A Case of Lithium-Induced Upper Extremity Peripheral Polyneuropathy and Nephrogenic Diabetes Insipidus

Lithium is the drug of choice for treating bipolar affective disorders. However, it has a narrow therapeutic index and acute and chronic toxicity can occur in patients with chronic ingestion. Chronic toxicity commonly presents as nephrogenic diabetes insipidus or thyroid dysfunction. Neurologic symptoms such as apathy, hyperreflexia, or clonus can also occur in acute toxicity. However, it rarely causes peripheral neuropathy. We experienced a case of lithium-induced peripheral polyneuropathy who had already nephrogenic diabetes insipidus and chronic kidney disease during 25 years of lithium ingestion due to bipolar disorder.