title: On the origin of oscillopsia during pedunculopontine stimulation.
abstract: We report a case of induced oscillopsia caused by deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN). Recent reports have described involuntary oscillopsia during DBS of the PPN that patients have described as trembling vision. Here we substantiate this observation using infra-red eye tracking. It has been suggested that this phenomenon might be used as an indicator of accurate targeting of the PPN with DBS. Our observations suggest that this phenomenon may not be related to a constricted anatomical structure and therefore such practise may be unwise. Scrutiny has led us to believe that the oscillopsia in our patient is not caused by direct stimulation of the oculomotor nerve as suggested in a previous report, but by stimulation of fibres in the uncinate fasciculus of the cerebellum and the superior cerebellar peduncle, which in turn stimulate the saccadic pre-motor neurones in the brainstem.
authors.affiliation: Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK. ned.jenkinson@dpag.ox.ac.uk
authors.forename: Ned
authors.initials: N
authors.lastname: Jenkinson
authors.forename: John-Stuart
authors.initials: JS
authors.lastname: Brittain
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Hicks
authors.forename: Christopher
authors.initials: C
authors.lastname: Kennard
authors.forename: Tipu Z
authors.initials: TZ
authors.lastname: Aziz
mesh_terms: D046690:Deep Brain Stimulation / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000209:etiology* / Q000503:physiopathology; D010300:Parkinson Disease / Q000503:physiopathology / Q000628:therapy*; D045042:Pedunculopontine Tegmental Nucleus / Q000503:physiopathology*