fissure of Sylvius vs Sylvian fissure

fissure of Sylvius and Sylvian fissure both are nouns.

Word	Noun	Adjective	Verb	Adverb
fissure of Sylvius	Yes	No	No	No
Sylvian fissure	Yes	No	No	No

As nouns, fissure of Sylvius and Sylvian fissure are synonyms defined as:

fissure of Sylvius and Sylvian fissure: the deepest and most prominent of the cortical fissures; separates the frontal lobes and temporal lobes in both hemispheres

Other synonyms of fissure of Sylvius include lateral cerebral sulcus, sulcus lateralis cerebri.

fissure of Sylvius (noun)	Sylvian fissure (noun)
the deepest and most prominent of the cortical fissures; separates the frontal lobes and temporal lobes in both hemispheres	the deepest and most prominent of the cortical fissures; separates the frontal lobes and temporal lobes in both hemispheres