Persistent figure-eight and side-to-side head shaking is a marker for rhombencephalosynapsis.

Background: Head-shaking stereotypies have been described in patients with neurological impairment. We noted an unusual preponderance of head shaking in patients with rhombencephalosynapsis (RES). We sought to delineate the movements further and determine whether oculomotor and vestibular testing could reveal their cause.
Methods: Information was collected from direct observation, video review and parental questionnaire from 59 patients with RES. Oculomotor and vestibular testing was performed in 4 children.
Results: Of 59 patients, 50 had persistent head shaking that was often observed years before RES was recognized. Three affected children demonstrated abnormal central vestibular processing.
Conclusions: Head-shaking is common in RES. These characteristic movements may provide input to a defective vestibular system or may represent a motor pattern that is usually suppressed by vestibular feedback. Persistent head shaking should alert clinicians to the possible presence of a congenital hindbrain abnormality that affects the vestibulocerebellum, particularly RES.
(© 2013 Movement Disorder Society.)