Abstract
OBJECTIVES—Somatosensory evoked potentials (SSEPs) and brainstem auditory evoked potentials (BAEPs) have been increasingly utilised during surgery for intracranial aneurysms to identify cerebral ischaemia. Between July 1994 and April 1996, we surgically treated 70 aneurysms in 49 consecutive patients (58 operations) with the aid of intraoperative evoked potential monitoring. This study sought to evaluate the usefulness of SSEP and BAEP monitoring during intracranial aneurysm surgery. METHODS—Mean patient age was 51.9 (range 18-79) years. The sizes of the aneurysms were 3-4 mm (15), 5-9 mm (26), 10-14 mm (11), 15-19 mm (seven), 20-24 mm (six), and >25 mm (five). SSEPs were monitored in 58 procedures (100%) and BAEPs in 15 (26%). The neurological status of the patients was evaluated before and after surgery. RESULTS—Thirteen of the 58 procedures (22%) monitored with SSEPs had SSEP changes (12 transient, one persistent); 45 (78%) had no SSEP changes. Three of 15 patients (20%) monitored with BAEPs had changes (two transient, one persistent); 12 (80%) had no BAEP changes. Of the 14 patients with transient SSEP or BAEP changes, these changes resolved with adjustment or removal of aneurysm clips (nine), elevating MAP (four), or retractor adjustment (one). Mean time from precipitating event to electrophysiological change was 8.9 minutes (range 3-32), and the mean time for recovery of potentials in patients with transient changes was 20.2 minutes (range 3-60). Clinical outcome was excellent in 39 patients, good in five, and poor in three (two patients died), and was largely related to pretreatment grade. CONCLUSIONS—SSEPs and BAEPs are useful in preventing clinical neurological injury during surgery for intracranial aneurysms and in predicting which patients will have unfavourable outcomes.
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Selected References
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- Aravabhumi S., Izzo K. L., Bakst B. L. Brainstem auditory evoked potentials: intraoperative monitoring technique in surgery of posterior fossa tumors. Arch Phys Med Rehabil. 1987 Mar;68(3):142–146. [PubMed] [Google Scholar]
- Branston N. M., Ladds A., Symon L., Wang A. D. Comparison of the effects of ischaemia on early components of the somatosensory evoked potential in brainstem, thalamus, and cerebral cortex. J Cereb Blood Flow Metab. 1984 Mar;4(1):68–81. doi: 10.1038/jcbfm.1984.9. [DOI] [PubMed] [Google Scholar]
- Branston N. M., Strong A. J., Symon L. Extracellular potassium activity, evoked potential and tissue blood flow. Relationships during progressive ischaemia in baboon cerebral cortex. J Neurol Sci. 1977 Jul;32(3):305–321. doi: 10.1016/0022-510x(77)90014-4. [DOI] [PubMed] [Google Scholar]
- Branston N. M., Symon L., Crockard H. A., Pasztor E. Relationship between the cortical evoked potential and local cortical blood flow following acute middle cerebral artery occlusion in the baboon. Exp Neurol. 1974 Nov;45(2):195–208. doi: 10.1016/0014-4886(74)90112-5. [DOI] [PubMed] [Google Scholar]
- Buchthal A., Belopavlovic M., Mooij J. J. Evoked potential monitoring and temporary clipping in cerebral aneurysm surgery. Acta Neurochir (Wien) 1988;93(1-2):28–36. doi: 10.1007/BF01409899. [DOI] [PubMed] [Google Scholar]
- Buchthal A., Belopavlovic M. Somatosensory evoked potentials in cerebral aneurysm surgery. Eur J Anaesthesiol. 1992 Nov;9(6):493–497. [PubMed] [Google Scholar]
- Djurić S., Milenković Z., Klopcić-Spevak M., Spasić M. Somatosensory evoked potential monitoring during intracranial surgery. Acta Neurochir (Wien) 1992;119(1-4):85–90. doi: 10.1007/BF01541787. [DOI] [PubMed] [Google Scholar]
- Drake C. G. Cerebral arteriovenous malformations: considerations for and experience with surgical treatment in 166 cases. Clin Neurosurg. 1979;26:145–208. doi: 10.1093/neurosurgery/26.cn_suppl_1.145. [DOI] [PubMed] [Google Scholar]
- Drake C. G., Friedman A. H., Peerless S. J. Posterior fossa arteriovenous malformations. J Neurosurg. 1986 Jan;64(1):1–10. doi: 10.3171/jns.1986.64.1.0001. [DOI] [PubMed] [Google Scholar]
- Ducati A., Landi A., Cenzato M., Fava E., Rampini P., Giovanelli M., Villani R. Monitoring of brain function by means of evoked potentials in cerebral aneurysm surgery. Acta Neurochir Suppl (Wien) 1988;42:8–13. doi: 10.1007/978-3-7091-8975-7_2. [DOI] [PubMed] [Google Scholar]
- Emerson R. G., Turner C. A. Monitoring during supratentorial surgery. J Clin Neurophysiol. 1993 Oct;10(4):404–411. doi: 10.1097/00004691-199310000-00002. [DOI] [PubMed] [Google Scholar]
- Friedman W. A., Chadwick G. M., Verhoeven F. J., Mahla M., Day A. L. Monitoring of somatosensory evoked potentials during surgery for middle cerebral artery aneurysms. Neurosurgery. 1991 Jul;29(1):83–88. doi: 10.1097/00006123-199107000-00014. [DOI] [PubMed] [Google Scholar]
- Friedman W. A., Kaplan B. L., Day A. L., Sypert G. W., Curran M. T. Evoked potential monitoring during aneurysm operation: observations after fifty cases. Neurosurgery. 1987 May;20(5):678–687. doi: 10.1227/00006123-198705000-00002. [DOI] [PubMed] [Google Scholar]
- Grundy B. L., Nelson P. B., Lina A., Heros R. C. Monitoring of cortical somatosensory evoked potentials to determine the safety of sacrificing the anterior cerebral artery. Neurosurgery. 1982 Jul;11(1 Pt 1):64–67. doi: 10.1227/00006123-198207010-00014. [DOI] [PubMed] [Google Scholar]
- Hargadine J. R., Branston N. M., Symon L. Central conduction time in primate brain ischemia -- a study in baboons. Stroke. 1980 Nov-Dec;11(6):637–642. doi: 10.1161/01.str.11.6.637. [DOI] [PubMed] [Google Scholar]
- Jones T. H., Morawetz R. B., Crowell R. M., Marcoux F. W., FitzGibbon S. J., DeGirolami U., Ojemann R. G. Thresholds of focal cerebral ischemia in awake monkeys. J Neurosurg. 1981 Jun;54(6):773–782. doi: 10.3171/jns.1981.54.6.0773. [DOI] [PubMed] [Google Scholar]
- Lesnick J. E., Michele J. J., Simeone F. A., DeFeo S., Welsh F. A. Alteration of somatosensory evoked potentials in response to global ischemia. J Neurosurg. 1984 Mar;60(3):490–494. doi: 10.3171/jns.1984.60.3.0490. [DOI] [PubMed] [Google Scholar]
- Little J. R., Lesser R. P., Luders H. Electrophysiological monitoring during basilar aneurysm operation. Neurosurgery. 1987 Mar;20(3):421–427. doi: 10.1227/00006123-198703000-00011. [DOI] [PubMed] [Google Scholar]
- Manninen P. H., Patterson S., Lam A. M., Gelb A. W., Nantau W. E. Evoked potential monitoring during posterior fossa aneurysm surgery: a comparison of two modalities. Can J Anaesth. 1994 Feb;41(2):92–97. doi: 10.1007/BF03009798. [DOI] [PubMed] [Google Scholar]
- McPherson R. W., Niedermeyer E. F., Otenasek R. J., Hanley D. F. Correlation of transient neurological deficit and somatosensory evoked potentials after intracranial aneurysm surgery. Case report. J Neurosurg. 1983 Jul;59(1):146–149. doi: 10.3171/jns.1983.59.1.0146. [DOI] [PubMed] [Google Scholar]
- Mizoi K., Yoshimoto T. Permissible temporary occlusion time in aneurysm surgery as evaluated by evoked potential monitoring. Neurosurgery. 1993 Sep;33(3):434–440. doi: 10.1227/00006123-199309000-00013. [DOI] [PubMed] [Google Scholar]
- Momma F., Wang A. D., Symon L. Effects of temporary arterial occlusion on somatosensory evoked responses in aneurysm surgery. Surg Neurol. 1987 Apr;27(4):343–352. doi: 10.1016/0090-3019(87)90009-7. [DOI] [PubMed] [Google Scholar]
- Morawetz R. B., DeGirolami U., Ojemann R. G., Marcoux F. W., Crowell R. M. Cerebral blood flow determined by hydrogen clearance during middle cerebral artery occlusion in unanesthetized monkeys. Stroke. 1978 Mar-Apr;9(2):143–149. doi: 10.1161/01.str.9.2.143. [DOI] [PubMed] [Google Scholar]
- Schramm J., Koht A., Schmidt G., Pechstein U., Taniguchi M., Fahlbusch R. Surgical and electrophysiological observations during clipping of 134 aneurysms with evoked potential monitoring. Neurosurgery. 1990 Jan;26(1):61–70. doi: 10.1097/00006123-199001000-00009. [DOI] [PubMed] [Google Scholar]
- Symon L., Crockard H. A., Dorsch N. W., Branston N. M., Juhasz J. Local cerebral blood flow and vascular reactivity in a chronic stable stroke in baboons. Stroke. 1975 Sep-Oct;6(5):482–492. doi: 10.1161/01.str.6.5.482. [DOI] [PubMed] [Google Scholar]
- Symon L., Momma F., Murota T. Assessment of reversible cerebral ischaemia in man: intraoperative monitoring of the somatosensory evoked response. Acta Neurochir Suppl (Wien) 1988;42:3–7. doi: 10.1007/978-3-7091-8975-7_1. [DOI] [PubMed] [Google Scholar]
- Symon L. The relationship between CBF, evoked potentials and the clinical features in cerebral ischaemia. Acta Neurol Scand Suppl. 1980;78:175–190. [PubMed] [Google Scholar]
- Symon L., Wang A. D., Costa e Silva I. E., Gentili F. Perioperative use of somatosensory evoked responses in aneurysm surgery. J Neurosurg. 1984 Feb;60(2):269–275. doi: 10.3171/jns.1984.60.2.0269. [DOI] [PubMed] [Google Scholar]
- Wagner W., Peghini-Halbig L., Mäurer J. C., Perneczky A. Intraoperative SEP monitoring in neurosurgery around the brain stem and cervical spinal cord: differential recording of subcortical components. J Neurosurg. 1994 Aug;81(2):213–220. doi: 10.3171/jns.1994.81.2.0213. [DOI] [PubMed] [Google Scholar]