Oculomotor Abnormalities and Nystagmus in Brainstem Disease: A Mini Review

The brainstem represents a structure of prominent importance for the genera-tion and control of eye movements (saccades, smooth pursuit, the vestibulo-ocular re-flex, VOR, vergence and gaze holding). Besides its several physiological functions of vi-tal importance, the brainstem plays a role in the coordination of balance and move-ments. Therefore, eye movement disorders of brainstem origin are frequently associat-ed with vertigo, imbalance, unsteady gait and walk and diplopia upon changing head and body posture. Nonetheless, an adequate knowledge of the neural structures in-volved in oculomotor and vestibular control allows for the identification and accurate localization of a wide variety of brainstem syndrome. However, oculomotor abnormali-ties arising from brainstem disease constitute an extremely complex challenge for the otoneurologist by virtue of the remarkable diversity of causes (vascular, traumatic, de-generative, neoplastic) of their variable severity, of their clinical course (acute, fluctu-ating or progressive) and finally by virtue of concomitant involvement of other central structures (mainly cerebellum). F Nonetheless, an adequate knowledge of the neural structures involved in oculomotor and vestibular control allows for the identification and accurate localization of a wide variety of brainstem syndrome. or these reasons, eye movement disorders and nystagmus of brainstem origin are frequently associated not only with vertigo and imbalance but with a wide range of other neurological signs. This short review describes the pathophysiology and the clinical characteristics of oculomo-tor disorders and nystagmus in brainstem disorders.