Torsional deviations with voluntary saccades caused by a unilateral midbrain lesion

• Published in: BMJ case reports Vol. 2009; p. bcr0820080807
• Main Authors: Kremmyda, Olympia, Büttner-Ennever, Jean A, Büttner, Ulrich, Glasauer, Stefan
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd 01.01.2009; BMJ Publishing Group LTD
• Subjects: 51–70 years; Adult; Europe (West); Eye movements; Female; Findings that shed new light on the possible pathogenesis of a disease or an adverse effect; Humans; Lesions; Magnetic Resonance Imaging; Male; Mesencephalon - diagnostic imaging; Mesencephalon - pathology; Mesencephalon - physiopathology; Middle Aged; Ocular Motility Disorders - etiology; Patients; Psychiatry; Saccades - physiology; Torsion Abnormality - etiology; Torsion Abnormality - physiopathology; Velocity; White
• ISSN: 1757-790X; 1757-790X
• DOI: 10.1136/bcr.08.2008.0807

Three dimensional eye rotations were measured using the magnetic search coil technique in a patient with a lesion of the right rostral interstitial nucleus of the medial longitudinal fasciculus (RIMLF) and in four control subjects. Up to 10° contralesional torsional deviations with each voluntary saccade were revealed, which also could be seen during bedside examination. There was no spontaneous nystagmus. Based on MRI criteria, the lesion involved the RIMLF but spared the interstitial nucleus of Cajal. To date, this deficit has not been described in patients. Our results support the hypothesis that the vertical-torsional saccade generator in humans is organised similarly as in monkeys: each RIMLF encodes torsional saccades in one direction, while both participate in vertical saccades.