The Geezer’s Dirty Dozen on Catatonia, NMS & Serotonin Syndrome

This Dirty Dozen is about catatonia, neuroleptic malignant syndrome (NMS), and serotonin syndrome. Their clinical features overlap in many ways, and I try to clarify how to distinguish them. I’m indebted to the resources in the reference list below, especially the The Neuroleptic Malignant Information Service.  Up until about a year ago the NMS Information Service (NMSIS) had an 800 number which you could use to call for assistance from internationally recognized experts. That is no longer available, unfortunately. However, there’s a gold mine of educational guidance on the web site and I often use it to stay informed about these syndromes. The service is free and they take donations.

In order to see the picture galleries of photos or powerpoint slides, click on one of the slides, which will open up the presentation to fill the screen. Use the arrow buttons to scroll left and right through the slides or up and down to view the annotations.

References and Web Resources:

Perry, P. J. and C. A. Wilborn (2012). “Serotonin syndrome vs neuroleptic malignant syndrome: A contrast of causes, diagnoses, and management.” Annals of clinical psychiatry : official journal of the American Academy of Clinical Psychiatrists 24(2): 155-162.

BACKGROUND: Serotonin syndrome (SS) and neuroleptic malignant syndrome (NMS) are uncommon but potentially life-threatening adverse reactions associated with psychotropic medications. Polypharmacy and the similar presentation of SS and NMS make diagnosis of the 2 syndromes problematic. METHODS: A MEDLINE search was performed for the period 1960 to 2011 for case reports, review articles, and studies pertaining to SS and NMS. RESULTS: The majority of available literature on SS and NMS consists of case reports, case-control studies, and retrospective reviews. In addition, diagnostic criteria have been developed to aid in the diagnosis and management of SS and NMS. CONCLUSIONS: SS presents as mental status changes, autonomic nervous system disturbances, neurologic manifestations, and hyperthermia. Similarly, NMS presents as muscle rigidity, hyperpyrexia, mental status changes, and autonomic instability. However, the clinical laboratory profile of elevations in creatine kinase, liver function tests (lactate dehydrogenase, aspartate transaminase), and white blood cell count, coupled with a low serum iron level, distinguishes NMS from SS among patients taking neuroleptic and serotonin agonist medications simultaneously. For both SS and NMS, immediate discontinuation of the causative agent is the primary treatment, along with supportive care. For NMS, dantrolene is the most effective evidence-based drug treatment whereas there are no evidence-based drug treatments for SS. A 2-week washout of neuroleptic medication minimizes the chance of recurrence.

Support Services: Neuroleptic Malignant Syndrome Information Service, The Neuroleptic Malignant Information Service where internationally recognized experts provide free educational guidance on diagnosis and management of NMS.

NMS Online Program Overview

Serotonin Syndrome

Neuroleptic malignant syndrome UpToDate

3 thoughts on “The Geezer’s Dirty Dozen on Catatonia, NMS & Serotonin Syndrome

  1. Jim,

    Great work as usual. I agree with you about the NMSIS. That was an amazing service, especially the ability to talk with one of their consultants if you had an acute case. When I scanned your slides I may have missed benzodiazepines as a useful adjunct to both 5HT syndrome and NMS, especially in mild cases or where you are waiting to establish more definitive therapy.

    The other interesting syndrome here is malignant catatonia. Very interesting review on this that I will have to dig out documenting the high prevalence and fatality rate of this disorder in a Boston hospital at the turn of the century. Requires very intensive work supporting the patient while they recover.


    1. Thanks for reminding me about benzodiazepines as an adjunct! I didn’t emphasize that enough. When you find that review, could you get a copy to me somehow?

      I just discussed a case of suspected NMS with Dr. Stanley Caroff recently. He’s quite a guy, erudite and laid back.


      1. That was my experience with Dr. Caroff as well. In these cases it is very useful to be talking with somebody who has seen many of them because our other colleagues at the time often have minimal experience.

        Will try to get you a copy of that reference.


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