Computerized screening of the human vestibulospinal system.

The vestibular nerve projects rostrally via the ascending medial longitudinal fasiculus (MLF) to eventually supply the ocular muscles and also projects caudally via the descending MLF to eventually supply the spinal and limb musculature. Electronystagmographic techniques are designed to evaluate only portions of the vestibulo-ocular and oculomotor systems. Vestibular lesions affecting only the caudal vestibular nerve distributions or lesions affecting both neural distributions, therefore, cannot be objectively assessed except for the vestibulo-ocular component. A promising recording technique for the evaluation of the vestibulospinal system has been developed and tested in the Raymond E. Jordan Human Vestibular Systems Laboratory. A comparison of two data analysis techniques in normal subjects, unilateral vestibular lesion patients and patients with unilateral lesions of the cerebellar hemispheres have provided pilot data which indicate that the vestibulospinal stability test technique holds considerable promise for both research and clinical evaluation of the human vestibulospinal system.