Tay-Sachs disease with conspicuous cranial computerized tomographic appearances.

An autopsy case of a 3-year-old female infant with Tay-Sachs disease was presented. A cherry red spot in the fundus and a deficiency of N-acetyl-beta-hexosaminidase A in the white blood cells were revealed soon after admission at the age of one year. Her parents and sister were found to be healthy carriers. The patient showed a typical clinical course with marked cranial swelling. In addition to the marked ballooning of neurons on light microscope, membranous cytoplasmic body (MCB) on electron microscope and abnormal accumulation of GM2 ganglioside in the cerebral cortex by thin layer chromatography were confirmed in the autopsy specimens. In the late stage of her clinical course, the cranial computerized tomography (CT) demonstrated symmetric and deep-wavy hyperdense cerebral cortical zones, diffuse hypodensity and diminished volume of cerebral white matter, mild to moderate ventricular dilatation, and a small cerebellum and brainstem. These conspicuous appearances of the cranial CT seem to be characteristic of Tay-Sachs disease in the late stage, and they are derived from abnormal accumulation of GM2 ganglioside in the cerebral cortex, and diffuse intense demyelination (dysmyelinating demyelination) of the cerebral white matter.