Alexander's law: Its behavior and origin in the human vestibulo‐ocular reflex
- 1 December 1984
- journal article
- research article
- Published by Wiley in Annals of Neurology
- Vol. 16 (6), 714-722
- https://doi.org/10.1002/ana.410160614
Abstract
Alexander's law refers to the phenomenon in which the spontaneous nystagmus of a patient with a vestibular lesion is more intense when the patient looks in the quick‐phase than in the slow‐phase direction. Alexander's law was investigated in normal subjects as well as patients with vestibular lesions. During sinusoidal rotations of normal subjects, there was no trace of this phenomenon when subjects looked 25 degrees left and right in the dark. The phenomenon of Alexander's law is therefore created centrally and is not due to any mechanical properties of the orbit. During rotation at constant velocity in the dark, normal subjects did weakly demonstrate Alexander's law because of a mild gaze‐evoked nystagmus present in normal subjects in the dark. Gaze‐evoked nystagmus from a cerebellar lesion involved a pronounced demonstration of Alexander's law during rotatory nystagmus. In patients with a vestibular lesion and a mild spontaneous nystagmus in the dark that obeyed Alexander's law, the nystagmus reversed upon far gaze in the slow‐phase direction. We propose that in patients with a vestibular lesion, the phenomenon of Alexander's law is created by the sum of vestibular nystagmus and an abnormally large gaze‐evoked nystagmus that is consequent to the vestibular lesion. This conclusion has a number of neurological implications concerning the ways in which the nervous system attempts to compensate for vestibular lesions.Keywords
This publication has 15 references indexed in Scilit:
- Short- and long-term modifications of vestibulo-ocular response dynamics following unilateral vestibular nerve lesions in the catExperimental Brain Research, 1983
- Velocity storage in the vestibulo-ocular reflex arc (VOR)Experimental Brain Research, 1979
- Impulsive and sinusoidal rotatory testing: A comparison with results of caloric testingThe Laryngoscope, 1979
- A model of Alexander's law of vestibular nystagmusBiological Cybernetics, 1979
- Neuronal activity in the vestibular nuclei of the alert monkey during vestibular and optokinetic stimulationExperimental Brain Research, 1977
- Voluntary, Non-Visual Control of The Human Vestibulo-Ocular ReflexActa Oto-Laryngologica, 1976
- Precise recording of human eye movementsVision Research, 1975
- The effect of cerebellectomy on the cat's vestibulo-ocular integratorBrain Research, 1974
- Accuracy of saccadic eye movements and maintenance of eccentric eye positions in the darkVision Research, 1973
- Eye Movement Control in PrimatesScience, 1968