Permanent neurological sequelae due to lithium toxicity D. Nagaraja*, A.B. Taly*, R.N. Sahu* *, S.M. Channabasavanna* *, and H.S. Narayanan* * Introduction Over the past two decades lithium has widely been used in clinical practice and has been the sheet anchor of treatment for recurrent manic depressive illness.1 Acute neurological compli- cations with lithium intoxication and minor tran- sient reversible neurological symptoms during maintenance therapy with lithium are common.2 However, permanent neurological sequelae are rare. 3-8 Six patients who developed irreversible neuro- logical deficits, while on lithium therapy, are re- ported. Detailed clinical, radiological and electrophysiological findings are discussed. Materials and methods Over a period of 10 years, 956 patients of manic depressive illness were prescribed lithium carbo- nate at the National Institute of Mental Health & Neuro Sciences, Bangalore. Among the 488 pa- tients on continuous lithium with regular follow- up,six cases were observed to have permanent neurological sequelae. Detailed history with special reference to precipitating factors was ob- tained from the patients and their relatives. A thorough clinical assessment for neurologic defi- cit was made. Routine analysis of blood, urine and cerebro-spinal fluid was performed. Elec- troencephalogram, visual and brain stem evoked Summary Lithium intoxication is well known to produce acute and chronic symptoms but development of permanent neurological deficit is a rarity. Six cases of manic depressive psychosis who developed neurological sequelae following treatment with lithium carbonate are de- scribed. There were multiple lesions in the central nervous system. However, the main brunt was borne by cerebellum. The serum lithium levels of five patients were within therapeutic range. The value of identifying the precipitating factors, early diagnosis and prompt intervention in the prevention of per- sistent neurological dysfunction is emphasized. Key words: Lithium carbonate, intoxication, neurological sequelae. potentials, nerve conduction studies and CT scan were carried out. Patients were followed up for a period ranging from 10 months to 10 years. Results All the six cases were suffering from manic de- pressive psychosis. Their age ranged between 32 to 56 years. There were four men and two wo- men. Detailed neurological assessment prior to Departments of* Neurology and* * Psychiatry, National Institute of Mental Health and Neuro sciences, Bangalore- 560 029, India Address for correspondence and reprint requests: D. Nagaraja, Department of Neurology, National Institute of Mental Health & Neuro Sciences, Bangalore - 560 029, India Accepted 11.8.86 Clin Neurol Neurosurg 1987. Vol. 89-1 31