Ocular microtremor (OMT): a new neurophysiological approach to multiple sclerosis

• Published in: Journal of neurology, neurosurgery and psychiatry Vol. 68; no. 5; pp. 639 - 642
• Main Authors: Bolger, Ciaran, Bojanic, Stana, Sheahan, Noirin, Malone, James, Hutchinson, Michael, Coakley, Davis
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd 01-05-2000; BMJ; BMJ Publishing Group LTD; BMJ Group
• Subjects: Adult; Age; Biological and medical sciences; brain stem; Brain Stem - pathology; Cerebellar Diseases - diagnosis; Female; Humans; Magnetic tape; Male; Medical sciences; Methods; Middle Aged; Multiple sclerosis; Multiple Sclerosis - diagnosis; Multiple Sclerosis - physiopathology; Multiple sclerosis and variants. Guillain barré syndrome and other inflammatory polyneuropathies. Leukoencephalitis; Neurology; neurophysiology; Neurophysiology - methods; ocular microtremor; Ocular Motility Disorders - classification; Ocular Motility Disorders - diagnosis; Ocular Motility Disorders - physiopathology; Patients; physiological tremor; Physiology; piezoelectric; Sensitivity and Specificity; Short Report; Studies; Tremor - classification; Tremor - diagnosis; Tremor - etiology; Human; Nervous system diseases; Multiple sclerosis; Piezoelectric sensor; Tremor; Oscillation frequency; Exploration; Inflammatory disease; Involuntary movement; Eye; Electrodiagnosis; Eye disease; Central nervous system disease; Technique; Neurological disorder
• ISSN: 0022-3050; 1468-330X
• DOI: 10.1136/jnnp.68.5.639

Using a piezoelectric transducer, the frequency and pattern of ocular microtremor (OMT) between 50 normal subjects and 50 patients with multiple sclerosis were compared. Controls were age matched. All records were analysed blindly. The frequency of OMT in the normal group was 86 (SD 6) Hz, which was significantly different from that of the multiple sclerosis group (71 (SD) 10 Hz, p<0.001). Those in the multiple sclerosis group with clinical evidence of brain stem or cerebellar disease (n=36) had an average OMT frequency of 67 (SD 9) Hz (p<0.001) compared with normal (n=86), whereas those with no evidence of brain stem or cerebellar involvement (n=14) had a frequency of 81.2 (SD 6) Hz (p<0.05, n=64). The differences between the two multiple sclerosis groups were also significant (p<0.001, n=50). At least one abnormality (frequency and pattern) of OMT activity was seen in 78% of patients with multiple sclerosis. In the presence of brain stem or cerebellar disease 89% had abnormal records whereas in the absence of such disease 50% had abnormal records. This is the first report of the application of this technique to patients with multiple sclerosis. The results suggest that OMT activity may be of value in the assessment of multiple sclerosis.