The Malignant Neuroleptic Syndrome (a Review with Report of Three Cases)

The Malignant Neuroleptic Syndrome (M. N. S.) as a relatively uncommon but potentially lethal complication of neuro-leptic drug treatment was first described in the French literature by Delay el al. (1960), and several cases of so called 'Malig-nant Hyperthermia' in relation to neuro-leptic drug intake were described. It is only in the last few years that this syndrome has received some attention in the English language literature—CarofF (1980) in his review states that a total of about 60 cases have so far been reported in the world literature. Although exact figures of its incidence are difficult to obtain, Delay et al. (1963) in their series of patients treated with haloperidol reported an incidence of approximately 0.5% to 1.0%. This would suggest that M. N. S. is not as rare as generally believed, considering the large number of patients being treated with neuroleptics, but that probably many cases are not recognised as such and hence go unreported. The Malignant Neuroleptic Syndrome is characterised by :— (a) A rise of body temperature—-ranging from 38° C (99°F) to as high as 41°G (106°F). (b) Impairment of Consciousness—which may vary from a dazed mutism through stupor to coma. (c) Autonomic Dysfunction—eg. labile blood pressure with marked tachy-chardia, profuse diaphoresis, dys-pnoea, dysphagia, urinary retention or incontinence. (d) Neuromuscular Dysfunction manifesting as catatonic like rigidity, akinesia, dyskinesia, or involuntary movements. The ligidity is generally described as being of lead pipe or plastic type. Clinical Course : M. N. S. may occur from hours to months after the initial exposure to the drug but once initiated, signs and symptoms develop rapidly over the next 24-72 hours. It usually starts with a sudden, unexplained rise of temperature with impairment of consciousness, followed by the signs of neuromuscular and autonomic dysfunction. It usually lasts from 5 to 10 days after cessation of neuroleptic drug therapy ; and if detected early and intensive supportive therapy instituted, recovery can be expected in a majority of cases. Of the 60 cases described in the literature , death occurred in 12 patients, giving a mortality rate of 20%-Interestingly, 6 of these 12 cases were being treated with depot fluphenazine preparations. Death, when it occurs, is due either to cardio-vascular collapse or respiratory and/ or renal failure. Autopsies performed on these cases have revealed only non-specific or secondary changes. The apparently increased mortality rate with the long acting fluphenazine compounds is probably a function …