Sylvian Fissure

The caudal extremity of the sylvian (lateral) fissure may be forked (41%) forming ascending and descending branches. The ascending branch is the most constant and is regarded as the true continuation of the fissure. The ascending branch forms the axis of the supramarginal gyrus.

Triradiate termination of the sylvian fissure has been reported.

According to Cunningham, the anterior rami of the sylvian fissure may assume different configurations: they may be Y-shaped where the two rami, enclosing the triangular frontal gyrus, join the sylvian fissure by a common stem (32% of hemispheres); the two rami may join the sylvian fissure separately, and they may be V- or U-shaped (37% of hemispheres); or a single ramus may join the fissure (30% of hemispheres). Less frequently, there are more than two rami, or the two rami are reduced to one (taking the position of either one of them) or are intermediate in position.

In one study, two rami were observed in 85% of Brains, one ramus in 12%, and three rami in 3%.

The length of the anterior ascending ramus varies from 10 to 30 mm, and of the anterior horizontal, from 10 to 25mm.

The sylvian fissure is frequently longer on the left hemisphere than on the right.

Riferimenti dell’opera originale

Elenco riportato come compare nella fonte, senza normalizzazione dei formati bibliografici.

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