Torsional nystagmus: quantitative features and possible pathogenesis.
Noseworthy JH., Ebers GC., Leigh RJ., Dell'Osso LF.
We measured eye rotations in three planes in a patient with acquired, torsional nystagmus. This nystagmus had linear or increasing-velocity waveforms, was increased after active pitch rotations of the head, and was suppressed by convergence. Magnetic resonance imaging demonstrated a midpontine lesion that was probably a venous angioma. We postulate that torsional nystagmus in this patient was due to disruption of central vestibular connections.