Late-onset Tay-Sachs disease presenting as catatonic schizophrenia: diagnostic and treatment issues.

BACKGROUND: It is not commonly appreciated that patients with hexosaminidase A deficiency (Tay-Sachs disease) can first present in adulthood with psychiatric illness.
METHOD: A 17-year-old non-Jewish male patient was referred with a history of treatment-resistant catatonic schizophrenia. We uncovered coexistent neurologic abnormalities and evidence of cognitive decline. Metabolic screening revealed a severe deficiency of beta-hexosaminidase A. We reviewed the literature on late-onset gangliosidosis with attention to (1) the nature of the associated psychiatric and neurologic abnormalities and (2) the treatment of psychosis in these patients.
RESULTS: The patient's catatonia responded promptly to benzodiazepine therapy. Treatment with neuroleptic medication resulted in the rapid development of neuroleptic malignant syndrome. The patient was thereafter maintained on lorazepam with resolution of his acute psychiatric disturbances and unexpected improvement in his neurologic status.
CONCLUSION: Patients with hexosaminidase deficiency may first present in adolescence or adulthood with psychiatric illness, particularly schizophrenic-like psychosis. The presence of speech disturbance, gait abnormalities, movement disorders, and cognitive decline may indicate an underlying metabolic disorder. The use of traditional neuroleptics to treat the psychosis in such individuals may produce an unacceptably high risk/benefit ratio. Benzodiazepines may ameliorate the psychiatric and neurologic abnormalities in these patients.