During the course of an ongoing NIH clinical study evaluating the benefit of cysteamine and N-acetylcysteine in 9 patients with infantile neuronal ceroid lipofuscinosis (INCL), 4 were found to have subdural fluid collections without mass effect. Surgical drainage of fluid revealed evidence of old hemorrhage. Shearing of cortical veins as cerebral atrophy progresses is the mechanism suggested. No trauma or change in symptoms was associated with this finding. At follow-up 2.5 to 7 years later, the fluid collections remained stable or decreased in size. The recognition of this complication of INCL may prevent unnecessary additional investigation and intervention. 
COMMENT. INCL is a neurodegenerative disease caused by mutations in the palmitoyle-protein thioesterase-1 gene (PPT1) and resulting ceroid accumulation. Normal at birth but by 2 years the infant has complete retinal degeneration and blindness followed by seizures and psychomotor deterioration, progressing to a vegetative state by 4 years and by death. Cysteamine and N-acetylcysteine facilitate removal of ceroids from cultured cells in patients with INCL, prompting a bench-to-bedside clinical treatment protocol.