A new instrument for improved accuracy of stereotactic depth electrode placement

1996 ◽  
Vol 85 (2) ◽  
pp. 357-358 ◽  
Author(s):  
Richard D. Ashpole ◽  
Gavin C. A. Fabinyi ◽  
Milos Vosmansky
Keyword(s):  
Simple Device ◽  
Electrode Placement ◽  
Content Type ◽  
Depth Electrodes ◽  
Depth Electrode ◽  
New Instrument ◽  
Improved Accuracy ◽  
Fine Print

✓ A disadvantage of stereotactic placement of flexible depth electrodes is the risk of inaccurate positioning as a result of electrode movement when the introducer is withdrawn. A simple device that virtually eliminates this error is described.

Frameless stereotactic placement of depth electrodes in epilepsy surgery

2005 ◽  
Vol 102 (6) ◽  
pp. 1040-1045 ◽  
Author(s):  
Ashesh D. Mehta ◽  
Douglas Labar ◽  
Andrew Dean ◽  
Cynthia Harden ◽  
Syed Hosain ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Accurate Method ◽  
Electrode Placement ◽  
Entry Site ◽  
Content Type ◽  
Depth Electrodes ◽  
Custom Made ◽  
Stereotactic Navigation ◽  
The Mean ◽  
Fine Print

Object. Depth electrodes are useful in the identification of deep epileptogenic foci. Computerized tomography—magnetic resonance (CT/MR)— and angiography-guided frame-based techniques are safe and accurate but require four-point skull fixation that limits cranial access for the placement of additional grids and strips. The authors investigated the viability and accuracy of placing depth electrodes by using a commercially available frameless system. Methods. A slotted, custom-designed adapter was built to interface with the StealthStation Guide Frame-DT and 960-525 StealthFighter. The Cranial Navigation software was used to plan the trajectory and entry site based on preoperative spoiled gradient MR imaging studies. Forty-one depth electrodes were placed in 51 targets in 20 patients. Thirty-one of these electrodes were inserted through the temporal neocortex following craniotomy and placement of subdural grids, whereas 10 were placed through burr holes. All electrodes had contact either within (71%) or touching (29%) the target, 50 of which (98%) provided adequate recordings. Although the mean distance of the distal electrode contact from the intended target was 3.1 ± 0.5 mm, the mean distance to the edge of the anatomical structure was 0.4 ± 0.9 mm. Placement via the laterotemporal approach was significantly (p < 0.001) more accurate than that via the occipitotemporal approach. No complication occurred. Conclusions. Depth electrodes can be placed safely and accurately by using a commercially available frameless stereotactic navigation system and a custom-made adapter. Depth electrode placement to record ictal onsets during epilepsy surgery only requires the contacts to touch rather than to reside within the intended structure. The laterotemporal approach is a more accurate method of placing electrodes than is the occipitotemporal one, likely due to the increased distance from the entry point to the target.

A burr hole button to secure the electrode cable in depth electrode placement

1997 ◽  
Vol 86 (5) ◽  
pp. 905-906 ◽  
Author(s):  
Toshifumi Kamiryo ◽  
Edward R. Laws
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Burr Hole ◽  
Electrode Placement ◽  
Resonance Imaging ◽  
Content Type ◽  
Depth Electrode ◽  
Fine Print

✓ A simple magnetic resonance imaging—compatible buttonlike device was devised to fix a depth electrode cable securely in the burr hole used for its insertion during surgery for depth electrode placement. The button is tightly fixed in the burr hole and it holds the cable without allowing protrusion or tension on the wound.

scholarly journals Medically resistant pediatric insular-opercular/perisylvian epilepsy. Part 1: invasive monitoring using the parasagittal transinsular apex depth electrode

2016 ◽  
Vol 18 (5) ◽  
pp. 511-522 ◽  
Author(s):  
Alexander G. Weil ◽  
Aria Fallah ◽  
Evan C. Lewis ◽  
Sanjiv Bhatia
Keyword(s):  
Epilepsy Surgery ◽  
Electrode Placement ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Depth Electrodes ◽  
Depth Electrode ◽  
Age At Surgery ◽  
Feasible Alternative ◽  
The Mean ◽  
Drug Resistant Epilepsy

OBJECTIVE Insular lobe epilepsy (ILE) is an under-recognized cause of extratemporal epilepsy and explains some epilepsy surgery failures in children with drug-resistant epilepsy. The diagnosis of ILE usually requires invasive investigation with insular sampling; however, the location of the insula below the opercula and the dense middle cerebral artery vasculature renders its sampling challenging. Several techniques have been described, ranging from open direct placement of orthogonal subpial depth and strip electrodes through a craniotomy to frame-based stereotactic placement of orthogonal or oblique electrodes using stereo-electroencephalography principles. The authors describe an alternative method for sampling the insula, which involves placing insular depth electrodes along the long axis of the insula through the insular apex following dissection of the sylvian fissure in conjunction with subdural electrodes over the lateral hemispheric/opercular region. The authors report the feasibility, advantages, disadvantages, and role of this approach in investigating pediatric insular-opercular refractory epilepsy. METHODS The authors performed a retrospective analysis of all children (< 18 years old) who underwent invasive intracranial studies involving the insula between 2002 and 2015. RESULTS Eleven patients were included in the study (5 boys). The mean age at surgery was 7.6 years (range 0.5–16 years). All patients had drug-resistant epilepsy as defined by the International League Against Epilepsy and underwent comprehensive noninvasive epilepsy surgery workup. Intracranial monitoring was performed in all patients using 1 parasagittal insular electrode (1 patient had 2 electrodes) in addition to subdural grids and strips tailored to the suspected epileptogenic zone. In 10 patients, extraoperative monitoring was used; in 1 patient, intraoperative electrocorticography was used alone without extraoperative monitoring. The mean number of insular contacts was 6.8 (range 4–8), and the mean number of fronto-parieto-temporal hemispheric contacts was 61.7 (range 40–92). There were no complications related to placement of these depth electrodes. All 11 patients underwent subsequent resective surgery involving the insula. CONCLUSIONS Parasagittal transinsular apex depth electrode placement is a feasible alternative to orthogonally placed open or oblique-placed stereotactic methodologies. This method is safe and best suited for suspected unilateral cases with a possible extensive insular-opercular epileptogenic zone.

Robotic Navigated Laser Craniotomy for Depth Electrode Implantation in Epilepsy Surgery: A Cadaver Lab Study

2020 ◽  
Author(s):  
Karl Roessler ◽  
Fabian Winter ◽  
Tobias Wilken ◽  
Ekaterina Pataraia ◽  
Magdalena Mueller-Gerbl ◽  
...  
Keyword(s):  
Laser Beam ◽  
Epilepsy Surgery ◽  
Entry Point ◽  
Occipital Bone ◽  
Electrode Placement ◽  
Target Point ◽  
Twist Drill ◽  
Electrode Implantation ◽  
Depth Electrodes ◽  
Depth Electrode

Abstract Objective Depth electrode implantation for invasive monitoring in epilepsy surgery has become a standard procedure. We describe a new frameless stereotactic intervention using robot-guided laser beam for making precise bone channels for depth electrode placement. Methods A laboratory investigation on a head cadaver specimen was performed using a CT scan planning of depth electrodes in various positions. Precise bone channels were made by a navigated robot-driven laser beam (erbium:yttrium aluminum garnet [Er:YAG], 2.94-μm wavelength,) instead of twist drill holes. Entry point and target point precision was calculated using postimplantation CT scans and comparison to the preoperative trajectory plan. Results Frontal, parietal, and occipital bone channels for bolt implantation were made. The occipital bone channel had an angulation of more than 60 degrees to the surface. Bolts and depth electrodes were implanted solely guided by the trajectory given by the precise bone channels. The mean depth electrode length was 45.5 mm. Entry point deviation was 0.73 mm (±0.66 mm SD) and target point deviation was 2.0 mm (±0.64 mm SD). Bone channel laser time was ∼30 seconds per channel. Altogether, the implantation time was ∼10 to 15 minutes per electrode. Conclusion Navigated robot-assisted laser for making precise bone channels for depth electrode implantation in epilepsy surgery is a promising new, exact and straightforward implantation technique and may have many advantages over twist drill hole implantation.

Surgical management of epilepsy using epidural recordings to localize the seizure focus

1984 ◽  
Vol 60 (3) ◽  
pp. 457-466 ◽  
Author(s):  
Sidney Goldring ◽  
Erik M. Gregorie
Keyword(s):  
Temporal Lobe ◽  
Focal Epilepsy ◽  
Temporal Lobectomy ◽  
Epileptogenic Focus ◽  
Electrode Arrays ◽  
Content Type ◽  
Seizure Focus ◽  
Depth Electrodes ◽  
Sensory Evoked ◽  
Fine Print

✓ One hundred patients with focal epilepsy (44 were children) were evaluated with extraoperative electrocorticography via epidural electrode arrays. Localization of the epileptogenic focus was derived predominantly from recordings made during spontaneously occurring seizures. All resection procedures were carried out under general anesthesia. During anesthesia, the recording of sensory evoked responses made it possible to readily identify the sensorimotor region. Of the 100 patients, 72 underwent resection of an epileptogenic focus, and 33 of these were children. Those who did not have a resection either exhibited a diffuse seizure focus, failed to show an electrical seizure discharge in association with the clinical seizure, failed to have a seizure during the period of monitoring, or failed to exhibit conclusive changes for identifying a focus in the interictal record. Fifty-seven patients (29 children and 28 adults) who had a resection have been followed for between 1 and 12 years. Eighteen (62%) of the 29 children and 18 (64%) of the 28 adults enjoyed a good result. Twenty of the 100 patients reported here had temporal lobe epilepsy. They were candidates for recordings with depth electrodes to identify their focus, but they were evaluated instead with epidural recordings; the method is described. In 15 of them, a unilateral focus was identified and they underwent an anterior temporal lobectomy. Pathological changes were found in every case and, in 11 patients, the epidural recordings distinguished between a medial and a lateral focus. Ten of these patients have been followed for 9 months to 3½ years, and seven have had a good result. The observations suggest that epidural electrodes may be used in lieu of depth electrodes for identifying the symptomatic temporal lobe.

A precise technique for craniotomy localization using computerized tomography

1981 ◽  
Vol 54 (3) ◽  
pp. 416-418 ◽  
Author(s):  
Vincent C. Hinck ◽  
Guy L. Clifton
Keyword(s):  
Computerized Tomography ◽  
Preoperative Localization ◽  
Simple Device ◽  
Content Type ◽  
Fine Print

✓ The authors describe a simple device which, when used with computerized tomography, provides precise preoperative localization of craniotomy.

A new bipolar right-angled coagulation forceps for pituitary surgery

1983 ◽  
Vol 58 (4) ◽  
pp. 614-615 ◽  
Author(s):  
Alex M. Landolt
Keyword(s):  
Pituitary Surgery ◽  
Bipolar Coagulation ◽  
Content Type ◽  
Anterior Aspect ◽  
New Instrument ◽  
Transsphenoidal Pituitary Surgery ◽  
Fine Print

✓ A new instrument is described which allows easy and precise bipolar coagulation of the anterior intercavernous sinus. In some cases this sinus covers the anterior aspect of the pituitary and may render transsphenoidal pituitary surgery difficult.

Surgical therapy for medically intractable epilepsy

1987 ◽  
Vol 66 (4) ◽  
pp. 489-499 ◽  
Author(s):  
George A. Ojemann
Keyword(s):  
Temporal Lobe ◽  
Surgical Therapy ◽  
Imaging Techniques ◽  
Intractable Epilepsy ◽  
Content Type ◽  
Human Epilepsy ◽  
Depth Electrodes ◽  
Positron Emission ◽  
Intraoperative Management ◽  
Fine Print

✓ There has been a recent renewal of interest in surgical therapy for medically intractable epilepsies. Cortical resection and callosotomy are the most widely accepted modes of surgical management. The indications for each of these approaches are reviewed. Although there has been much interest in imaging techniques, including positron emission tomography, to identify epileptogenic zones, identification still depends primarily on the electroencephalogram (EEG). There are several approaches to the evaluation and intraoperative management of patients undergoing cortical resection for temporal lobe epileptogenic zones. These range from selection based on scalp interictal EEG criteria, with resections guided by electrocorticography and functional mapping, to selection based on the location of ictal onset as recorded by chronically implanted depth electrodes, with an anatomically standard resection of the temporal lobe or resection limited to amygdalohippocampectomy. No one approach provides the optimum balance of benefits to risks and costs for all patients. The relative value of the different approaches for various populations of patients with medically intractable partial complex seizures is reviewed. Techniques for minimizing the morbidity of these operations, especially in regard to language and memory, are also discussed, as are the contributions to an understanding of the neurobiology of human epilepsy and human higher functions derived from the surgical therapy of epilepsy.

A new neurosurgical irrigating sucking cutter

1986 ◽  
Vol 65 (1) ◽  
pp. 120-121
Author(s):  
Kevin F. Bleasel ◽  
Richard B. Frost
Keyword(s):  
Clinical Practice ◽  
Content Type ◽  
New Instrument ◽  
Fine Print

✓ A new instrument has been developed for the removal of tumors located in areas difficult to reach. It operates by suctioning and cutting tissue, and is equipped with an irrigating sucker. This device is described and its successful use in clinical practice is summarized.

scholarly journals Local distribution and toxicity of prolonged hippocampal infusion of muscimol

2005 ◽  
Vol 103 (6) ◽  
pp. 1035-1045 ◽  
Author(s):  
John D. Heiss ◽  
Stuart Walbridge ◽  
Paul Morrison ◽  
Robert R. Hampton ◽  
Susumu Sato ◽  
...  
Keyword(s):  
Intractable Epilepsy ◽  
Fluid Distribution ◽  
Electrode Placement ◽  
Distribution Data ◽  
Mesial Temporal Sclerosis ◽  
Partial Seizures ◽  
Mr Images ◽  
Complex Partial Seizures ◽  
Content Type ◽  
Fine Print

Object. The activity of γ-aminobutyric acid (GABA), the principal inhibitory neurotransmitter, is reduced in the hippocampus in patients with complex partial seizures from mesial temporal sclerosis. To provide preliminary safety and distribution data on using convection-enhanced delivery of agents to treat complex partial seizures and to test the efficacy and safety of regional selective neuronal suppression, the authors infused muscimol, a GABA-A receptor agonist, directly into the hippocampus of nonhuman primates using an integrated catheter electrode. Methods. Ten rhesus monkeys were divided into three groups: 1) use of catheter electrode alone (four monkeys); 2) infusion of escalating concentrations of muscimol followed by vehicle (three monkeys); and 3) infusion of vehicle and subsequent muscimol mixed with muscimol tracer (three monkeys). Infusions were begun 5 days after catheter electrode placement and continued for 5.6 days before switching to the other agent. Head magnetic resonance (MR) images and electroencephalography recordings were obtained before and during the infusions. Brain histological studies and quantitative autoradiography were performed. Neurological function was normal in controls and when muscimol concentrations were 0.125 mM or less, whereas higher concentrations (0.5 and 1 mM) produced reversible apathy and somnolence. Fluid distribution was demonstrated on MR images and muscimol distribution was demonstrated on autoradiographs throughout the hippocampus and adjacent white matter. Conclusions. Targeted modulation of neuronal activity is a reasonable research strategy for the investigation and treatment of medically intractable epilepsy.

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