Why do patients with PSP fall? Evidence for abnormal otolith responses

Neurology. 2008 Mar 4;70(10):802-9. doi: 10.1212/01.wnl.0000304134.33380.1e. Epub 2008 Jan 16.


Background: Patients with progressive supranuclear palsy (PSP) fall frequently, beginning early in the course of their disease. Abnormal vestibulospinal reflexes are suspected, but the angular vestibulo-ocular reflex, which is mediated by the labyrinthine semicircular canals, survives late into the course of the disease.

Objective: To test the hypothesis that otolithic-mediated reflexes are abnormal in PSP.

Methods: We tested otolith-ocular reflexes (the translational vestibulo-ocular reflex [tVOR]) during combined rotation-translation in nine patients with PSP and nine age-matched control subjects; subjects viewed far and near targets. We also tested click-induced otolith-spinal reflexes (vestibular-evoked myogenic potentials [VEMPs]) in 10 patients with PSP and 30 age-matched controls.

Results: All patients with PSP had small tVOR responses during near viewing that were, on average, only 12% of those of control subjects (p = 0.001). Patients with PSP also showed a reduction of the amplitude of VEMPs compared to control subjects (median [range]: 54.3 [16.8 to 214] vs 149 [11.6 to 466], p = 0.001).

Conclusions: Taken together, these results indicate that abnormal otolith-mediated reflexes may be at least partly responsible for frequent falls in progressive supranuclear palsy, and deserve further study.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Accidental Falls
  • Aged
  • Efferent Pathways / physiopathology
  • Female
  • Head Movements / physiology
  • Humans
  • Male
  • Middle Aged
  • Oculomotor Muscles / innervation
  • Oculomotor Muscles / physiopathology
  • Otolithic Membrane / physiopathology*
  • Postural Balance / physiology
  • Reflex, Abnormal / physiology
  • Reflex, Vestibulo-Ocular / physiology
  • Saccule and Utricle / physiopathology
  • Semicircular Ducts / physiopathology
  • Supranuclear Palsy, Progressive / complications*
  • Supranuclear Palsy, Progressive / physiopathology*
  • Vestibular Diseases / diagnosis
  • Vestibular Diseases / etiology*
  • Vestibular Diseases / physiopathology*
  • Vestibular Function Tests
  • Vestibular Nuclei / physiopathology
  • Vestibule, Labyrinth / physiopathology*