ACHROMATIC NEURONS IN THE CORTEX OF PROGRESSIVE SUPRANUCLEAR PALSY

Achromatic neurons (AN) in the cerebral cortex are a characteristic fe ature of several neurodegenerative conditions including Pick's disease , corticobasal degeneration and some cases of primary progressive apha sia. Although AN are occasionally seen in some other diseases, their p resence in progressive supranuclear palsy (PSP) has not been previousl y documented. We found significant numbers of AN in the cerebral corte x of five out of seven cases which had been diagnosed pathologically a s PSP The identification of AN was greatly facilitated by the use of n eurofilament immunohistochemistry. The entorhinal and transentorhinal cortices were most frequently involved, but in several cases AN were a lso seen throughout the neocortex. The presence and number of AN rough ly correlated with a history of clinical dementia. This suggests that cortical AN may be a common and important pathological finding in PSP.