Abducens nucleus syndrome due to pontine haemorrhage.

Introduction Abnormalities of horizontal gaze are common in strokes involving the caudal part of the pons and generally associated with motor, sensory, cerebellar and cranial nerve dysfunction. Isolated abducens nerve palsy is rare [1, 2] and due to a small lesion which affects the radicular fascicles of the 6th cranial nerve and spares the abducens nucleus [3] . Conversely, abducens nucleus lesions produce a conjugate paralysis [4] but not an isolated lateral rectus muscle palsy. We report a case of unilateral conjugate gaze paralysis due to a small pontine haemorrhage involving the abducens nucleus which turned into a paralysis of the lateral rectus muscle.