Neuroleptic Malignant Syndrome Evidence from Database Studies

Neuroleptic Malignant Syndrome Evidence from Database Studies

Evidence from database studies suggests incidence rates for neuroleptic malignant syndrome of 0.01%–0.02% among individuals treated with antipsychotics(Spivak et al. 2000; Stübner et al. 2004). The temporal progression of signs and symptoms provides important clues to the diagnosis and prognosis of neuroleptic malignant syndrome. Alteration in mental status and other neurological signs typically precede systemic signs(Velamoor et al. 1994). The onset of symptoms varies from hours to days after drug initiation. Some cases develop within 24 hours after drug initiation, most within the first week, and virtually all cases within 30 days(Caroff and Mann 1988). Once the syndrome is diagnosed and oral antipsychotic drugs are discontinued, neuroleptic malignant syndrome is self-limited in most cases. The mean recovery time after drug discontinuation is 7–10 days, with most individuals recovering within 1 week and nearly all within 30 days(Caroff and Mann 1988). The duration may be prolonged when long-acting antipsychotics are implicated. There have been reports of individuals in whom residual neurological signs persisted for weeks after the acute hypermetabolic symptoms resolved(Caroff et al. 2000). Total resolution of symptoms can be obtained in most cases of neuroleptic malignant syndrome; however, fatality rates of 10%–20% have been reported when the disorder is not recognized(Caroff 2003). Although many individuals do not experience a recurrence of neuroleptic malignant syndrome when rechallenged with antipsychotic medication(Pope et al. 1991), some do, especially when antipsychotics are reinstituted soon after an episode(Caroff and Mann 1988; Rosebush et al. 1989Susman and Addonizio 1988).