Walsh & Hoyt: Paraneoplastic Syndrome of Opsoclonus, Myoclonus, and Ataxia

The syndrome of opsoclonus (and ocular flutter), myoclonus, and ataxia is emphasized here because it can be a remote effect of cancer in patients with neuroblastoma or other malignant tumors. Patients with this paraneoplastic disorder typically experience abrupt onset of the cardinal features, often accompanied by vertigo, nausea, vomiting, and, commonly in children, other symptoms that might otherwise suggest the presence of a viral syndrome. Along with the disorder of eye movement, there is almost always truncal and limb ataxia. In addition, most patients show random coarse or fine myoclonic movements of the head, trunk, or limbs. These myoclonic jerks are not generally accompanied by any epileptiform discharges on the EEG, and they are not synchronous with the abnormal eye movements. Even in patients with advanced cancer, the ataxia and myoclonus may be the major cause of disability. Altered mental status, consisting of apathy, lethargy, and confusion in adults, and irritability and confusion in children, frequently occurs along with the other neurologic manifestations.