Ischemic Stroke (Clots)
According to American Stroke Association:
Occurs when a blood vessel supplying blood to the brain is obstructed. It accounts for 87 percent of all strokes. The underlying condition for this type of obstruction is the development of fatty deposits lining the vessel walls. This condition is called atherosclerosis.
Fatty deposits lining the vessel walls, called atherosclerosis, are the main cause for ischemic stroke. Fatty deposits can cause two types of obstruction:
- Cerebral thrombosis is a thrombus (blood clot) that develops at the fatty plaque within the blood vessel.
- Cerebral embolism is a blood clot that forms at another location in the circulatory system, usually the heart and large arteries of the upper chest and neck. Part of the blood clot breaks loose, enters the bloodstream and travels through the brain’s blood vessels until it reaches vessels too small to let it pass. A main cause of embolism is an irregular heartbeat called atrial fibrillation. It can cause clots to form in the heart, dislodge and travel to the brain.
Hemorrhagic strokes make up about 13 percent of stroke cases. It’s caused by a weakened vessel that ruptures and bleeds into the surrounding brain. The blood accumulates and compresses the surrounding brain tissue.
The two types of hemorrhagic strokes are intracerebral (within the brain) hemorrhage or subarachnoid hemorrhage.
TIA (Transient Ischemic Attack)
Called a “mini stroke,” it’s caused by a serious temporary clot. This is a warning stroke and should be taken seriously.
A Transient Ischemic Attack (TIA) is often called a mini-stroke, but it’s really a major warning.
TIA is a temporary blockage of blood flow to the brain. Since it doesn’t cause permanent damage, it’s often ignored. But this is a big mistake. TIAs may signal a full-blown stroke ahead.
In most cases, a stroke is caused by a blood clot that blocks the flow of blood to the brain. In some instances, despite testing, the cause of a stroke cannot be determined. A stroke of unknown cause is called a “cryptogenic stroke.”
That’s why it’s important to dig deeper for a definitive diagnosis. Collaboration by neurologists, cardiologists, electrophysiologists and others may reveal the answers needed to provide targeted treatment for preventing recurrent strokes.
Brain Stem Stroke
Brain stem strokes can have complex symptoms, and they can be difficult to diagnose. A person may have vertigo, dizziness and severe imbalance without the hallmark of most strokes — weakness on one side of the body. The symptoms of vertigo dizziness or imbalance usually occur together; dizziness alone is not a sign of stroke. A brain stem stroke can also cause double vision, slurred speech and decreased level of consciousness.
Only a half-inch in diameter, the brain stem controls all basic activities of the central nervous system: consciousness, blood pressure and breathing. All motor control for the body flows through it. Brain stem strokes can impair any or all of these functions. More severe brain stem strokes can cause locked-in syndrome, a condition in which survivors can move only their eyes.
If a stroke in the brain stem results from a clot, the faster blood flow can be restored, the better the chances for recovery. Patients should receive treatment as soon as possible for the best recovery.
Like all strokes, brain stem strokes produce a wide spectrum of deficits and recovery. Whether a survivor has minor or severe deficits depends on the location of the stroke within the brain stem, the extent of injury and how quickly treatment is provided.
Risk factors for brain stem stroke are the same as for strokes in other areas of the brain: high blood pressure, diabetes, heart disease, atrial fibrillation and smoking. Similarly, brain stem strokes can be caused by a clot or a hemorrhage. There are also rare causes, like injury to an artery due to sudden head or neck movements.
Recovery is possible. Because brain stem strokes do not usually affect language ability, the patient is often able to participate more fully in rehabilitation therapy. Double vision and vertigo usually resolve after several weeks of recovery in mild to moderate brain stem strokes.