Archive for the ‘Lacunar Infarction’ Category
An infarction is a portion of tissue that has died turning into a hardened whitish mass. An infarction can happen in many places. A lacunar infarction takes place in the brain and is also called a lacunar stroke. ‘Lacunes’ is a Latin word for “empty space”. C. M. Fisher used this word to describe the empty spaces he found deep inside post postmortem brain structures of people who had suffered a stroke while alive.
A lacunar stroke happens when a deep artery in the brain becomes closed off, or occlused. This is a particular artery that comes out of a portion of these arteries; the Circle of Willis, the basilar artery, and the cerebellar arteries.
The occlusion causes lesions deep in specific areas of the brain. Lesions are wounds or injuries. The lesions that happen as a result of a lacunar stroke occur in the putamen, the thalamus, the caudate, the pons and the anterior (front) limb of the internal capsule.
There are certain risk factors that increase the risk of a lacunar infarction. They include:
high blood pressure that continues for long periods of time
reaching an older age
There are some factors that are thought to causal, but studies have not yet confirmed them. These include:
history of having a stroke
The signs or symptoms of a lacunar infarction can be non-existent. The infarction is then called “a silent lacunar stroke”. A silent lacunar infarction is often not as detectable as one from which a person has developed symptoms. Silent strokes, including lunar infarctions often cause lesions that are only detectable via an MRI, a CT scan, or a similar neuroimaging technique. The silent strokes are more common that was once thought. Up to eleven million happen in the United States annually without showing signs or symptoms. Only about 10% of these silent strokes are lacunar strokes.
When a stroke is not labeled silent, it is because one of the five classic symptoms and signs have become obvious. These signs and symptoms can show up intermittently, fluctuating in their verocity. They can also occur suddenly full force, or start progessively and get worse with time. The five common symptoms ,also called syndromes, are as follows:
1. Pure motor stroke/hemiparesis – This infarction will present symptoms like hemiparesis or hemiplagia of a leg, an arm, or a side of the face. Hemiparesis is a weakness of these muscles, while a hemiplegia is a complete loss of strength in these structures. This symptom is caused by an infarction of the posterior limb of the internal capsule, corona radiata, or basis pontis.
2. Ataxic hemiparesis – Caused by an infarct in the same regions as the above symptom, as well as the red nucleus or lentiform nucleus, this symptom causes a weakness of the arm or leg occurring over a period of hours or days.
3. Dysarthria – also called the ‘clumsy hand’, this sign of a lacunar stroke is displayed by a weakness of the hand. This is usually shown first when the patient attempts to make a signature.
4. Pure Sensory Stroke – This symptom is indicated by a transient or persistent numbness, burning, tingling, pain, or any other sensation that happens on just one side of the body and is not pleasant.
5. Mixed sensorimotor stroke – this lacunar symptom causes not only a weakness or loss of muscle control, but can also cause the impairing of the senses on one side of the body as well.
The prognosis for most people who suffer a lacunar stroke is positive. Most people survive.