title: Intracranial recording from the brain-stem and the trigeminal nerve following upper lip stimulation.
abstract: Short latency evoked potentials following stimulation of the upper lip were recorded intracranially during neurosurgical procedures in 14 patients. In 10 patients, a suboccipital craniectomy provided direct access to the trigeminal root and the pons at the root entry zone. Direct recordings from the trigeminal root were characterized by a large triphasic potential at 2.4-2.7 msec. The latency of this potential increased as a result of moving the recording electrode proximally towards the brain-stem. The same potential could be recorded from the brain-stem surface at a latency suggesting an intra-axial presynaptic origin. A second component, N4.7, was recorded from over the most rostral aspect of the brain-stem in 3 patients and from the tentorium free edge in 4 patients. This potential of smaller amplitude did not show significant difference in latency or polarity at various electrode locations, suggesting a deep diencephalic origin remote from the recording electrode.
authors.affiliation: Department of Neurosurgery, Rambam (Maimonides) Medical Center, Haifa, Israel.
authors.forename: J F
authors.initials: JF
authors.lastname: Soustiel
authors.forename: A V
authors.initials: AV
authors.lastname: Chistyakov
authors.forename: H
authors.initials: H
authors.lastname: Hafner
authors.forename: E
authors.initials: E
authors.lastname: Youssim
authors.forename: M
authors.initials: M
authors.lastname: Feinsod
mesh_terms: D001921:Brain / Q000601:surgery; D001933:Brain Stem / Q000503:physiopathology*; D002530:Cerebellopontine Angle; D002531:Cerebellum / Q000503:physiopathology; D004558:Electric Stimulation; D005071:Evoked Potentials; D006801:Humans; D007432:Intraoperative Period; D008046:Lip / Q000503:physiopathology*; D011930:Reaction Time; D014276:Trigeminal Nerve / Q000503:physiopathology*