title: Approach to dorsal pontine lesions via the fourth ventricle with SSEP monitoring: a report of two cases.
abstract: Operative morbidity is a limiting factor for the trans-fourth ventricular approach to brain stem lesions. The usefulness of somatosensory evoked potentials (SSEP) in this approach has not been established. Two patients with pontine lesions were operated on with SSEP monitoring using the trans-fourth ventricular approach. One patient had a cavernous haemangioma and the other had a chordoma invading the pons. SSEP remained normal in the first, and a slight transitory decrease of the amplitude was observed in the second patient. The lesions were macroscopically totally removed with minimal postoperative neurological deterioration. In this approach it is assumed that SSEP monitoring was especially helpful for removal of the lesions extending deeply in the pons.
authors.affiliation: Department of Neurosurgery and Department of Neurology, University Hospital of Zürich, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Ogata
authors.forename: H G
authors.initials: HG
authors.lastname: Wieser
authors.forename: Y
authors.initials: Y
authors.lastname: Yonekawa