Intraoperative Motor Mapping of the Cerebral Peduncle during Resection of a Midbrain Cavernous Malformation: Technical Case Report

2005 ◽  
Vol 56 (suppl_4) ◽  
pp. ONS-E439-ONS-E439 ◽  
Author(s):  
Alfredo Quiñones-Hinojosa ◽  
Russ Lyon ◽  
Rose Du ◽  
Michael T. Lawton

Abstract OBJECTIVE AND IMPORTANCE: Brainstem cavernous malformations that seem to come to a pial or ependymal surface on preoperative magnetic resonance imaging studies may, in fact, be covered by an intact layer of neural tissue. For cavernous malformations in the cerebral peduncle, intraoperative stimulation mapping with a miniaturized probe can determine whether this overlying tissue harbors fibers in the corticospinal tract. In addition, intermittent monitoring with transcranial motor evoked potentials (TcMEPs) helps to protect this vital pathway during resection of the lesion. CLINICAL PRESENTATION: A 20-year-old woman collapsed after a cavernous malformation in the left cerebral peduncle hemorrhaged into the pons, midbrain, and thalamus. She presented with right hemiparesis and left oculomotor palsy. INTERVENTION: The cavernous malformation was completely resected through a left orbitozygomatic craniotomy and transsylvian approach. Stimulation mapping of the cerebral peduncle with a Kartush probe (Medtronic Xomed, Inc., Jacksonville, FL) identified the corticospinal tract lateral to the lesion, and a layer of tissue over the lesion harbored no motor fibers. TcMEP monitoring helped to guide the resection, with increased voltage thresholds and altered waveform morphologies indicating transient impaired motor conduction. All TcMEP changes returned to baseline by the end of the procedure, and the patient's hemiparesis improved after surgery. CONCLUSION: Stimulation mapping of the corticospinal tract and intermittent TcMEPs is a safe and simple surgical adjunct. Expanded monitoring of the motor pathway during the resection of cerebral peduncle cavernous malformations may improve the safety of these operations.

2020 ◽  
Vol 132 (1) ◽  
pp. 265-271
Author(s):  
Ridzky Firmansyah Hardian ◽  
Tetsuya Goto ◽  
Yu Fujii ◽  
Kohei Kanaya ◽  
Tetsuyoshi Horiuchi ◽  
...  

OBJECTIVEThe aim of this study was to predict postoperative facial nerve function during pontine cavernous malformation surgery by monitoring facial motor evoked potentials (FMEPs).METHODSFrom 2008 to 2017, 10 patients with pontine cavernous malformations underwent total resection via the trans–fourth ventricle floor approach with FMEP monitoring. House-Brackmann grades and Karnofsky Performance Scale (KPS) scores were obtained pre- and postoperatively. The surgeries were performed using one of 2 safe entry zones into the brainstem: the suprafacial triangle and infrafacial triangle approaches. Six patients underwent the suprafacial triangle approach, and 4 patients underwent the infrafacial triangle approach. A cranial peg screw electrode was used to deliver electrical stimulation for FMEP by a train of 4 or 5 pulse anodal constant current stimulation. FMEP was recorded from needle electrodes on the ipsilateral facial muscles and monitored throughout surgery by using a threshold-level stimulation method.RESULTSFMEPs were recorded and analyzed in 8 patients; they were not recorded in 2 patients who had severe preoperative facial palsy and underwent an infrafacial triangle approach. Warning signs appeared in all patients who underwent the suprafacial triangle approach. However, after temporarily stopping the procedures, FMEP findings during surgery showed recovery of the thresholds. FMEPs in patients who underwent the infrafacial triangle approach were stable during the surgery. House-Brackmann grades were unchanged postoperatively in all patients. Postoperative KPS scores improved in 3 patients, decreased in 1, and remained the same in 6 patients.CONCLUSIONSFMEPs can be used to monitor facial nerve function during surgery for pontine cavernous malformations, especially when the suprafacial triangle approach is performed.


2019 ◽  
Vol 1 (1) ◽  
pp. V26
Author(s):  
Peyton L. Nisson ◽  
Robert T. Wicks ◽  
Xiaochun Zhao ◽  
Whitney S. James ◽  
David Xu ◽  
...  

Cavernous malformations of the brain are low-flow vascular lesions that have a propensity to hemorrhage. Extensive surgical approaches are often required for operative cure of deep-seated lesions. A 23-year-old female presented with a cavernous malformation of the left posterior insula with surrounding hematoma measuring up to 3 cm. A minimally invasive (mini-)pterional craniotomy with a transsylvian approach was selected. Endoscopic assistance was utilized to confirm complete resection of the lesion. The minipterional craniotomy is a minimally invasive approach that provides optimal exposure for sylvian fissure dissection and resection of many temporal and insular lesions.The video can be found here: https://youtu.be/9z6_EhU6lxs.


2018 ◽  
Vol 16 (4) ◽  
pp. E113-E113
Author(s):  
Justin R Mascitelli ◽  
Sirin Gandhi ◽  
Claudio Cavallo ◽  
Michael J Nanaszko ◽  
Ernest J Wright ◽  
...  

Abstract Brainstem cavernous malformations (CMs) account for 15% to 18% of all intracranial CMs1 and 13% of all cerebrovascular pathology in the posterior fossa.1,2 This video demonstrates the resection of a pontomesencephalic CM through a pretemporal approach through the oculomotor-tentorial triangle (OTT).3 A 49-yr-old woman presented with an acute onset of left hemiparesis, diplopia, vertigo, partial oculomotor, and facial palsy. Neuroimaging revealed a 25-mm diameter right pontomesencephalic CM with evidence of prior hemorrhage. Institutional Review Board approval and patient consent were obtained for surgery. A right orbitozygomatic craniotomy was performed, and the lesion was exposed through a pretemporal-transsylvian approach. After a wide Sylvian fissure split, the oculomotor nerve (CN III) was dissected away from the temporal lobe, and the temporal lobe was mobilized posteriorly to access the OTT. The posterior cerebral and superior cerebellar arteries were visualized in this triangle, and the cerebral peduncle and the CM were accessed deep to these arteries. After hematoma evacuation, the CM was resected in a piece-meal fashion using an intracapsular technique. Postoperative imaging confirmed the gross total resection of the lesion. The patient had persistent right CN III palsy and a slight worsening of left hemiparesis, which had resolved completely at the 6-mo follow-up. The OTT provides access to the upper ventrolateral pontomesencephalic area.3 This triangular surgical workspace is entered through a pretemporal-transsylvian corridor and widened with posterior temporal lobe retraction. The OTT is an important working space for accessing midbrain and upper pontine CMs posterolateral to CN III.


2019 ◽  
Vol 1 (1) ◽  
pp. V11
Author(s):  
André Bortolon Bissoli ◽  
Aderaldo Costa Alves Junior ◽  
Pedro Tadao Hamamoto Filho ◽  
Marco Antonio Zanini

Cavernous malformations (CVMs) located in the thalamus are uncommon. However, they pose difficulties for resection because of their close proximity to eloquent areas of the brain and vascular structures, and all surgical corridors to access them are narrow. In this video, we report the case of a 19-year-old woman who presented with a long-standing history of right hemiparesis with recent deterioration. MRI revealed a large CVM located in the left thalamus, with signs of recent hemorrhage extending to the left cerebral peduncle. Resection was achieved with a paramedian contralateral supracerebellar infratentorial approach in a semisitting position, with an uneventful postoperative course.The video can be found here: https://youtu.be/Arvu52FkHOE.


2015 ◽  
Vol 123 (2) ◽  
pp. 301-306 ◽  
Author(s):  
Ehab Shiban ◽  
Sandro M. Krieg ◽  
Thomas Obermueller ◽  
Maria Wostrack ◽  
Bernhard Meyer ◽  
...  

OBJECT Resection of a motor eloquent lesion has become safer because of intraoperative neurophysiological monitoring (IOM). Stimulation of subcortical motor evoked potentials (scMEPs) is increasingly used to optimize patient safety. So far, scMEP stimulation has been performed intermittently during resection of eloquently located lesions. Authors of the present study assessed the possibility of using a resection instrument for continuous stimulation of scMEPs. METHODS An ultrasonic surgical aspirator was attached to an IOM stimulator and was used as a monopolar subcortical stimulation probe. The effect of the aspirator’s use at different ultrasound power levels (0%, 25%, 50%, 75%, and 100%) on stimulation intensity was examined in a saline bath. Afterward monopolar stimulation with the surgical aspirator was used during the resection of subcortical lesions in the vicinity of the corticospinal tract in 14 patients in comparison with scMEP stimulation via a standard stimulation electrode. During resection, the stimulation current at which an MEP response was still measurable with subcortical stimulation using the surgical aspirator was compared with the corresponding stimulation current needed using a standard monopolar subcortical stimulation probe at the same location. RESULTS The use of ultrasound at different energy levels did result in a slight but irrelevant increase in stimulation energy via the tip of the surgical aspirator in the saline bath. Stimulation of scMEPs using the surgical aspirator or monopolar probe was successful and almost identical in all patients. One patient developed a new permanent neurological deficit. Transient new postoperative paresis was observed in 28% (4 of 14) of cases. Gross-total resection was achieved in 64% (9 of 14) cases and subtotal resection (> 80% of tumor mass) in 35% (5 of 14). CONCLUSIONS Continuous motor mapping using subcortical stimulation via a surgical aspirator, in comparison with the sequential use of a standard monopolar stimulation probe, is a feasible and safe method without any disadvantages. Compared with the standard probe, the aspirator offers continuous information on the distance to the corticospinal tract.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Davide Giampiccolo ◽  
Cristiano Parisi ◽  
Pietro Meneghelli ◽  
Vincenzo Tramontano ◽  
Federica Basaldella ◽  
...  

Abstract Muscle motor-evoked potentials are commonly monitored during brain tumour surgery in motor areas, as these are assumed to reflect the integrity of descending motor pathways, including the corticospinal tract. However, while the loss of muscle motor-evoked potentials at the end of surgery is associated with long-term motor deficits (muscle motor-evoked potential-related deficits), there is increasing evidence that motor deficit can occur despite no change in muscle motor-evoked potentials (muscle motor-evoked potential-unrelated deficits), particularly after surgery of non-primary regions involved in motor control. In this study, we aimed to investigate the incidence of muscle motor-evoked potential-unrelated deficits and to identify the associated brain regions. We retrospectively reviewed 125 consecutive patients who underwent surgery for peri-Rolandic lesions using intra-operative neurophysiological monitoring. Intraoperative changes in muscle motor-evoked potentials were correlated with motor outcome, assessed by the Medical Research Council scale. We performed voxel–lesion–symptom mapping to identify which resected regions were associated with short- and long-term muscle motor-evoked potential-associated motor deficits. Muscle motor-evoked potentials reductions significantly predicted long-term motor deficits. However, in more than half of the patients who experienced long-term deficits (12/22 patients), no muscle motor-evoked potential reduction was reported during surgery. Lesion analysis showed that muscle motor-evoked potential-related long-term motor deficits were associated with direct or ischaemic damage to the corticospinal tract, whereas muscle motor-evoked potential-unrelated deficits occurred when supplementary motor areas were resected in conjunction with dorsal premotor regions and the anterior cingulate. Our results indicate that long-term motor deficits unrelated to the corticospinal tract can occur more often than currently reported. As these deficits cannot be predicted by muscle motor-evoked potentials, a combination of awake and/or novel asleep techniques other than muscle motor-evoked potentials monitoring should be implemented.


Author(s):  
Prajwal Ghimire ◽  
Jose Pedro Lavrador ◽  
Asfand Baig Mirza ◽  
Noemia Pereira ◽  
Hannah Keeble ◽  
...  

AbstractPenfield’s motor homunculus describes a caricaturised yet useful representation of the map of various body parts on the pre-central cortex. We propose a supplemental map of the clinically represented areas of human body in pre-central cortex and a novel subcortical corticospinal tract map. We believe this knowledge is essential for safe surgery in patients with eloquent brain lesions. A single-institution retrospective cohort study of patients who underwent craniotomy for motor eloquent lesions with intraoperative motor neuromonitoring (cortical and subcortical) between 2015 and 2020 was performed. All positive cortical and subcortical stimulation points were taken into account and cartographic maps were produced to demonstrate cortical and subcortical areas of motor representation and their configuration. A literature review in PubMed was performed. One hundred and eighty consecutive patients (58.4% male, 41.6% female) were included in the study with 81.6% asleep and 18.4% awake craniotomies for motor eloquent lesions (gliomas 80.7%, metastases 13.8%) with intraoperative cortical and subcortical motor mapping. Based on the data, we propose a supplemental clinical cortical and a novel subcortical motor map to the original Penfield’s motor homunculus, including demonstration of localisation of intercostal muscles both in the cortex and subcortex which has not been previously described. The supplementary clinical cortical and novel subcortical motor maps of the homunculus presented here have been derived from a large cohort of patients undergoing direct cortical and subcortical brain mapping. The information will have direct relevance for improving the safety and outcome of patients undergoing resection of motor eloquent brain lesions.


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