Catatonia Associated with Hyponatremia: Case Report and Brief Review of the Literature

BACKGROUND: Catatonia is a syndrome of altered motor behavior that is mostly associated with general medical, neurologic, mood and schizophrenia-spectrum disorders. The association of newly onset catatonic symptoms with hyponatremia has been rarely reported in the literature. CASE PRESENTATION: We present a rare case of a young female patient with schizophrenia, who presented with catatonic symptoms in the context of hyponatremia due to water intoxication. The symptoms were eliminated with the correction of hyponatremia. There are only a few reports of hyponatremia-associated catatonia in psychiatric and non-psychiatric patients. Sometimes, catatonic symptoms may co-occur with newly onset psychotic symptoms and confusion, suggesting delirium. In several cases, the catatonic symptoms responded to specific treatment with benzodiazepines or electroconvulsive therapy. CONCLUSION: Hyponatremia may induce catatonic symptoms in patients, regardless of underlying mental illness, but this phenomenon is even more relevant in patients with a psychotic or mood disorder, which may itself cause catatonic symptoms. It is important for clinicians not to attribute newly-onset catatonic symptoms to the underlying psychotic or mood disorder without measuring sodium serum levels. The measurement of sodium serum levels may guide treating psychiatrists to refer the patient for further investigation and appropriate treatment.