Hyponatremia, convulsions and neuroleptic malignant syndrome in a male with schizoaffective disorder

Objective: The aim of the study was to highlight the diagnostic difficulties occurring when hyponatremia presents concurrently with neuroleptic malignant syndrome (NMS). Diagnostic issues in the differentiation between hyponatremia and NMS are discussed. Clinical picture: A case of dilutional hyponatremia (DH) secondary to psychogenic polydipsia (PP) associated with NMS occurring in a male with schizoaffective disorder is described. The clinical picture was complicated by convulsions, perhaps due to clonazepam withdrawal and possible lithium toxicity. Treatment: The patient was treated with supportive medical measures. Outcome: The patient made a full recovery. Conclusions: Hyponatremia and NMS have been found to be associated. This association may be due to an undefined common pathogenesis, or may be coincidental. Hyponatremia may also hinder the diagnosis of NMS.