Awake Microvascular Decompression for Trigeminal Neuralgia: Concept and Initial Results.

BACKGROUND: In this initial series, we evaluated the use of microvascular decompression (MVD) under an awake anesthesia protocol ("awake" MVD) to assess whether intraoperative pain evaluation can identify and mitigate insufficient decompression of the trigeminal nerve, improving surgical outcomes, and possibly expand the indications of MVD in patients with comorbidities that would preclude the use of general endotracheal anesthesia (GEA). METHODS: An Institutional Review Board-approved prospective study of 10 consecutive adults who underwent MVD for trigeminal neuralgia (TN) was conducted. The primary outcome measure was postoperative TN pain quantified on the Barrow Neurological Institute (BNI) Pain Severity Scale. RESULTS: The median patient age was 65.5 years, with a female:male ratio of 6:4. All 10 patients tolerated the procedure well and did not require GEA intraoperatively or postoperatively. Nine patients had a successful surgical outcome (BNI score I, n = 5; BNI score II, n = 4). One patient did not have pain relief (BNI score IV). This same patient also developed a pseudomeningocele, which was the sole surgical complication observed in this series. One patient experienced recurrence of pain at 11 months, with BNI score increasing from I to II. The median duration of follow-up was 16.5 months. Two patients did not experienced resolution of evoked pain during intraoperative awake testing following decompression. Further intraoperative exploration revealed secondary offending vessels that were subsequently decompressed, leading to resolution of pain. CONCLUSIONS: Intraoperative awake testing for treatment efficacy may increase the success rate of MVD by rapidly identifying and mitigating insufficient cranial nerve V decompression.

Awake High-Flow Extracranial to Intracranial Bypass for Complex Cerebral Aneurysms: Institutional Clinical Trial Results.

OBJECTIVE: Assess the potential added benefit to patient outcomes of "awake" neurological testing when compared with standard neurophysiologic testing performed under general endotracheal anesthesia. METHODS: Prospective study of 30 consecutive adult patients who underwent awake high flow extracranial to intracranial (HFEC-IC) bypass. Clinical neurological and neurophysiologic findings were recorded. Primary outcome measures were the incidence of stroke/cerebrovascular accident (CVA), length of stay, discharge to rehabilitation, 30-day modified Rankin scale score, and death. An analysis was also performed of a retrospective control cohort (n = 110 patients who underwent HFEC-IC for internal carotid artery (ICA) aneurysms under standard general endotracheal anesthesia). RESULTS: Five patients (16.6%) developed clinical awake neurological changes (4, contralateral hemiparesis; 1, ipsilateral visual changes) during the 10-minute ICA occlusion test. These patients had 2 kinks in the graft, 1 vasospasm, 1 requiring reconstruction of the distal anastomosis, and 1 developed blurring of vision that reversed after the removal of the distal permanent clip on the ICA. Three of these 5 patients had asynchronous clinical "awake" neurological and neurophysiologic changes. Two patients (7%) developed CVA. Median length of stay was 4 days. Twenty-eight of 30 patients were discharged to home. Median modified Rankin scale score was 1. There were no deaths in this series. Absolute risk reduction in the awake craniotomy group (n = 30) relative to control retrospective group (n = 110) was 7% for CVA, 9% for discharge to rehabilitation, and 10% for graft patency. CONCLUSIONS: Temporary ICA occlusion during HFEC-IC bypass for ICA aneurysms in conjunction with awake intraoperative clinical testing was effective in detecting a subset of patients (n = 3, 10%) in whom neurological deficit was not detected by neurophysiologic monitoring alone.

"Awake" clipping of cerebral aneurysms: report of initial series.

OBJECTIVE Risk of ischemia during aneurysm surgery is significantly related to temporary clipping time and final clipping that might incorporate a perforator. In this study, the authors attempted to assess the potential added benefit to patient outcomes of "awake" neurological testing when compared with standard neurophysiological testing performed under general anesthesia. The procedure is performed after the induction of conscious sedation, and for the neurological testing, the patient is fully awake. METHODS The authors conducted an institutional review board-approved prospective study of clipping unruptured intracranial aneurysms (UIAs) in 30 consecutive adult patients who underwent awake clipping. The end points were the incidence of stroke/cerebrovascular accident (CVA), death, discharge to a long-term facility, length of stay, and 30-day modified Rankin Scale score. All clinical and neurophysiological intraoperative monitoring data were recorded. RESULTS The median patient age was 52 years (range 27-63 years); 19 (63%) female and 11 (37%) male patients were included. Twenty-seven (90%) aneurysms were anterior, and 3 (10%) were posterior circulation aneurysms. Five (17%) had been coiled previously, 3 (10%) had been clipped previously, 2 (7%) were partially calcified, and 2 (7%) were fusiform aneurysms. Three patients developed synchronous clinical neurological and neurophysiological changes during temporary clipping with consequent removal of the temporary clip and reversal of those clinical and neurophysiological changes. Three patients developed asynchronous clinical neurological and neurophysiological changes. These 3 patients developed hemiparesis without changes in neurophysiological monitoring results. One patient developed linked clinical neurological and neurophysiological changes during final clipping that were not reversed by reapplication of the clip, and the patient had a CVA. Four patients with internal carotid artery ophthalmic segment aneurysms underwent visual testing with final clipping, and 1 of these patients required repositioning of the clip. Three patients who required permanent occlusion of a vessel as part of their aneurysm treatment underwent a 10-minute intraoperative clinical respective-vessel test occlusion. The median length of stay was 3 days (range 1-5 days). The median modified Rankin Scale score was 1 (range 0-3). All of the patients were discharged to home from the hospital except for 1 who developed a CVA and was discharged to a rehabilitation facility. There were no deaths in this series. CONCLUSIONS The 3 patients who developed neurological deterioration without a concomitant neurophysiological finding during temporary clipping revealed a potential advantage of awake aneurysm surgery (i.e., in decreasing the risk of ischemic injury).