Direct approach to the ventrolateral medulla for cavernous malformation--case report.

A 49-year-old man presented with symptomatic cavernous malformation in the ventrolateral portion of the medulla oblongata manifesting as left-sided numbness and gait disturbance. Neurological examination disclosed sensory disturbance on the left, cerebellar ataxia, nystagmus, dysphagia, and right hypoglossal nerve paresis. Magnetic resonance imaging revealed a cavernous malformation with hemorrhage occupying the right paramedian field of the medulla oblongata. The patient underwent complete removal of the lesion through vertical incision of the bulging surface of the ventrolateral medulla, anatomically coinciding with the inferior olive. The neurological deficits improved without additional postoperative deficits. This unusual microsurgical approach through a ventrolateral medullary incision permits direct resection of a subpial intrinsic lesion, even on the ventral medulla.