Wernekinck commissure syndrome: An illustrative case with review of various etiologies

Wernekinck commissure syndrome (WCS) is an uncommon brainstem disorder caused by lesions in the caudal midbrain, affecting the decussation of the superior cerebellar peduncles, medial longitudinal fasciculi, and central tegmental tract. We report a 60-year-old hypertensive chronic smoker presenting with sudden-onset gait and limb ataxia, dysarthria, and diplopia. Neurological examination revealed bilateral internuclear ophthalmoplegia and prominent cerebellar signs with preserved sensorimotor function and consciousness. Magnetic resonance imaging demonstrated a paramedian infarct at the level of the Wernekinck commissure, confirming the diagnosis. A literature review of seven published cases highlights that while posterior circulation infarcts are the most frequent cause, other etiologies such as inflammatory and demyelinating disorders have been reported. Awareness of this rare syndrome is critical, as timely neuroimaging and recognition of characteristic clinical features can facilitate prompt treatment and rehabilitation, leading to favorable outcomes in most cases.