Fatty acid compositions of human brain lecithin and sphingomyelin in normal individuals, senile cerebral cortical atrophy, alzheimer舗s disease, metachromatic leucodystrophy, Tay‐Sachs and Niemann‐Pick diseases

The fatty acid compositions of whole brain lecithin and sphingomyelin were determined. Brain specimens from normal adults, a normal infant, and several disease states were examined. Normal adult brain lecithin has a very simple fatty acid composition (palmitic, stearic, and oleic acids) and infant brain lecithin contains more palmitic acid and less oleic acid than adult brain. The whole brain lecithin fatty acid compositions from metachromatic leucodystrophy, and Tay‐Sachs and Niemann‐Pick diseases are intermediate between that of normal infant and normal adult brain and no characteristic features attributable to specific disease states were detected. The fatty acids of whole brain lecithin from senile cerebral cortical atrophy and Alzheimer舗s disease were similar to normal adult brain except that a greater variety of fatty acids was seen in both pathological states. No characteristic features attributable specifically to either pathological state were detected. The fatty acid composition of normal adult brain sphingomyelin differs from that of the normal infant in that longer chain fatty acids are more abundant in adult brain. The fatty acid compositions of whole brain sphingomyelins from Niemann‐Pick disease and metachromatic leucodystrophy differed from that of normal infant and adult brain in that C24 acids were not detected. No characteristic features attributable to a specific disease were detected. Fatty acid compositions of whole brain sphingomyelins in senile cerebral cortical atrophy and Alzheimer舗s disease were found to be very similar to those of the normal adult.