Light and electron microscopic appearance of the inner ear in juvenile ceroid lipofuscinosis (CL).
Inner ear cells were studied by histology, histochemistry and electron microscopy in one case of juvenile form of ceroid lipofuscinosis (Batten's disease). It was found that despite the clinically normal range of auditory acuity (nonaudiometric evaluation) there was a storage process of moderate degree with intralysosomal deposition of a lipopigment of variable ultrastructure with two patterns predominating, curvilinear and fingerprint. Storage was demonstrable in slightly variable degree in every cell type including the receptor cells of the organ of Corti and sensory cells of crista ampullaris. The cochlear neurons displayed a so far unique storage with enormous monovacuolar distension of perikarya comparable only to the lymphocytic vacuolization also present in the juvenile form of the disease. The distension of vacuoles was only partly caused by accumulation of the lipopigment mass and actually led to neuronal deterioration. The results shown here offer a new modell for functional-structural relationship and point to the urgent need of further studies of the inner ear in CL and lysosomal storage generally.