Abstract Details

Title Dorsolateral Pontine Lesions Produce Distinct Ocular Motor Abnormalities with Anatomical Correlation

Topic Neuro-ophthalmology/Neuro-otology

Presentation(s) P2 - Poster Session 2 (8:00 AM-9:00 AM)

Poster/Presentation
Number 11-001

Objective This study aimed to investigate the ocular motor abnormalities with their anatomical correlation in dorsolateral pontine (DLP) lesions.

Background Dorsolateral portion of the caudal pons contains the vestibular nucleus and inferior cerebellar peduncle (ICP) that play important roles in conveying and processing vestibular and ocular motor signals. The aim of this study was to investigate abnormal ocular motor findings in DLP lesions to help differentiate them from AVS resulting from benign peripheral vestibulopathy, and determine their anatomical correlation.

Design/Methods Of the 506 patients with pontine infarction in the stroke registry, 18 patients with unilateral DLP lesions (17 with cerebral infarction and one with cavernous malformation) were subjected to analyses of clinical features, and results of neuro-otological evaluations and neuroimaging.

Results Most patients (n=16) presented with an isolated acute vestibular syndrome (AVS). The involved structures within the DLP were ICP in four and vestibular nucleus in the remaining 14. The unilateral ICP lesion showed consistent abnormalities in vestibular and ocular motor tests including ipsilesional nystagmus without gaze-evoked nystagmus (GEN), normal head impulse tests (HITs) and caloric response. Whereas, lesions of the vestibular nucleus showed a broader range of eye movement abnormalities including ipsi-or contralesional nystagmus with GEN, positive HITs, normal or abnormal caloric responses, or fixation nystagmus. Initial MRIs with diffusion-weighted images (< 48 hours) were falsely negative in 41% (n=7) of DLP infarction.

Conclusions This study demonstrates that unilateral DLP lesions frequently present isolated AVS with diverse ocular motor abnormalities. These characteristics may be due to complex involvements of afferent or efferent fibers to and from vestibular nucleus.

Authors/Disclosures
Jae-Hwan Choi (Pusan National University Yangsan Hospital) PRESENTER	Jae-Hwan Choi has nothing to disclose.
Kwang-Dong Choi	Prof. Choi has nothing to disclose.
Sang Min Sung, MD, PhD	Prof. Sung has nothing to disclose.
Hyun Sung Kim, MD (Pusan National University Yangsan Hospital)	Prof. Kim has nothing to disclose.
Bong-Goo Yoo, MD, PhD	Dr. Yoo has nothing to disclose.

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