Hybrid Fluoroscopic and Neurophysiological Targeting of Responsive Neurostimulation of the Rolandic Cortex

Abstract BACKGROUND Precise targeting of cortical surface electrodes to epileptogenic regions defined by anatomic and electrophysiological guideposts remains a surgical challenge during implantation of responsive neurostimulation (RNS) devices. OBJECTIVE To describe a hybrid fluoroscopic and neurophysiological technique for targeting of subdural cortical surface electrodes to anatomic regions with limited direct visualization, such as the interhemispheric fissure. METHODS Intraoperative two-dimensional (2D) fluoroscopy was used to colocalize and align an electrode for permanent device implantation with a temporary in Situ electrode placed for extraoperative seizure mapping. Intraoperative phase reversal mapping technique was performed to distinguish primary somatosensory and motor cortex. RESULTS We applied these techniques to optimize placement of an interhemispheric strip electrode connected to a responsive neurostimulator system for detection and treatment of seizures arising from a large perirolandic cortical malformation. Intraoperative neuromonitoring (IONM) phase reversal technique facilitated neuroanatomic mapping and electrode placement. CONCLUSION In challenging-to-access anatomic regions, fluoroscopy and intraoperative neurophysiology can be employed to augment targeting of neuromodulation electrodes to the site of seizure onset zone or specific neurophysiological biomarkers of clinical interest while minimizing brain retraction.

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The Irritative Zone and Seizure Onset Zone in Acute ECOG: The Quest for Relevant Epileptogenic Tissue

Invasive Studies of the Human Epileptic Brain ◽

10.1093/med/9780198714668.003.0010 ◽

2018 ◽

pp. 120-130

Author(s):

André Palmini ◽

Eliseu Paglioli

Keyword(s):

Epilepsy Surgery ◽

Cost Effective ◽

Careful Analysis ◽

Cortical Surface ◽

Interictal Spikes ◽

Intracranial Eeg ◽

Seizure Onset Zone ◽

Cost Effective Approach ◽

Lesion Type ◽

Refractory Seizures

Acute intraoperative electrocorticography (ECoG) is a time-honoured technique to identify the relevant epileptogenic tissue (RET) and hence guide cortical resection to control medically refractory seizures. ECoG identifies the RET through careful analysis of pattern, morphology, frequency, and localization of interictal spikes recorded directly from the exposed cortical surface. Because the development and dissemination of chronic intracranial EEG recording techniques has put emphasis on ictal recordings (thus defining an ictal onset zone), acute ECoG is often considered unnecessary in surgical planning. The chapter describes limitations and advantages of acute ECoG to define the RET in comparison with more costly and risky procedures, particularly subdural grid and SEEG recording. Specifically, it shows how the integration of lesion type and sequentially recorded ECoG spikes during operation may provide a highly cost-effective approach to successful epilepsy surgery.

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Comparing Noninvasive Dense Array and Intracranial Electroencephalography for Localization of Seizures

Neurosurgery ◽

10.1227/01.neu.0000363721.06177.07 ◽

2010 ◽

Vol 66 (2) ◽

pp. 354-362 ◽

Cited By ~ 50

Author(s):

Mark D. Holmes ◽

Don M. Tucker ◽

Jason M. Quiring ◽

Shahin Hakimian ◽

John W. Miller ◽

...

Keyword(s):

Closed Head Injury ◽

Epileptic Seizures ◽

Electrode Placement ◽

Source Analysis ◽

Noninvasive Evaluation ◽

Dense Array ◽

Seizure Onset ◽

Seizure Onset Zone ◽

Intracranial Electrode ◽

Intracranial Electroencephalography

Abstract OBJECTIVE To compare the localization of the seizure onset zone estimated from ictal recordings with high spatial resolution, 256-channel scalp dense array electroencephalographic video long-term monitoring (LTM) with the aid of source analysis with that obtained from subsequent intracranial ictal recordings. METHODS Ten patients with medically refractory epilepsy, all surgical candidates, underwent intracranial LTM after standard noninvasive evaluation failed to provide adequate localizing information regarding ictal origins. Before invasive studies, all patients underwent dense array electroencephalographic LTM in which habitual clinical seizures were recorded for each patient. Source analysis was applied to ictal onsets. Intracranial electrode placement followed conventional guidelines, although the neurosurgeon was aware of the dense array electroencephalographic results. Patients ranged in age from 10 to 49 years (mean age, 24 y); 7 were male. Identified risk factors included closed head injury in 1 patient and childhood meningitis in another. No focal neurological signs were found in any patient. Magnetic resonance imaging findings were normal in 6 patients; 1 patient had cerebellar hypoplasia, 1 had right frontoparietal dysplasia, 1 had bilateral nonspecific white matter abnormalities, and 1 had bilateral cavernous angiomas. RESULTS Ictal onsets, based on invasive recordings, were in the mesiotemporal lobe (3 patients), lateroparietal (2 patients), mesioparietal (1 patient), laterofrontal (1 patient), superolateral frontocentral (1 patient), frontopolar (1 patient), and posteroinferior temporo-occipital neocortex (1 patient). Dense array electroencephalography localized ictal onsets to the same region as intracranial monitoring in 8 of 10 cases; invasive studies disclosed an additional ictal focus in 2 of these patients. Surgical resections were based only on intracranial electroencephalographic findings. CONCLUSION Dense array electroencephalography has the potential to assist in the noninvasive localization of epileptic seizures and to guide the placement of invasive electrodes for localizing seizure onset.

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Utility of a novel exoscope, ORBEYE, in gravity-assisted brain retraction surgery for midline lesions of the brain

Surgical Neurology International ◽

10.25259/sni_320_2021 ◽

2021 ◽

Vol 12 ◽

pp. 339

Author(s):

Noriyuki Kijima ◽

Manabu Kinoshita ◽

Masatoshi Takagaki ◽

Haruhiko Kishima

Keyword(s):

Brain Tumors ◽

Brain Lesions ◽

High Definition ◽

Ipsilateral Side ◽

Cavernous Malformations ◽

Awkward Position ◽

Neuronavigation System ◽

Interhemispheric Fissure ◽

Ergonomic Analysis ◽

Brain Retraction

Background: Midline brain lesions, such as falx meningioma, arteriovenous malformations, and cavernous malformations, are usually approached from the ipsilateral interhemispheric fissure. To this end, patients are positioned laterally with the ipsilateral side up. However, some studies have reported the usefulness of gravity-assisted brain retraction surgery, in which patients are placed laterally with the ipsilateral side down or up, enabling surgeons to approach the lesions through the ipsilateral side or through a contralateral interhemispheric fissure, respectively. This surgery requires less brain retraction. However, when using an operative microscope, performing this surgery requires the surgeon to operate in an awkward position. A recently developed high-definition (4K-HD) 3-D exoscope system, ORBEYE, can improve the surgeon’s posture while performing gravity-assisted brain retraction surgery. Methods: We report five cases with midline brain tumors managed by resectioning with gravity-assisted brain retraction surgery using ORBEYE. We also performed an ergonomic analysis of gravity-assisted brain retraction surgery with a craniotomy model and a neuronavigation system. Results: Gravity-assisted brain retraction surgery to the midline brain tumors was successfully performed for all five patients, using ORBEYE, without any postoperative neurological deficit. Conclusion: Gravity-assisted brain retraction surgery to the midline brain lesions using ORBEYE is feasible, and ORBEYE is ergonomically more favorable than a microscope. ORBEYE has the potential to generalize neurosurgical approaches considered difficult due to the surgeon’s awkward position, such as gravity-assisted brain retraction surgery.

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Robot-Assisted Stereoelectroencephalography: 2-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opab207 ◽

2021 ◽

Author(s):

Efstathios Kondylis ◽

Alexander C Whiting ◽

Stephen P Harasimchuk ◽

Juan Bulacio ◽

William Bingaman

Keyword(s):

Video Recording ◽

The United States ◽

Electrode Placement ◽

Robotic Assistance ◽

Seizure Onset ◽

Planning Software ◽

Seizure Onset Zone ◽

Barriers To Implementation ◽

New Applications ◽

Patients With Epilepsy

Abstract Invasive neuromonitoring is an important component of presurgical workup and seizure onset zone localization in patients with epilepsy being considered for surgical resection. In the United States, intraparenchymal stereoelectroencephalography (SEEG) electrodes have been replacing subdural grid electrodes for most cases, following a trend that has already matured in Europe. The use of robotic assistance has been shown to improve operative times and accuracy in SEEG electrode placement, as users benefit from the embedded planning software as well as the efficiency and accuracy of the robotic arm. The greatest barriers to implementation of this technology are the upfront cost and learning curve. This case-based surgeon's perspective operative video could benefit those considering incorporating robotic assistance for SEEG electrode placement. Those considering robotic assistance for pedicle screw placement and other budding applications may also benefit, as well as innovators looking for new applications. The patient consented for the procedure, video recording, and inclusion in subsequent publications.

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The Impact of Minimizing Brain Retraction in Aneurysm Surgery: Evaluation Using Magnetic Resonance Imaging

Neurosurgery ◽

10.1227/neu.0b013e31821819a0 ◽

2011 ◽

Vol 69 (2) ◽

pp. 344-348 ◽

Cited By ~ 15

Author(s):

Niklaus Krayenbühl ◽

Minna Oinas ◽

Eren Erdem ◽

Ali F. Krisht

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Mr Imaging ◽

Skull Base ◽

Neurological Deficits ◽

Cortical Surface ◽

Resonance Imaging ◽

Brain Retraction ◽

The Impact ◽

Surface Changes

Abstract BACKGROUND: Recent advances in skull base and microsurgical techniques minimize the need for brain retraction. OBJECTIVE: We studied the impact of such techniques in 36 patients (51 aneurysms) using magnetic resonance imaging (MRI). METHODS: Preoperative and 24 hours postoperative MR imaging was performed in patients undergoing microsurgical clipping of intracranial aneurysms. Images were evaluated for parenchymal signal changes. During surgery, use and time of brain retraction were recorded. The degree of cortical injury was quantified using a 0 to 3 scale (grade 0 = normal surface; 1 = pial/arachnoidal damage; 2 = gray matter injury; 3 = contusion/necrosis). RESULTS: Brain retraction by use of a brain spatula was used in all patients. Retraction times ranged from 14 to 290 minutes (mean, 84.1). Cortical surface changes were grade 0 in 86% and grade 1 in 14%; none showed grade 2 or 3 changes. In the postoperative MRI, 4 patients presented with parenchymal alterations, 4 with edema (11.1%), and 1 patient had additional contusion (2.8%). All lesions were confined to the temporal pole. The grade of cortical surface changes was not related to lesions found on MR imaging. No patients showed retraction-related neurological deficits. CONCLUSION: The incidence of evident mechanical parenchymal injury (infarction or contusion) is very low when appropriate microsurgical and skull base techniques are used. Minor pia-arachnoid injury should nevertheless continue to be attended through future advances.

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Minimally Invasive Bilateral Anterior Cingulotomy via Open Minicraniotomy Using a Novel Multiport Cisternoscope: A Cadaveric Demonstration

Operative Neurosurgery ◽

10.1093/ons/opy083 ◽

2018 ◽

Vol 16 (2) ◽

pp. 217-225

Author(s):

Sunil Manjila ◽

Benoit Rosa ◽

Margherita Mencattelli ◽

Pierre E Dupont

Keyword(s):

Minimally Invasive ◽

Electrode Placement ◽

Target Area ◽

Resonance Imaging ◽

Obsessive Compulsive ◽

Compulsive Disorder ◽

Navigational Cues ◽

Interhemispheric Fissure ◽

Cadaver Testing ◽

Magnetic Resonance Imaging Mri

Abstract BACKGROUND Bilateral anterior cingulotomy has been used to treat chronic pain, obsessive compulsive disorder, and addictions. Lesioning of the target area is typically performed using bilateral stereotactic electrode placement and target ablation, which involves transparenchymal access through both hemispheres. OBJECTIVE To evaluate an endoscopic direct-vision lesioning using a unilateral parasagittal minicraniotomy for minimally invasive bilateral anterior cingulotomy using a novel multiport endoscope through the anterior interhemispheric fissure. METHODS A novel multiport magnetic resonance imaging (MRI)-compatible neuroendoscope prototype is used to demonstrate cadaveric cingulate lesioning through a lateral imaging port while simultaneously viewing the pericallosal arteries as landmarks through a tip imaging port. The lateral port enables extended lesioning of the gyrus while rotation of the endoscope about its axis provides access to homologous areas of both hemispheres. RESULTS Cadaver testing confirmed the capability to navigate the multiport neuroendoscope between the hemispheres using concurrent imaging from the tip and lateral ports. The lateral port enabled exploration of the gyrus, visualization of lesioning, and subsequent inspection of lesions. Tip-port imaging provided navigational cues and allowed the operator to ensure that the endoscope tip did not contact tissue. The multiport design required instrument rotation in the coronal plane of only 20° to lesion both gyri, while a standard endoscope necessitated a rotation of 54°. CONCLUSION Multiport MRI-compatible endoscopy can be effectively used in cisternal endoscopy, whereby a unilateral parasagittal minicraniotomy can be used for endoscopic interhemispheric bilateral anterior cingulotomy.

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Electrical Stimulation Mapping of Brain Function: A Comparison of Subdural Electrodes and Stereo-EEG

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2020.611291 ◽

2020 ◽

Vol 14 ◽

Author(s):

Krista M. Grande ◽

Sarah K. Z. Ihnen ◽

Ravindra Arya

Keyword(s):

Electrical Stimulation ◽

Clinical Decision Making ◽

Cerebral Hemispheres ◽

Cortical Surface ◽

Functional Neuroanatomy ◽

Functional Responses ◽

Seizure Onset ◽

Subdural Electrodes ◽

Depth Electrodes ◽

Seizure Onset Zone

Despite technological and interpretative advances, the non-invasive modalities used for pre-surgical evaluation of patients with drug-resistant epilepsy (DRE), fail to generate a concordant anatomo-electroclinical hypothesis for the location of the seizure onset zone in many patients. This requires chronic monitoring with intracranial electroencephalography (EEG), which facilitates better localization of the seizure onset zone, and allows evaluation of the functional significance of cortical regions-of-interest by electrical stimulation mapping (ESM). There are two principal modalities for intracranial EEG, namely subdural electrodes and stereotactic depth electrodes (stereo-EEG). Although ESM is considered the gold standard for functional mapping with subdural electrodes, there have been concerns about its utility with stereo-EEG. This is mainly because subdural electrodes allow contiguous sampling of the dorsolateral convexity of cerebral hemispheres, and permit delineation of the extent of eloquent functional areas on the cortical surface. Stereo-EEG, while having relatively sparse sampling on the cortical surface, offers the ability to access the depth of sulci, mesial and basal surfaces of cerebral hemispheres, and deep structures such as the insula, which are largely inaccessible to subdural electrodes. As stereo-EEG is increasingly the preferred modality for intracranial monitoring, we find it opportune to summarize the literature for ESM with stereo-EEG in this narrative review. Emerging evidence shows that ESM for defining functional neuroanatomy is feasible with stereo-EEG, but probably requires a different approach for interpretation and clinical decision making compared to ESM with subdural electrodes. We have also compared ESM with stereo-EEG and subdural electrodes, for current thresholds required to evoke desired functional responses vs. unwanted after-discharges. In this regard, there is preliminary evidence that ESM with stereo-EEG may be safer than ESM with subdural grids. Finally, we have highlighted important unanswered clinical and scientific questions for ESM with stereo-EEG in the hope to encourage future research and collaborative efforts.

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Reorganization of Large-Scale Functional Networks During Low-Frequency Electrical Stimulation of the Cortical Surface

International Journal of Neural Systems ◽

10.1142/s0129065719500229 ◽

2019 ◽

Vol 30 (03) ◽

pp. 1950022

Author(s):

Bálint File ◽

Tibor Nánási ◽

Emília Tóth ◽

Virág Bokodi ◽

Brigitta Tóth ◽

...

Keyword(s):

Electrical Stimulation ◽

Large Scale ◽

Low Frequency ◽

Brain Regions ◽

Abnormal Behavior ◽

Cortical Surface ◽

Seizure Onset Zone ◽

Functional Topology ◽

Excitation Mechanisms

We investigated the functional network reorganization caused by low-frequency electrical stimulation (LFES) of human brain cortical surface. Intracranial EEG data from subdural grid positions were analyzed in 16 pre-surgery epileptic patients. LFES was performed by injecting current pulses (10[Formula: see text]mA, 0.2[Formula: see text]ms pulse width, 0.5[Formula: see text]Hz, 25 trials) into all adjacent electrode contacts. Dynamic functional connectivity analysis was carried out on two frequency bands (low: 1–4[Formula: see text]Hz; high: 10–40[Formula: see text]Hz) to investigate the early, high frequency and late, low frequency responses elicited by the stimulation. The centralization increased in early compared to late responses, suggesting a more prominent role of direct neural links between primarily activated areas and distant brain regions. Injecting the current into the seizure onset zone (SOZ) evoked a more integrated functional topology during the early (N1) period of the response, whereas during the late (N2) period — regardless of the stimulation site — the connectedness of the SOZ was elevated compared to the non-SOZ tissue. The abnormal behavior of the epileptic sub-network during both part of the responses supports the idea of the pathogenic role of impaired inhibition and excitation mechanisms in epilepsy.

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Localization of musicogenic epilepsy to Heschl’s gyrus and superior temporal plane: case report

Journal of Neurosurgery ◽

10.3171/2017.3.jns162559 ◽

2018 ◽

Vol 129 (1) ◽

pp. 157-164 ◽

Cited By ~ 9

Author(s):

Yasunori Nagahama ◽

Christopher K. Kovach ◽

Michael Ciliberto ◽

Charuta Joshi ◽

Ariane E. Rhone ◽

...

Keyword(s):

Temporal Lobe ◽

Electrode Placement ◽

Seizure Focus ◽

Depth Electrodes ◽

Heschl’S Gyrus ◽

Depth Electrode ◽

Seizure Onset Zone ◽

Temporal Structures ◽

Heschl's Gyrus ◽

Musicogenic Epilepsy

Musicogenic epilepsy (ME) is an extremely rare form of the disorder that is provoked by listening to or playing music, and it has been localized to the temporal lobe. The number of reported cases of ME in which intracranial electroencephalography (iEEG) has been used for seizure focus localization is extremely small, especially with coverage of the superior temporal plane (STP) and specifically, Heschl’s gyrus (HG). The authors describe the case of a 17-year-old boy with a history of medically intractable ME who underwent iEEG monitoring that involved significant frontotemporal coverage as well as coverage of the STP with an HG depth electrode anteriorly and a planum temporale depth electrode posteriorly. Five seizures occurred during the monitoring period, and a seizure onset zone was localized to HG and the STP. The patient subsequently underwent right temporal neocortical resection, involving the STP and including HG, with preservation of the mesial temporal structures. The patient remains seizure free 1 year postoperatively. To the authors’ knowledge, this is the first reported case of ME in which the seizure focus has been localized to HG and the STP with iEEG monitoring. The authors review the literature on iEEG findings in ME, explain their approach to HG depth electrode placement, and discuss the utility of STP depth electrodes in temporal lobe epilepsy.

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Functional Vagotopy in the Cervical Vagus Nerve of the Domestic Pig: Implications for the Study of Vagus Nerve Stimulation

10.1101/856989 ◽

2019 ◽

Cited By ~ 5

Author(s):

Megan L. Settell ◽

Bruce E. Knudsen ◽

Aaron M. Dingle ◽

Andrea L. McConico ◽

Evan N. Nicolai ◽

...

Keyword(s):

Vagus Nerve ◽

Nerve Stimulation ◽

Vagus Nerve Stimulation ◽

Electrode Placement ◽

Large Animal ◽

Domestic Pig ◽

Large Animal Models ◽

Common Electrode ◽

Distinct Grouping ◽

Clinical Interest

AbstractGiven current clinical interest in vagus nerve stimulation, there are surprisingly few studies characterizing the anatomy of the vagus nerve in large animal models as it pertains to on-and off-target engagement of local fibers. We sought to address this gap by evaluating vagal anatomy in the domestic pig, whose vagus nerve organization and size approximates the human cervical vagus nerve. We provide data on key features across the cervical vagus nerve including diameter, number and diameter of fascicles, and distance of fascicles from the epineural surface where stimulating electrodes are placed. We also characterized the relative locations of the superior and recurrent laryngeal branches of the vagus nerve that have been implicated in therapy limiting side effects with common electrode placement. We identified key variants across the cohort that may be important for vagus nerve stimulation with respect to changing sympathetic/parasympathetic tone, such as cross-connections to the sympathetic trunk. We discovered that cell bodies of pseudo-unipolar cells aggregate together to form a very distinct grouping within the nodose ganglion. This distinct grouping gives rise to a larger number of smaller fascicles as one moves caudally down the cervical vagus nerve. This often leads to a distinct bimodal organization, or ‘vagotopy’ that may be advantageous to exploit in design of electrodes/stimulation paradigms. Finally, we placed our data in context of historic and recent histology spanning mouse, rat, canine, pig, non-human primate and human models, thus providing a comprehensive resource to understand similarities and differences across species.

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