Intraoperative Neurophysiological Monitoring in Posterior Fossa Surgery

2015 ◽  
pp. 239-262 ◽  
Author(s):  
Francesco Sala ◽  
Pasquale Gallo ◽  
Vincenzo Tramontano ◽  
Massimo Gerosa
Keyword(s):  
Posterior Fossa ◽  
Intraoperative Neurophysiological Monitoring ◽  
Neurophysiological Monitoring ◽  
Posterior Fossa Surgery

scholarly journals NS-01PEDIATRIC INTRAOPERATIVE NEUROPHYSIOLOGICAL MONITORING IN POSTERIOR FOSSA SURGERY

2016 ◽  
Vol 18 (suppl 3) ◽  
pp. iii127.1-iii127
Author(s):  
Franco Randi ◽  
Andrea Carai ◽  
Gionatan Amante ◽  
Alessandro De Benedictis ◽  
Raffaella Messina ◽  
...  
Keyword(s):  
Posterior Fossa ◽  
Intraoperative Neurophysiological Monitoring ◽  
Neurophysiological Monitoring ◽  
Posterior Fossa Surgery

scholarly journals Intraoperative neurophysiological monitoring during resection of infratentorial lesions: the surgeon's view

2017 ◽  
Vol 126 (1) ◽  
pp. 281-288 ◽  
Author(s):  
Philipp J. Slotty ◽  
Amr Abdulazim ◽  
Kunihiko Kodama ◽  
Mani Javadi ◽  
Daniel Hänggi ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Posterior Fossa ◽  
Auditory Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Neurological Deficits ◽  
Neurophysiological Monitoring ◽  
Posterior Fossa Surgery ◽  
Lesion Location ◽  
Crucial Information ◽  
Free Running

OBJECTIVE Methods of choice for neurophysiological intraoperative monitoring (IOM) within the infratentorial compartment mostly include early brainstem auditory evoked potentials, free-running electromyography, and direct cranial nerve (CN) stimulation. Long-tract monitoring with somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) is rarely used. This study investigated the incidence of IOM alterations during posterior fossa surgery stratified for lesion location. METHODS Standardized CN and SEP/MEP IOM was performed in 305 patients being treated for various posterior fossa pathologies. The IOM data were correlated with lesion locations and histopathological types as well as other possible confounding factors. RESULTS Alterations in IOM were observed in 158 of 305 cases (51.8%) (CN IOM alterations in 130 of 305 [42.6%], SEP/MEP IOM alterations in 43 of 305 [14.0%]). In 15 cases (4.9%), simultaneous changes in long tracts and CNs were observed. The IOM alterations were followed by neurological sequelae in 98 of 305 cases (32.1%); 62% of IOM alterations resulted in neurological deficits. Sensitivity and specificity for detection of CN deficits were 98% and 77%, respectively, and 95% and 85%, respectively, for long-tract deficits. Regarding location, brainstem and petroclival lesions were closely associated with concurrent CN IOM and SEP/MEP alterations. CONCLUSIONS The incidence of IOM alterations during surgery in the posterior fossa varied widely between different lesion locations and histopathological types. This analysis provides crucial information on the necessity of IOM in different surgical settings. Because MEP/SEP and CN IOM alterations were commonly observed during posterior fossa surgery, the authors recommend the simultaneous use of both modalities based on lesion location.

scholarly journals Feasibility of cerebello-cortical stimulation for intraoperative neurophysiological monitoring of cerebellar mutism

2021 ◽  
Author(s):  
Davide Giampiccolo ◽  
Federica Basaldella ◽  
Andrea Badari ◽  
Giovanna Maddalena Squintani ◽  
Luigi Cattaneo ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Test Stimulus ◽  
Posterior Fossa ◽  
Motor Evoked Potentials ◽  
Significant Inhibition ◽  
Neurophysiological Monitoring ◽  
Posterior Fossa Surgery ◽  
Cerebellar Mutism ◽  
Motor Cortex Excitability ◽  
Electrical Conditioning

Abstract Background Cerebellar mutism can occur in a third of children undergoing cerebellar resections. Recent evidence proposes it may arise from uni- or bilateral damage of cerebellar efferents to the cortex along the cerebello-dento-thalamo-cortical pathway. At present, no neurophysiological procedure is available to monitor this pathway intraoperatively. Here, we specifically aimed at filling this gap. Methods We assessed 10 patients undergoing posterior fossa surgery using a conditioning-test stimulus paradigm. Electrical conditioning stimuli (cStim) were delivered to the exposed cerebellar cortex at interstimulus intervals (ISIs) of 8–24 ms prior to transcranial electric stimulation of the motor cortex, which served as test stimulus (tStim). The variation of motor-evoked potentials (MEP) to cStim + tStim compared with tStim alone was taken as a measure of cerebello-cortical connectivity. Results cStim alone did not produce any MEP. cStim preceding tStim produced a significant inhibition at 8 ms (p < 0.0001) compared with other ISIs when applied to the lobules IV-V-VI in the anterior cerebellum and the lobule VIIB in the posterior cerebellum. Mixed effects of decrease and increase in MEP amplitude were observed in these areas for longer ISIs. Conclusions The inhibition exerted by cStim at 8 ms on the motor cortex excitability is likely to be the product of activity along the cerebello-dento-thalamo-cortical pathway. We show that monitoring efferent cerebellar pathways to the motor cortex is feasible in intraoperative settings. This study has promising implications for pediatric posterior fossa surgery with the aim to preserve the cerebello-cortical pathways and thus prevent cerebellar mutism.

Posterior Fossa

2019 ◽  
Author(s):  
Talia S. Vogel ◽  
Penny P. Liu
Keyword(s):  
Posterior Fossa ◽  
Preoperative Evaluation ◽  
Cranial Nerves ◽  
Air Embolism ◽  
Neurophysiological Monitoring ◽  
Posterior Fossa Surgery ◽  
Neurophysiologic Monitoring ◽  
Venous Air Embolism ◽  
Brainstem Stroke ◽  
Air Embolus

The posterior fossa houses essential brainstem nuclei, cranial nerves, cerebral vasculature, and mechanisms for cerebrospinal fluid drainage. Anesthetic considerations for posterior fossa surgery include thorough preoperative evaluation, intraoperative monitoring, and anesthetic planning to allow neurophysiological monitoring. Careful positioning is imperative to optimize surgical conditions and to risk stratify patients for complications, including venous air embolus. Venous air embolus is a common complication of posterior fossa surgery given the plentitude of venous channels in the posterior fossa, and rapid recognition is key to managing this complication.  Posterior fossa surgery also has a number of other known complications including postoperative apnea, prolonged ventilation, and possible brainstem stroke.  This review contains 4 tables, 1 video, and 31 references. Keywords: Posterior fossa surgery, Brainstem surgery, Neuroanesthesiology, Venous air embolism/embolus, Sitting craniotomy, Prone craniotomy, Transesophageal echocardiogram, Neurophysiologic monitoring

Continuous Intraoperative Neurophysiological Monitoring of the Motor Pathways Using Depth Electrodes During Surgical Resection of an Epileptogenic Lesion: A Novel Technique

2021 ◽  
Author(s):  
Denise F Chen ◽  
Jon T Willie ◽  
David Cabrera ◽  
Katie L Bullinger ◽  
Ioannis Karakis
Keyword(s):  
Motor Cortex ◽  
Surgical Resection ◽  
Radiation Necrosis ◽  
World Health ◽  
Intraoperative Neurophysiological Monitoring ◽  
Neurophysiological Monitoring ◽  
Epileptogenic Zone ◽  
Motor Pathways ◽  
Depth Electrodes ◽  
Epileptogenic Lesion

Abstract BACKGROUND AND IMPORTANCE Intraoperative neurophysiological monitoring of the motor pathways during epilepsy surgery is essential to safely achieve maximal resection of the epileptogenic zone. Motor evoked potential (MEP) recording is usually performed intermittently during resection using a handheld stimulator or continuously through an electrode array placed on the motor cortex. We present a novel variation of continuous MEP acquisition through previously implanted depth electrodes in the perirolandic cortex. CLINICAL PRESENTATION A 60-yr-old woman with a history of a left frontal meningioma (World Health Organization [WHO] grade II) treated with surgical resection and radiation presented with residual right hemiparesis and refractory epilepsy. Imaging demonstrated a perirolandic lesion with surrounding edema and mass effect in the prior surgical site, suspicious for radiation necrosis versus tumor recurrence. Presurgical electrocorticography (ECoG) with orthogonal, stereotactically implanted depth electrodes (stereoelectroencephalography [SEEG]) of the perirolandic cortex captured seizure onsets from the supplementary motor area (SMA) and primary motor cortex (PMC). The patient underwent a left frontal craniotomy for repeat resection and tissue diagnosis. Intraoperative ECoG and MEPs were obtained continuously with direct cortical stimulation through the indwelling SEEG electrodes in the PMC. Maximal resection was achieved with preservation of direct cortical MEPs and without deterioration of her baseline hemiparesis. Biopsy revealed radiation necrosis. At 30-mo follow-up, the patient had only rare seizures (Engel class IIB). CONCLUSION Intraoperative cortical MEP acquisition through implanted SEEG electrode arrays is a potentially safe and effective alternative approach to continuously monitor the motor pathways during the resection of a perirolandic epileptogenic lesion, without the need for surgical interruptions.

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