Opsoclonus-myoclonus syndrome (OMS) is an autoimmune disorder of the brain triggered by neuroblastoma and certain viral infections (1,7).  It causes serious problems with balance, behavior, and learning (10).  Without immunotherapy, the brain injury can become permanent, leading to attention-deficit disorder, persistent motor problems, and mental retardation (14).

Adrenocorticotrophic hormone (ACTH) is the “gold standard” for the treatment of OMS because it has the greatest capacity for inducing a neurological remission (9). Studies have shown that ACTH exerts multiple beneficial effects on the brain and the immune system (8).

ACTH is available as Acthar gel (80 IU/cc).  Beginning with high doses (150 IU/m2), which are initially injected twice a day for one week, then daily for one week, ACTH is tapered over 40-52 weeks.  For most of the course, however, it is given on alternate days.  Efficacy of high-dose ACTH in OMS has been documented by blinded-scoring of before-and-after videotapes.  All patients improved by 50-70% (11).

ACTH was first used for OMS in 1962 by Dr. Kinsbourne (4), who described the syndrome.  Since then, there have many reports of its effectiveness in the medical literature (2,3,5,6,12).  ACTH is the standard of practice among child neurologists for the treatment of OMS (13,14).  It is not experimental.

In children with moderate or severe OMS, there is no practical alternative to ACTH.  Steroids are associated with partial responses or lack of response (14).  IVIg is also not as effective, and is best used as adjunctive therapy (9).  At the National Pediatric Myoclonus Center, we routinely evaluate steroid-failures.  It is gratifying that most can be put into remission by changing them to ACTH.  The reverse is never true.

References:

1. Bray PF, Ziter FA, Lahey ME, Myers CG. The coincidence of neuroblastoma and acute cerebellar encephalopathy. Journal of Pediatrics 75:983-990, 1969.
   
   
2. Corrias A, Nurchi AM, Rossi G, Sorcinelli R, Pusceddu G, Corda R. Opsoclonic encephalopathy in childhood (Kinsbourne syndrome). Pediatr Med Chir 1985;7:437-41.
   
   
3. Cottom DG. Acute cerebellar ataxia. Arch Dis Child 1957;32:181-8.
   
   
4. Kinsbourne M. Myoclonic encephalopathy of infants. Journal of Neurology, Neurosurgery, Psychiatry 25:271-276, 1962
   
   
5. Klingman WO, Hodges FG. Acute ataxia of unknown origin in childhood. J Pediatr 1944;24:536-43.
   
   
6. Martin ES, Griffith JG. Myoclonic encephalopathy and neuroblastoma. Report of a case with apparent recovery. Am J Dis Child 1971;122:257-8.
   
   
7. Moe P, Nellhaus G. Infantile polymyoclonia-opsoclonus syndrome and neural crest tumors. Neurology 20:756-764, 1970.
   
   
8. Pranzatelli MR. On the molecular mechanism of adrenocorticotrophic hormone: neurotransmitters and receptors. Exp Neurol 125: 142-161, 1994.
   
   
9. Pranzatelli MR. The immunopharmacology of the opsoclonus-myoclonus syndrome. Clinical Neuropharmacology 19(1):1-47, 1996.
   
   
10. Pranzatelli MR. Opsoclonus-myoclonus-ataxia. In Fernandez-Alvarez E, Arzimanoglou A, Tolosa E (eds) Pediatric Movement Disorders, John Libbey Eurotext: Montrouge, France, pp 120-136, 2005.
    
    
11. Pranzatelli MR, Huang Y, Tate E, et al. Effect of high dose corticotropin on cerebrospinal fluid monoaminergic neurotransmitters or metabolites in corticotropin-responsive pediatric opsoclonus-myoclonus. Movement Disorders 13:522-528, 1998.
    
    
12. Robin A, Vallat M, Tapie P, Vallat J-N. Opsoclonus et troubles neurologiques associés [Opsoclonus and associated neurological disorders]. Arch Ophthalmol (Paris) 1976;36:645-56.
    
    
13. Bolthauser E, Deonna T, Hirt HR. Myoclonic encephalopathy of infants or "dancing eyes syndrome." Hevatica Pediatrica Acta 34:119-133, 1979.
    
    
14. Tate ED, Allison TJ, Pranzatelli MR, Verhulst SJ. (2005)  Neuroepidemiologic trends in 105 cases of pediatric opsoclonus-myoclonus syndrome. J Pediatr Oncol Nurs 22(1): 8-19, 2005.