Motor-Evoked Potentials in Cerebral Aneurysm Surgery

Object The authors in this study evaluated muscle motor evoked potentials (MMEPs) elicited by transcranial electrical stimulation (TES) and direct cortical stimulation as a means of monitoring during cerebral aneurysm surgery. The analysis focused on the value and frequencies of any intraoperative changes and their correlation to the postoperative motor status. Methods One hundred nineteen patients undergoing surgery for 148 cerebral aneurysms were included in the study. Muscle motor evoked potentials were elicited by a train of five constant-current anodal stimuli with an individual pulse duration of 0.5 msec and a stimulation rate of 2 Hz. Stimulation intensity was up to 240 mA for TES and up to 33 mA for direct cortical stimulation. The MMEPs were continuously recorded from the abductor pollicis brevis and tibialis anterior muscles bilaterally and from the biceps brachii and extensor digitorum communis muscles contralateral to the surgical side. The motor status was evaluated immediately after surgery and 7 days later. In 97% of the patients MMEPs were recordable for continuous neurophysiological monitoring of the vascular territory of interest throughout the surgery. In 14 patients significant intraoperative MMEP changes occurred, resulting in a transient motor deficit in one patient and a permanent motor deficit in six. The permanent loss of MMEPs in three patients was followed by a permanent severe motor deficit in one patient and severe clinical deterioration in the other two. Conclusions Data in this study demonstrated that MMEPs are a useful means of intraoperative neurophysiological monitoring of motor pathway integrity and predicting postoperative motor status. The intraoperative loss of MMEPs reliably predicts both severe and permanent postoperative motor deficits.

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The Significance of Intraoperative Monitoring of Muscle Motor Evoked Potentials during Unruptured Large and Giant Cerebral Aneurysm Surgery

Neurologia medico-chirurgica ◽

10.2176/nmc.oa.2013-0001 ◽

2014 ◽

Vol 54 (3) ◽

pp. 180-188 ◽

Cited By ~ 9

Author(s):

Seiji TAKEBAYASHI ◽

Hiroyasu KAMIYAMA ◽

Katsumi TAKIZAWA ◽

Tohru KOBAYASHI ◽

Norihiro SAITOH

Keyword(s):

Evoked Potentials ◽

Cerebral Aneurysm ◽

Intraoperative Monitoring ◽

Motor Evoked Potentials ◽

Aneurysm Surgery ◽

Giant Cerebral Aneurysm

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P180 Intraoperative monitoring of motor evoked potentials reduces the incidence of paraplegia after thoraco-abdominal aortic aneurysm surgery

Clinical Neurophysiology ◽

10.1016/s1388-2457(08)60451-4 ◽

2008 ◽

Vol 119 ◽

pp. S116

Author(s):

Birger Johnsen ◽

Niels Christian Melsen ◽

Jesper Laustsen ◽

Bent Skov Jensen

Keyword(s):

Abdominal Aortic Aneurysm ◽

Aortic Aneurysm ◽

Evoked Potentials ◽

Intraoperative Monitoring ◽

Motor Evoked Potentials ◽

Aneurysm Surgery ◽

Abdominal Aortic ◽

Aortic Aneurysm Surgery

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Transient Augmentation of Intraoperative Motor Evoked Potentials During Middle Cerebral Artery Aneurysm Surgery

World Neurosurgery ◽

10.1016/j.wneu.2019.06.004 ◽

2019 ◽

Vol 130 ◽

pp. e127-e132

Author(s):

Pritam Gurung ◽

Yasushi Motoyama ◽

Tsunenori Takatani ◽

Yoshiaki Takamura ◽

Yasuhiro Takeshima ◽

...

Keyword(s):

Evoked Potentials ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

Motor Evoked Potentials ◽

Artery Aneurysm ◽

Aneurysm Surgery ◽

Middle Cerebral Artery Aneurysm ◽

Cerebral Artery Aneurysm

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Monitoring of motor evoked potentials compared with somatosensory evoked potentials and microvascular Doppler ultrasonography in cerebral aneurysm surgery

Journal of Neurosurgery ◽

10.3171/jns.2004.100.3.0389 ◽

2004 ◽

Vol 100 (3) ◽

pp. 389-399 ◽

Cited By ~ 148

Author(s):

Georg Neuloh ◽

Johannes Schramm

Keyword(s):

Clinical Outcome ◽

Evoked Potentials ◽

Somatosensory Evoked Potentials ◽

Doppler Ultrasonography ◽

Motor Evoked Potentials ◽

Motor Impairment ◽

Aneurysm Surgery ◽

Vessel Occlusion ◽

Content Type ◽

Fine Print

Object. The aims of this study were to compare the efficiency of motor evoked potentials (MEPs), somatosensory evoked potentials (SSEPs), and microvascular Doppler ultrasonography (MDU) in the detection of impending motor impairment from subcortical ischemia in aneurysm surgery; to determine their sensitivity for specific intraoperative events; and to compare their impact on the surgical strategy used. Methods. Motor evoked potentials, SSEPs, and MDU were monitored during 100 operations for 129 aneurysms in 95 patients. Intraoperative events, monitoring results, and clinical outcome were correlated in a prospective observational design. Motor evoked potentials indicated inadequate temporary clipping, inadvertent occlusion, inadequate retraction, vasospasm, or compromise to perforating vessels in 21 of 33 instances and deteriorated despite stable SSEPs in 18 cases. Microvascular Doppler ultrasonography revealed inadvertent vessel occlusion in eight of 10 cases and insufficient clipping in four of four cases. Stable evoked potentials (EPs) allowed safe, permanent vessel occlusion or narrowing despite reduced flow on MDU in five cases. Two patients sustained permanent and 10 showed transient new weakness, which had been detected by SSEPs in two of 12 patients and MEPs in 10 of 11 monitored cases. The surgical strategy was directly altered in 33 instances: by MEPs in 16, SSEPs in four, and MDU in 13. Conclusions. Monitoring of MEPs is superior to SSEP monitoring and MDU in detecting motor impairment, particularly that from subcortical ischemia. Microvascular Doppler ultrasonography is superior to EP monitoring in detecting inadvertent vessel occlusion, but cannot assess remote collateral flow. Motor evoked potentials are most sensitive to all other intraoperative conditions and have a direct influence on the course of surgery in the majority of events. A controlled study design is required to confirm the positive effect of monitoring on clinical outcome in aneurysm surgery.

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