Catatonic signs in neuroleptic malignant syndrome

The study assessed catatonic signs in neuroleptic malignant syndrome (NMS). Records of inpatients meeting both stringent research criteria and DSM-IV criteria (n = 11) or only DSM-IV criteria (n = 5) for NMS were identified. The records were systematically rated on a 23-item rating scale for the presence of catatonic signs. Scores for NMS severity were related to the number of catatonic signs. Fifteen patients met both research criteria for catatonia and DSM-IV motor criteria for organic catatonia. The severity scores of NMS correlated with the number of catatonic signs (Spearman rho = +.71, P < .005). We conclude that multiple catatonic signs are present in NMS and the severity of NMS predicts the number of catatonic signs.