opsoclonus - myoclonus - ataxia syndrome ( omas ) , also called  kinsbourne syndrome  or 
dancing eye syndrome ,  is a serious , rare , and often chronic neurological disorder .
omas consists of three main symptoms : opsoclonus ( conjugate , multidirectional , chaotic eye movements ) , myoclonus ( nonepileptic limb jerking that can also involve the head and face ) and truncal ataxia , which cause gait imbalance .
omas is generally a paraneoplastic or parainfectious entity , but in children , it is most commonly associated with occult neuroblastoma ( nb ) in about 50% of cases and between 2% and 3% of children with nb have omas .
although most patients with nb and omas have good survival rates , 70%80% of these children will have long - term neurologic sequelae . in pediatric age , omas may be associated with neuroblastic tumors ( nb , ganglioneuroblastoma , or ganglioneuroma ) .
the diagnosis of omas may be difficult in some patients and should be considered even when only some of the features are present .
international consensus has described three of the following four diagnostic criteria should be present to describe the typical syndrome : ( 1 ) opsoclonus , ( 2 ) myoclonus / ataxia , ( 3 ) behavioral change and/or sleep disturbance , and ( 4 ) nb . we present a retrospective study of five children presented to the pediatric oncology clinic ( poc ) of all india institute of medical sciences ( aiims ) with a diagnosis of opsoclonus - myoclonus syndrome ( oms ) .
the objective of this study was to describe the clinical profile and outcome of this disorder .
the medical records of all children presented to poc , department of pediatrics , aiims , with a diagnosis of opsoclonus - myoclonus were retrieved and reviewed .
the diagnosis of opsoclonus - myoclonus was based on a constellation of any three of the four clinical features : opsoclonus , myoclonus , ataxia , and encephalopathy / irritability / behavioral change / sleep disturbance .
outcome was assessed on follow - up by direct assessment and by telephonic communication ( in one patient ) .
a total of six patients with a diagnosis of opsoclonus - myoclonus were admitted over 4-year period [ table 1 ] .
opsoclonus , myoclonus , ataxia , and encephalopathy / behavioral abnormalities ( irritability / sleep disturbance ) were present in all children at presentation .
the duration of symptoms at the time of presentation was in the range of 610 months .
clinical profile and outcome in six children with opsoclonus - myoclonus syndrome the reasons for the delay in diagnosis included misdiagnosis by peripheral physicians and delayed referral to our center .
all children had paraneoplastic opsoclonus - myoclonus ( two left paravertebral ganglioneuroblastoma , two left paravertebral nb , one left paravertebral plus left psoas muscle ganglioneuroblastoma , and one right paravertebral ganglioneuroblastoma ) [ figures 13 ] .
the diagnosis of tumor was made on contrast - enhanced computed tomography scan ( ct ) and magnetic resonance imaging ( mri ) of the chest , abdomen , and pelvis ( 3 ct scan and 3 mri ) .
tests for urinary excretion of vanillylmandelic acid ( vma ) were negative in all cases .
iodine-131 metaiodobenzylguanidine scintigraphy scan ( i-131 mibg ) was performed in all cases , but it detected mibg concentrating tumor only in two cases .
( case 2 ) ( original ) axial section showing well - defined enhancing soft - tissue mass lesion ( 3.5 cm  2 cm  1.4 cm ) seen in the left upper psoas muscle extending into left neural foramen in between l2 and l3 vertebra up to dura mater ( a and b ) ( case 3 ) axial section and coronal section showing right paravertebral mass of size 1.5 cm  0.6 cm  2.4 cm at the level of d6 to d8 vertebral body ( a and b ) ( case 5 ) axial and coronal section showing well - defined left paravertebral mass lesion 2 cm  1.8 cm  2.9 cm at the level of d6 to d8 vertebral body an initial diagnosis of omas was made in all children .
three children received injection adrenocorticotropic hormone ( acth ) ; two children received injection acth plus injection methylprednisolone followed by oral steroids over 4 weeks .
one child ( case 1 ) also received intravenous immunoglobulin ( ivig ) and oral clonazepam and risperidone in view of abnormal behavior ( excessive irritability , biting , and head banging ) .
one child ( case 5 ) had spontaneous improvement and complete recovery without specific immunomodulator therapy .
of the six cases with paraneoplastic oms , four cases were treated with surgical resection of tumor and chemotherapy . in one child (
case 5 ) , treatment was deferred by parents but on telephonic communication that the child was symptoms free and healthy at 9 months after presentation to us . in another case (
case 6 ) , she received only injection acth , surgery , and chemotherapy were denied by parents .
after follow - up of 24 months , the child was asymptomatic , but ct of the abdomen revealed mass of same size that was documented 2 years back .
one child ( case 3 ) died of febrile encephalopathy ( not related to disease ) .
other names for oms include omas , paraneoplastic opsoclonus - myoclonus ataxia , kinsbourne syndrome , myoclonic encephalopathy of infants , dancing eyes - dancing feet syndrome , and dancing eyes syndrome . in our study , all six children were between 2 and 3 years of age , similar to the trend seen in other reports , in which oma was uncommonly diagnosed before 1 year of age . one possible explanation for the low incidence in infancy may be due to ability to develop specific antibodies is less in younger infants .
we observed , alike to previously published studies , a similar median age at clinical presentation , acute / subacute onset of presentation , association of nb , and response to immunomodulator therapy .
we have found poor sensitivity of urine vma in our case series with similar findings reported by brunklaus et al .
we also observed poorer sensitivities for mibg scintigraphy scan in contrast with the reported high sensitivity ( up to 95% ) for detection of nb as compared to an abdominal ct scan / mri . in adults , oms
is seen in relation to malignancies of the breast and lung ( small cell carcinoma ) , in association with antibodies which are directed against an rna binding antigen from the anti - hu antibody .
this antibody is not found in children in oms of nb . in children , nb which presents with oms is more mature
, shows a favorable histology , and absence of n - myc oncogene amplification than tumors which occur without symptoms of oms .
oms , the most frequent paraneoplastic syndrome in pediatric age group , remains a challenge for treatment .
various immunomodulatory therapies have been used including steroids , ivig , cyclophosphamide , and more recently , rituximab .
patients with nb and oma have been reported to have excellent survival . according to children 's cancer group data ,
the 3-year survival rate for children with nonmetastatic nb and oma was 100% ( reported from 675 patients who were diagnosed between 1980 and 1994 ) in compared to 77% in non - oma .
described a case series of 11 patients ( largest case series from india ) with a diagnosis of opsoclonus - myoclonus ( of the 11 , 4 had paraneoplastic etiology ) and concluded that children with paraneoplastic opsoclonus had more relapses and had a poor outcome as compared to an idiopathic group .
, in our series , all six children had paraneoplastic oms , and all had good outcome . this tumor is known to have spontaneous regression .
our one child ( case 5 ) had spontaneous symptomatic resolution , and another child ( case 6 ) is doing well without surgery and chemotherapy .
we have seen a good therapeutic response with immunomodulators , including acth , ivig , and corticosteroids .
because of the small number of patients , it is difficult to compare these therapies .
no one had relapse in our series contradicting to those reported by tate et al .
( up to 52% ) could be due to the small number of patients in our study . in most children with nb ,
the characteristic feature is the response of this syndrome to corticosteroids and acth and the resolution of the neurological signs when the nb is treated .
children often develop lifelong neurologic sequelae that impair motor , cognitive , language , and behavioral developments .
observed that in older children , late effects are less likely seen because basic motor and cognition have already been formed .
rudnick et al . reported that children with more advanced stage disease had better outcomes with regard to neurologic sequelae . one possible explanation for this association may be that patients with advanced stage disease require more intensive therapy that usually includes chemotherapy .
russo et al . suggested that chemotherapy may improve neurologic outcome in children with oma and nb , possibly due to its immunosuppressive effects . in our study , five children with oms responded with acth and steroids ; one child recovered spontaneously .
the outcome was good in our all children , whereas in the study by tate et al . , the outcome was independent of etiology .
other studies have also observed better outcome of idiopathic opsoclonus - myoclonus . we did not observe progressive developmental and behavioral problems in our patients , which could be due to small number of patients and short follow - up .
oms is a rare disorder , but it affects children more frequently than adults and exhibits an excellent rate of survival . screening for an occult nb is necessary in all children with this syndrome .
oms ( paraneoplastic ) had a good outcome without significant neurological deficits in our experience .
 the opsoclonus - myoclonus ataxia syndrome ( omas ) also called  kinsbourne syndrome  or  
 dancing eye syndrome  is a rare but serious disorder characterized by opsoclonus , myoclonus , and ataxia , along with extreme irritability and behavioural changes . 
 data on its epidemiology , clinical features , and outcome are limited worldwide . 
 the aim of the study was to evaluate the clinical profile and outcome of children with omas . 
 a retrospective data of all children presented to pediatric oncology clinic with a diagnosis of opsoclonus - myoclonus from 2013 to 2016 were collected . 
 6 patients with a diagnosis of omas were presented over a 4-year period . 
 all 6 cases had paraneoplastic etiology . 
 all children had good outcome without any relapse . 
 paraneoplastic opsoclonus myoclonus had a good outcome in our experience . 
Introduction
Methods
Results
Discussion
Conclusion
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