The origin of downbeat nystagmus: an asymmetry in the distribution of on-directions of vertical gaze-velocity Purkinje cells.
Various hypotheses on the origin of cerebellar downbeat nystagmus (DBN) have been presented; the exact pathomechanism, however, is still not known. Based on previous anatomical and electrophysiological studies, we propose that an asymmetry in the distribution of on-directions of vertical gaze-velocity Purkinje cells leads to spontaneous upward ocular drift in cerebellar disease, and therefore, to DBN. Our hypothesis is supported by a computational model for vertical eye movements.
Marti
Sarah
S
Neurology Department, Zurich University Hospital, Frauenklinikstrasse 26, CH-8091 Zurich, Switzerland. sarah.marti@usz.ch
Straumann
Dominik
D
Glasauer
Stefan
S
D005403:Fixation, Ocular; D006801:Humans; D008959:Models, Neurological; D009759:Nystagmus, Pathologic / Q000209:etiology / Q000503:physiopathology*; D009801:Oculomotor Muscles / Q000503:physiopathology; D011689:Purkinje Cells / Q000502:physiology*; D012016:Reference Values; D012438:Saccades / Q000502:physiology