IN the difficult and diagnostic problem case of poorly localized Central-nervous-system disease a low concentration or absence of sugar in the spinal fluid may indicate neoplastic infiltration of the leptomeninges. Little attention to this helpful clinical finding has been paid in the medical literature for some time. The purpose of this communication is to present a case demonstrating hypoglycorrhachia in an effort to give further emphasis to this clinical syndrome. Case Report A 47-year-old man was admitted to the hospital on January 22, 1962, for treatment of recent psychotic-type behavior. On admission he demonstrated a bizarre mental picture, mild residual . . .