Introduction: Removal of brainstem cavernous malformations is one of the most difficult procedures in neurosurgery. Intraoperative monitoring is used to avoid impending damage to these highly eloquent structures. However, data of neurophysiological monitoring during these procedures is lacking.
Methods: Consecutive patients with brainstem cavernous malformations who underwent surgical removal from June 2007 to December 2012 were retrospectively analyzed. Transcranial Motor evoked potentials (MEP) and somatosensory evoked potentials (SSEP) were performed in all cases. The monitoring data were reviewed and related to new postoperative motor deficit and postoperative imaging. Clinical outcomes were assessed during follow-up.
Results: 19 consecutive cases of brain stem cavernomas were identified. MEP and SSEP Monitoring was successful in 18 cases (94%). In 13 (73%) of all cases, MEP and SSEP were stable throughout the operation, but 5 patients (28%) developed a new neurological deficit. In 4 cases (22%) MEP and SSEP were permanently lost, but only one patient had a permanent new neurological deficit. In one case MEP and SSEP were temporary lost and the patients did not develop any new neurological deficits.
Conclusions: Continuous MEP and SSEP monitoring do not provide sufficient monitoring during brainstem cavernous malformations surgery as high rates of false positive and false negative results are encountered. Further development in this area is still needed.
Patient Care: This study could show the limitations for safe resection of brainstem cavernous malformations
Learning Objectives: By the conclusion of this session, participants should be able to describe the importance of intraoperative monitoring during resection of brainstem cavernous malformations.