Parkinsonism and Related Disorders
journal homepage: www.elsevier.com/locate/parkreldis

Letter to the Editor

1. Introduction

Opsoclonus-Myoclonus Syndrome (OMS) is a rare neurologic
condition comprised of the two hallmark signs of dysmetric ocular
ataxia and myoclonic jerks of the extremities. The eye movements
have been described as ‘‘dancing eyes’’. The eyes dart involuntarily
away from the point of visual fixation or pursuit in a manner that
can be considered a myoclonic jerk of the extra-ocular muscles.
When the patient attempts to align the gaze on a point, there may
be dysmetric overshoot of the eyemovement.Myoclonicmovements
of the extremities occur at rest, and intended actions are ataxic. The
mean age of presentation of OMS in childhood is 14 months, and it
presents as a paraneoplastic syndromeassociated with an underlying
tumor in 50–60% of the cases [1,2], most commonly neuroblastoma
or ganglioneuroblastoma. Recent research has revealed the presence
of several auto-antibodies including anti-Hu, anti-Ri, a-Enolase,
KSRP and NLK [3] in patients with OMS. These antibodies bind to
an array of targets in the cerebellum andmaymanifest as oligoclonal
bands in cerebrospinal fluid. The syndrome is often associated
with behavioral changes such as aggression, irritability, and
insomnia. Post-vaccine OMS is not well described in the pediatric
population.