Opsoclonus myoclonus syndrome
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: José Eduardo Riceto Loyola Junior, M.D.[2]
Synonyms and keywords:
Overview
Opsoclonus myoclonus syndrome (OMS) 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.
Historical Perspective
OMS was first described by Dr. M. Kinsbourne in 1962 (The term 'Opsoclonus' was coined by Orezechowski in 1913, but it was classically described and associated with neuroblastoma by Kinsbourne). Other names for OMS include:
- Opsoclonus-Myoclonus-Ataxia (OMA)
- Paraneoplastic Opsoclonus-Myoclonus Ataxia (POMA)
- Kinsbourne syndrome
- Myoclonic Encephalopathy of Infants
- Dancing Eyes-Dancing Feet syndrome
- Dancing Eyes syndrome
Signs and symptoms
Symptoms include:
- opsoclonus (rapid, involuntary, multivectorial (horizontal and vertical), unpredictable, conjugate fast eye movements without intersaccadic [quick rotation of the eyes] intervals)
- myoclonus (brief, involuntary twitching of a muscle or a group of muscles)
- cerebellar ataxia, both truncal and appendicular
- dysphasia (a language disorder in which there is an impairment of speech and of comprehension of speech, caused by brain damage)
- mutism (a social anxiety disorder, in which a person who is normally capable of speech is unable to speak in given situations)
- lethargy
- irritability or malaise
- drooling
- strabismus (a condition in which the eyes are not properly aligned with each other)
- vomiting
- sleep disturbances
About half of all OMS cases occur in association with neuroblastoma (a cancer of the sympathetic nervous system usually occurring in infants and children).
Classification
- [Disease name] may be classified according to [classification method] into [number] subtypes/groups:
- [group1]
- [group2]
- [group3]
- Other variants of [disease name] include [disease subtype 1], [disease subtype 2], and [disease subtype 3].
Pathophysiology
- The pathogenesis of [disease name] is characterized by [feature1], [feature2], and [feature3].
- The [gene name] gene/Mutation in [gene name] has been associated with the development of [disease name], involving the [molecular pathway] pathway.
- On gross pathology, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
- On microscopic histopathological analysis, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
Causes
- [Disease name] may be caused by either [cause1], [cause2], or [cause3].
- [Disease name] is caused by a mutation in the [gene1], [gene2], or [gene3] gene[s].
- There are no established causes for [disease name].
About half of all 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. 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, or enterovirus) causes the remaining cases, though a direct connection has not been proven.
Certainly OMS is not an infectious disease. OMS is not passed on genetically.
Differentiating [disease name] from other Diseases
- [Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as:
- [Differential dx1]
- [Differential dx2]
- [Differential dx3]
Epidemiology and Demographics
- The prevalence of [disease name] is approximately [number or range] per 100,000 individuals worldwide.
- In [year], the incidence of [disease name] was estimated to be [number or range] cases per 100,000 individuals in [location].
Age
- Patients of all age groups may develop [disease name].
- [Disease name] is more commonly observed among patients aged [age range] years old.
- [Disease name] is more commonly observed among [elderly patients/young patients/children].
Gender
- [Disease name] affects men and women equally.
- [Gender 1] are more commonly affected with [disease name] than [gender 2].
- The [gender 1] to [Gender 2] ratio is approximately [number > 1] to 1.
Race
- There is no racial predilection for [disease name].
- [Disease name] usually affects individuals of the [race 1] race.
- [Race 2] individuals are less likely to develop [disease name].
Risk Factors
- Common risk factors in the development of [disease name] are [risk factor 1], [risk factor 2], [risk factor 3], and [risk factor 4].
Natural History, Complications and Prognosis
- The majority of patients with [disease name] remain asymptomatic for [duration/years].
- Early clinical features include [manifestation 1], [manifestation 2], and [manifestation 3].
- If left untreated, [#%] of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
- Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
- Prognosis is generally [excellent/good/poor], and the [1/5/10year mortality/survival rate] of patients with [disease name] is approximately [#%].
Natural History
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.
Complications
Prognosis
Currently there are no clinically established laboratory investigations available to predict prognosis or therapeutic response.
Tumors in children who develop OMA tend to be more mature, showing favorable histology and absence of n-myc oncogene amplification than similar tumors in children without symptoms of OMA (Cooper et al., 2003). Involvement of local lymph nodes is common, but these children rarely have distant metastases and their prognosis, in terms of direct morbidity and mortality effects from the tumor, is excellent (Gesundheit et al., 2004). The three-year survival rate for children with non-metastatic neuroblastoma and OMA was 100% according to Children’s Cancer Group data (gathered from 675 patients diagnosed between 1980 to 1994); three-year survival in comparable patients with OMA was 77% (Rudnick et al., 2001). Although the symptoms of OMA are typically steroid-responsive and recovery from acute symptoms of OMA can be quite good, children often suffer lifelong neurologic sequelae that impair motor, cognitive, language, and behavioral development (Dale, 2003; Mezey and Harris, 2002).
Most children will experience a relapsing form of OMA, though a minority will have a monophasic course and may be more likely to recover without residual deficits (Mitchell et al., 2005). Viral infection may play a role in the reactivation of disease in some patients who had previously experienced remission, possibly by expanding the memory B cell population (Armstrong et al., 2005). Studies have generally asserted that 70-80% of children with OMA will have long-term neurologic, cognitive, behavioral, developmental, and academic impairment. Since neurologic and developmental difficulties have not been reported as a consequence of neuroblastoma or its treatment, it is thought that these are exclusively due to the immune mechanism underlying OMA (Hayward et al., 2001).
One study (Medical and Pediatric Oncology 36:612-622,2001, see below) came to the conclusion that: Patients with OMA and neuroblastoma have excellent survival but a high risk of neurologic sequelae. Favourable disease stage correlates with a higher risk for development of neurologic sequelae. The role of anti-neuronal antibodies in late sequelae of OMS needs further clarification.
Another study (Neuroepidemiologic Trends in 105 US Cases of Pediatric Opsoclonus-Myoclonus Elizabeth D. Tate, Michael R. Pranzatelli, Tyler Allison, Steven Verhurst, Springfield, IL states that: Residual behavioral, language, and cognitive problems occurred in the majority.
Diagnosis
Because OMS is so rare and occurs at an average age of 19 months (6 to 36 months), a diagnosis can be slow. Some cases have been misdiagnosed as having been caused by a virus. After a diagnosis of OMS is made, an associated neuroblastoma is discovered in half of cases, with median delay of 3 months.
Symptoms
- [Disease name] is usually asymptomatic.
- Symptoms of [disease name] may include the following:
- [symptom 1]
- [symptom 2]
- [symptom 3]
- [symptom 4]
- [symptom 5]
- [symptom 6]
Physical Examination
- Patients with [disease name] usually appear [general appearance].
- Physical examination may be remarkable for:
- [finding 1]
- [finding 2]
- [finding 3]
- [finding 4]
- [finding 5]
- [finding 6]
Laboratory Findings
- There are no specific laboratory findings associated with [disease name].
- A [positive/negative] [test name] is diagnostic of [disease name].
- An [elevated/reduced] concentration of [serum/blood/urinary/CSF/other] [lab test] is diagnostic of [disease name].
- Other laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
Imaging Findings
- There are no [imaging study] findings associated with [disease name].
- [Imaging study 1] is the imaging modality of choice for [disease name].
- On [imaging study 1], [disease name] is characterized by [finding 1], [finding 2], and [finding 3].
- [Imaging study 2] may demonstrate [finding 1], [finding 2], and [finding 3].
Other Diagnostic Studies
- [Disease name] may also be diagnosed using [diagnostic study name].
- Findings on [diagnostic study name] include [finding 1], [finding 2], and [finding 3].
Treatment
There is no known definitive cure for OMS. However, several drugs have proven to be effective in its treatment.
Some of medication used to treat the symptoms are:
- ACTH has shown improvements in symptoms but can result in an incomplete recovery with residual deficits.
- Corticosteroids (such as prednisone or methylprednisolone) used at high dosages (500 mg - 2 g per day intravenously for a course of 3 to 5 days) can accelerate regression of symptoms. Subsequent very gradual tapering with pills generally follows. Most patients require high doses for months to years before tapering.
- Intravenous Immunoglobulins (IVIg) are often used with varying results.
- Several other immunosuppressive drugs, such as cyclophosphamide and azathioprine, may be helpful in some cases.
- Chemotherapy for neuroblastoma may be effective, although data is contradictory and unconvincing at this point in time.
- Rituximab has been used with encouraging results. See Immunologic and Clinical Responses to Rituximab in a Child With Opsoclonus-Myoclonus Syndrome Michael R. Pranzatelli, MD, Elizabeth D. Tate, FNP-C, MN, Anna L. Travelstead, BS, MT(ASCP)§ and Darryl Longee,MD
- Other medications are used to treat symptoms without influencing the nature of the disease (symptomatic treatment):
- Trazodone can be useful against irritability and sleep problems
- Additional treatment options include plasmapheresis ("washing the blood", showing similarities to dialysis) for severe, steroid-unresponsive relapses.
A more detailed summary of current treatment options can be found at http://www.omsusa.org/pranzatelli-medications.htm.
The following medications should probably be avoided:
- Midazolam - Can cause irritability.
- Melatonin - Is known to stimulate the immune system.
- Also, see An Innovative Approach to the Problem of Sedating Children with Opsoclonus-Myoclonus Syndrome (Annals of Neurology. 1994;36(3):543-544) for more details
Medical Therapy
- There is no treatment for [disease name]; the mainstay of therapy is supportive care.
- The mainstay of therapy for [disease name] is [medical therapy 1] and [medical therapy 2].
- [Medical therapy 1] acts by [mechanism of action 1].
- Response to [medical therapy 1] can be monitored with [test/physical finding/imaging] every [frequency/duration].
Surgery
- Surgery is the mainstay of therapy for [disease name].
- [Surgical procedure] in conjunction with [chemotherapy/radiation] is the most common approach to the treatment of [disease name].
- [Surgical procedure] can only be performed for patients with [disease stage] [disease name].
Prevention
- There are no primary preventive measures available for [disease name].
- Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
- Once diagnosed and successfully treated, patients with [disease name] are followed-up every [duration]. Follow-up testing includes [test 1], [test 2], and [test 3].
References
- Armstrong MB. Robertson PL. Castle VP. Delayed, recurrent opsoclonus-myoclonus syndrome responding to plasmapheresis. Pediatric Neurology. 33(5): 365-7, 2005 Nov.
- Cooper R. Khakoo Y. Matthay KK. Lukens JN. Seeger RC. Stram DO. Gerbing RB. Nakagawa A. Shimada H. Opsoclonus-myoclonus-ataxia syndrome in neuroblastoma: histopathologic features-a report from the Children's Cancer Group. Medical & Pediatric Oncology. 36(6): 623-9, 2001 Jun.
- Dale RC. Childhood opsoclonus myoclonus. Lancet Neurology. 2(5): 270, 2003 May.
- Gesundheit B. Smith CR. Gerstle JT. Weitzman SS. Chan HS. Ataxia and secretory diarrhea: two unusual paraneoplastic syndromes occurring concurrently in the same patient with ganglioneuroblastoma. Journal of Pediatric Hematology/Oncology. 26(9): 549-52, 2004 Sep.
- Hayward K. Jeremy RJ. Jenkins S. Barkovich AJ. Gultekin SH. Kramer J. Crittenden M. Matthay KK. Long-term neurobehavioral outcomes in children with neuroblastoma and opsoclonus-myoclonus-ataxia syndrome: relationship to MRI findings and anti-neuronal antibodies. Journal of Pediatrics. 139(4): 552-9, 2001 Oct.
- Kinsbourne M. Myoclonic enecphalopathy of infants. Journal of Neurology, Neurosurgery, Psychiatry 25:271-276, 1962.
- Mezey LE. Harris CM. Adaptive control of saccades in children with dancing eye syndrome. Annals of the New York Academy of Sciences. 956: 449-52, 2002 Apr.
- Mitchell WG. Davalos-Gonzalez Y. Brumm VL. Aller SK. Burger E. Turkel SB. Borchert MS. Hollar S. Padilla S. Opsoclonus-ataxia caused by childhood neuroblastoma: developmental and neurologic sequelae. Pediatrics. 109(1): 86-98, 2002 Jan.
- Pranzatelli, M. R., Travelstead, A. L., Tate, E. D., Allison, T. J.,Moticka, E. J., Franz, D. N., Nigro, M. A., Parke, J. T., Stumpf, D. A., Verhulst, S. J. (2004). B- and T-cell markers in opsoclonus-myoclonus syndrome: Immunophenotyping of CSF lymphocytes. Neurology 62: 1526-1532
- Rudnick E. Khakoo Y. Antunes NL. Seeger RC. Brodeur GM. Shimada H. Gerbing RB. Stram DO. Matthay KK. Opsoclonus-myoclonus-ataxia syndrome in neuroblastoma: clinical outcome and antineuronal antibodies-a report from the Children's Cancer Group Study. Medical & Pediatric Oncology. 36(6): 612-22, 2001 Jun.
- Longitudinal Neurodevelopmental Evaluation of Children With Opsoclonus-Ataxia. PEDIATRICS Vol. 116 No. 4 October 2005, pp. 901-907 (doi:10.1542/peds.2004-2377)
External links
- An active OMS Support forum
- short description of OMS
- OMS Support Network
- The National Pediatric Myoclonus Center (US)
- Dancing eyes syndrome (UK name for OMS)
- National Organization for Rare Disorders, Inc.
- A blog about Amelia, an OMS patient diagnosed at 4.5 years (stage I neuroblastoma)
- The experience of a man who had OMS at age 32
- Chase Away OMS Foundation: A non-profit foundation dedicated to funding research to improve the diagnosis, treatment and ultimately find a cure for OMS