ischemic attack and minor stroke
Intracranial large artery atherosclerosis
Lacunar infarcts
Medical complications of stroke
Neuroimaging of acute ischemic stroke
Overview of the evaluation of stroke
Posterior circulation cerebrovascular syndromes
Secondary prevention for specific causes of ischemic stroke and transient ischemic attack
Secondary prevention of stroke: Risk factor reduction
Spontaneous intracerebral hemorrhage: Pathogenesis, clinical features, and diagnosis
Spontaneous intracerebral hemorrhage: Prognosis and treatment
Treatment of aneurysmal subarachnoid hemorrhage

The following organizations also provide reliable health information.

National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)

National Institute of Neurological Disorders and Stroke
(www.ninds.nih.gov/disorders/stroke/stroke.htm)

American Stroke Association
(www.strokeassociation.org)

REFERENCES
Adams RJ, Chimowitz MI, Alpert JS, et al. Coronary risk evaluation in patients with transient ischemic attack and ischemic stroke: a scientific statement for healthcare professionals from the Stroke Council and the Council on Clinical Cardiology of the American Heart Association/American Stroke Association. Stroke 2003; 34:2310.
Adams HP Jr, del Zoppo G, Alberts MJ, et al. Guidelines for the early management of adults with ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council, Clinical Cardiology Council, Cardiovascular Radiology and Intervention Council, and the Atherosclerotic Peripheral Vascular Disease and Quality of Care Outcomes in Research Interdisciplinary Working Groups: the American Academy of Neurology affirms the value of this guideline as an educational tool for neurologists. Stroke 2007; 38:1655.
Sandercock P, Gubitz G, Foley P, Counsell C. Antiplatelet therapy for acute ischaemic stroke. Cochrane Database Syst Rev 2003; :CD000029.
Caplan, LR. Stroke (American Academy of Neurology Press Quality of Life Guide Series), Demos Medical, New York 2006.