The role of volitional effort in the Bielschowsky Head Tilt Test: A clinical and oculographic assessment

M. C. Brodsky, T. Haslwanter, A. A. Kori, D. Straumann

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Purpose: To determine whether volitional effort on the part of the subject can influence the results of the Bielschowsky Head Tilt Test. Patients and Methods: Bielschowsky Head Tilt testing was performed in five normal subjects. Vertical amplitudes were measured with prism alternate cover testing when the head tilt was voluntary (volitionally maintained in a tilted position by the subject), forced (restrained in the tilted position by the examiner while the patient actively resisted) and active (restrained in a tilted position by the examiner with the subject actively trying to increase the tilt). Three-dimensional scleral search coil recordings were performed in three additional normal subjects using the same paradigm to determine the effect of volition on the torsional positions of the eyes. Results: No vertical deviation of the eyes was detectable with prism alternate cover testing in any position of tilt, regardless of whether the tilt was voluntary, forced, or active. Volitional attempts to tilt the head were preceded by a transient ipsiversive torsional movement of the measured eye, which was quickly followed by a normal ocular counterroll. Following completion of the counterroll, the position of the eyes was constant for any position of head tilt, regardless of whether the tilt was forced, active, or voluntary. Conclusion: Anticipatory torsional movements of the eyes are evoked by an attempted volitional head movement in the roll plane and its associated innervation to the cervical musculature. However, these volitional movements do not alter the final torsional position of the eyes, which is a function of the degree of head tilt and the normal ocular counterroll. These anticipatory torsional movements do not influence the results of the Bielschowsky Head Tilt Test clinically by prism alternate cover testing.

Original languageEnglish (US)
Pages (from-to)325-330
Number of pages6
JournalBinocular Vision and Strabismus Quarterly
Volume15
Issue number4
StatePublished - Dec 14 2000

Keywords

  • 'Forced' head tilt difference
  • Bielschowsky Head Tilt Test
  • Binocular vision
  • Cyclovertical eye muscles
  • Eye movements
  • Head posture, abnormal
  • Hypertropia
  • Neurology
  • Normal physiology, ocular
  • Strabismus, tests for
  • Testing
  • Torsional eye movements

ASJC Scopus subject areas

  • Ophthalmology

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