Leptomeningeal collateral circulation
Encyclopedia
The term leptomeningeal refers to the two deep layers of the meninges — the pia mater
and the arachnoid mater
. The leptomeningeal collateral circulation is a network of blood vessels supplying the brain that follows a diffuse course over the superficial surface of the brain.
is occluded during a CVA (or stroke
), there is dramatic loss of blood flow to the area of the brain supplied by this artery (the lateral surfaces of the frontal, parietal and temporal lobes, including the primary motor and sensory cortexes). The leptomeningeal collateral circulation allows a very limited degree of compensation for this. However, this mild compensatory effect is nowhere near adequate - a CVA is a very serious medical emergency.
Pia mater
Pia mater often referred to as simply the pia, is the delicate innermost layer of the meninges, the membranes surrounding the brain and spinal cord. The word finds its roots in Latin, meaning literally "tender mother." The other two meningeal membranes are the dura mater and the arachnoid mater....
and the arachnoid mater
Arachnoid mater
The arachnoid mater, literally from Latin "spider -like mother", is one of the three meninges, the membranes that cover the brain and spinal cord...
. The leptomeningeal collateral circulation is a network of blood vessels supplying the brain that follows a diffuse course over the superficial surface of the brain.
Leptomeningeal Collateral Circulation and Cerebrovascular Accidents
If the middle cerebral arteryMiddle cerebral artery
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is occluded during a CVA (or stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
), there is dramatic loss of blood flow to the area of the brain supplied by this artery (the lateral surfaces of the frontal, parietal and temporal lobes, including the primary motor and sensory cortexes). The leptomeningeal collateral circulation allows a very limited degree of compensation for this. However, this mild compensatory effect is nowhere near adequate - a CVA is a very serious medical emergency.