Watershed Stroke

The stroke or cerebrovascular accident involves a rapid loss of the brain function due to the interruption in the blood supply to complete or some portion of the brain. It is caused due to hemorrhage, thrombosis or embolism. The stroke can cause a permanent neurological damage or even results in death if it is not properly treated. Different types of strokes are ischemic stroke, hemorrhagic stroke, embolic stroke, watershed stroke and rarer types of stroke.

The watershed stoke is also called as the systemic hypoperfusion. It features the decrease in the blood flow in all body parts. The watershed stroke is a type of stroke that affects the areas of brain from the direct perfusion with the blood supply. The watershed strokes are caused by severe atherosclerosis of the carotid arteries, systemic hypotension/shock or the congestive heart failure.

The most common reasons for the systemic hypoperfusion are the cardiac pump failure due to cardiac arrest or arrhythmias, reduced cardiac output due to the pulmonary embolism, bleeding, myocardial infarction or pericardial effusion. Hypoxemia/low blood oxygen content is also responsible for the watershed stroke.

The circulation in the brain is provided by the small end-arteries arising from the larger central blood vessels. The poor perfusion of the brain strongly affects the tissues supplied by the most distal branches of these small arteries. It leads to infarction and ischemia at the edges of these watershed areas. The watershed stroke in the overlapped distribution region between the middle cerebral artery and the anterior cerebral artery causes the weakness of the proximal arm and the leg muscles. It causes the preservation of the distal strength. This happens because such muscles are controlled by the particular region of the brain.

The brain has three prominent central nervous system pathways such as dorsal column, corticospinal tract and spinothalamic tract. If the area of the brain containing one of these pathways is damaged, then the symptoms include numbness, muscle weakness and reduction in the sensory or vibratory sensation. If the brainstem is affected, the symptoms are altered vision, taste, smell or hearing, decreased reflexes, muscle weakness and reduced sensation, weakness of tongue balance problems and altered heart rate and breathing.

The diagnosis can be done by a neurological examination, MRI scan, CT scans, blood tests, Doppler ultrasound and arteriography.

Recommended Reading

1. Types Of Stroke - The stroke is a sudden interruption or reduction in the blood supply to the brain. The most common reasons of...
2. Signs Of Stroke - The stroke is a condition of body caused due to interrupted or severely reduced blood supply to the part of...
3. Symptoms Of Stroke - Symptoms of stroke are sudden numbness or weakness of the face, arm or leg, sudden confusion, trouble speaking or understanding...
4. Migraine And Stroke - The connection of migraine and stroke is a double bind for the neurologists. Migraine is closely connected with a greater...
5. Thrombotic Stroke - Thrombotic strokes are the strokes that are generally caused by a thrombus or a blood clot. This thrombus or the...