Opsoclonus myoclonus

Opsoclonus Myoclonus Syndrome
Classification and external resources
Specialty	neurology
ICD-10	H55
ICD-9-CM	379.59
DiseasesDB	31932
Orphanet	1183
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Opsoclonus Myoclonus Syndrome (OMS), also known as Opsoclonus-Myoclonus-Ataxia (OMA), is a rare neurological disorder of unknown causes which appears to be the result of an autoimmune process involving the nervous system. It is an extremely rare condition, affecting as few as 1 in 10,000,000 people per year. It affects 2 to 3% of children with neuroblastoma and has been reported to occur with celiac disease and diseases of neurologic and autonomic dysfunction.

Symptoms include:

About half of all OMS cases occur in association with neuroblastoma (a cancer of the sympathetic nervous system usually occurring in infants and children).

In most cases OMS starts with an acute flare-up of physical symptoms within days or weeks, but some less obvious symptoms such as irritability and malaise may begin weeks or months earlier.

In children, most cases are associated with neuroblastoma and most of the others are suspected to be associated with a low-grade neuroblastoma that spontaneously regressed before detection. In adults, most cases are associated with breast carcinoma or small-cell lung carcinoma. It is one of the few paraneoplastic (meaning 'indirectly caused by cancer') syndromes that occurs in both children and adults, although the mechanism of immune dysfunction underlying the adult syndrome is probably quite different.

It is hypothesized that a viral infection (perhaps St. Louis encephalitis, Epstein-Barr, Coxsackie B, enterovirus, or just a flu) causes the remaining cases, though a direct connection has not been proven, or in some cases Lyme disease.

OMS is not generally considered an infectious disease. OMS is not passed on genetically.

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Wikipedia