Synchronised Paroxysmal Ocular Tilt Reaction and Limb Dystonia

ABSTRACTA case of paroxysmal ocular tilt reaction due to a midbrain cavernoma showing co-existing limb dystonia is described with particular reference to the synchronisation of eye and limb paroxysms. The single case has been observed over a 20-year period with video documentation of eye and limb movements. The function of the relevant neuro-anatomical circuits have been investigated. The now 51-year-old female patient suffered from a right midbrain haemorrhage 20 years earlier. She developed a synchronized paroxysmal ocular tilt reaction and focal limb dystonia, associated with a unilateral startle-like response. Video-oculography and electromyography during paroxysms demonstrated left forearm electromyography spikes time locked with bursts of ocular torsion. Whilst the ocular tilt reaction may be explained by a single irritative lesion of the right interstitial nucleus of Cajal, additional involvement of the right rostral interstitial nucleus of the medial longitudinal fasciculus was suggested by abnorm...