Accuracy of frameless image-guided implantation of depth electrodes for intracranial epilepsy monitoring

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OBJECTIVE

Various techniques are available for stereotactic implantation of depth electrodes for intracranial epilepsy monitoring. The goal of this study was to evaluate the accuracy and effectiveness of frameless MRI-guided depth electrode implantation.

METHODS

Using a frameless MRI-guided stereotactic approach (Stealth), depth electrodes were implanted in patients via burr holes or craniotomy, mostly into the medial temporal lobe. In all cases in which it was possible, postoperative MR images were coregistered to planning MR images containing the marked targets for quantitative analysis of intended versus actual location of each electrode tip. In the subset of MR images done with sufficient resolution, qualitative assessment of anatomical accuracy was performed. Finally, the effectiveness of implanted electrodes for identifying seizure onset was retrospectively examined.

RESULTS

Sixty-eight patients underwent frameless implantation of 413 depth electrodes (96% to mesial temporal structures) via burr holes by one surgeon at 2 institutions. In 36 patients (203 electrodes) planning and postoperative MR images were available for quantitative analysis; an additional 8 procedures with 19 electrodes implanted via craniotomy for grid were also available for quantitative analysis. The median distance between intended target and actual tip location was 5.19 mm (mean 6.19 ± 4.13 mm, range < 2 mm–29.4 mm). Inaccuracy for transtemporal depths was greater along the electrode (i.e., deep), and posterior, whereas electrodes inserted via an occipital entry deviated radially. Failure to localize seizure onset did not result from implantation inaccuracy, although 2 of 62 patients (3.2%)—both with electrodes inserted occipitally—required reoperation. Complications were mostly transient, but resulted in long-term deficit in 2 of 68 patients (3%).

CONCLUSIONS

Despite modest accuracy, frameless depth electrode implantation was sufficient for seizure localization in the medial temporal lobe when using the orthogonal approach, but may not be adequate for occipital trajectories.

ABBREVIATIONS AH = anterior hippocampus; MH = midhippocampus; PH = posterior hippocampus.

Article Information

Correspondence Robert E. Gross: Emory University School of Medicine, Atlanta, GA. rgross@emory.edu.

INCLUDE WHEN CITING Published online March 22, 2019; DOI: 10.3171/2018.12.JNS18749.

Disclosures Dr. Gross is a consultant for Medtronic, Inc., on work unrelated to this research. Dr. Mayo is a consultant for the American Institute of Biological Sciences.

© AANS, except where prohibited by US copyright law.

Headings

Figures

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    Flowchart of patients included in the study. * One patient had a temporal burr hole for depth electrodes contralateral to craniotomy for grid and depth electrodes. EU = Emory University; proc = procedures; UU = University of Utah.

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    Photographs showing frameless implantation of depth electrodes via transtemporal (orthogonal) approach. A: The setup is depicted, showing the reference frame on the left attached to the operating room table by one Vertek arm, and on the right the Guideframe DT is held within the Precision stereoguide, attached to the second Vertek arm. B: A closer view showing the depth electrode inserted through the slotted cannula within the Guideframe DT. The depth electrode is inserted through a temporal burr hole. C: The burr hole has 4 tie-down holes drilled in it. Monocryl sutures (arrowhead) have been passed through the tie-down holes to anchor the electrodes for the duration of the invasive monitoring session. To allow the anchoring suture to be broken to release the depth electrode for bedside removal, a heavy nylon suture (e.g., 1-0) is tied within the monocryl (arrow points to the tail of the nylon suture). The tails of the nylon are subsequently passed through the same hole in the skin as the depth electrode by using a passing needle. By pulling on the nylon tails the monocryl is broken, allowing the depth electrode to be pulled through the skin. D: The final arrangement of 4 depth electrodes tied down within the burr hole. Modified from Gross RE, Rowland NC, Sung EK, LaBorde DV, Suleiman SL. (2012). Anchoring Depth Electrodes for Bedside Removal: A “Break-Away” Suturing Technique for Intracranial Monitoring. Neurosurgery, 71, ons52–ons57, by permission of Oxford University Press. http://doi.org/10.1227/NEU.0b013e31825569c0. Figure is available in color online only.

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    Analysis of depth electrode insertion accuracy. A: Screenshot of StealthStation software used for depth electrode placement analysis showing the planned orthogonal electrode trajectories to the amygdala, AH (pes), MH, and PH. The images are aligned on the anterior hippocampal (pes) trajectory (arrowheads). B: For implantation the Guideframe is aligned with the planned trajectory using “trajectory views” (arrowheads) and “guidance view” (lower right frame within panel B). The “distance to target” from the bottom of the Guideframe is indicated by the software (here, 53.7 mm). C: Postoperative scan showing the electrode susceptibility artifacts, aligned to the anterior hippocampal electrode (arrowheads) and coregistered to the preoperative planning Stealth MR image. (The larger artifacts visible are from strip electrode contacts.) D: To measure the implantation error directly, a trajectory (arrowheads) was made from the planned electrode target to a point 5 mm (see text) proximal to the end of the electrode artifact. The distance-to-target measurement then indicates this error (here, 4.0 mm for the posterior hippocampal depth electrode).

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    Distribution of depth electrode insertion accuracy measurements. A: Histogram of the average calculated distances between the actual and intended locations of each depth electrode, by insertion approach (occipital, temporal [orthogonal], and parietal). B: Graph of the average calculated distances between the actual and intended locations of the depth electrodes for each patient, along with the minimum and maximum distances. Where the line comes to the upper edge of the graph, the actual maximal measurement is not shown (> 15 mm). Numbers on the x axes designate patient numbers 1–32, etc. C: Scatterplot of the distribution of depth electrodes relative to their intended locations. The figure demonstrates a statistically significant bias in the medial (p < 0.01) and posterior (p < 0.001) directions.

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    Flowchart showing outcomes of intracranial depth electrodes implanted via burr holes. The outcome of invasive monitoring for all patients is shown for bilateral (A) and unilateral (B) depth electrode insertion. ATL = anterior temporal lobectomy; GTC = generalized tonic-clonic seizure; RNS = responsive neurostimulation; SAH = selective amygdalohippocampectomy; SANTE = stimulation of the anterior nucleus of the thalamus for epilepsy; VNS = vagus nerve stimulator.

References

  • 1

    Alp MSDujovny MMisra MCharbel FTAusman JI: Head registration techniques for image-guided surgery. Neurol Res 20:31371998

  • 2

    Ammirati MGross JDAmmirati GDugan S: Comparison of registration accuracy of skin- and bone-implanted fiducials for frameless stereotaxis of the brain: a prospective study. Skull Base 12:1251302002

  • 3

    Bancaud JAngelergues RBernouilli CBonis ABordas-Ferrer MBresson M: Functional stereotaxic exploration (SEEG) of epilepsy. Electroencephalogr Clin Neurophysiol 28:85861970

  • 4

    Blatt DRRoper SNFriedman WA: Invasive monitoring of limbic epilepsy using stereotactic depth and subdural strip electrodes: surgical technique. Surg Neurol 48:74791997

  • 5

    Bourgeois GMagnin MMorel ASartoretti SHuisman TTuncdogan E: Accuracy of MRI-guided stereotactic thalamic functional neurosurgery. Neuroradiology 41:6366451999

  • 6

    Cardinale FCossu MCastana LCasaceli GSchiariti MPMiserocchi A: Stereoelectroencephalography: surgical methodology, safety, and stereotactic application accuracy in 500 procedures. Neurosurgery 72:3533662013

  • 7

    Cossu MCardinale FCastana LCitterio AFrancione STassi L: Stereoelectroencephalography in the presurgical evaluation of focal epilepsy: a retrospective analysis of 215 procedures. Neurosurgery 57:7067182005

  • 8

    De Almeida ANOlivier AQuesney FDubeau FSavard GAndermann F: Efficacy of and morbidity associated with stereoelectroencephalography using computerized tomography—or magnetic resonance imaging-guided electrode implantation. J Neurosurg 104:4834872006

  • 9

    Dean DKamath JDuerk JLGanz E: Validation of object-induced MR distortion correction for frameless stereotactic neurosurgery. IEEE Trans Med Imaging 17:8108161998

  • 10

    Eisenschenk SGilmore RLCibula JERoper SN: Lateralization of temporal lobe foci: depth versus subdural electrodes. Clin Neurophysiol 112:8368442001

  • 11

    Fried IWilson CLMaidment NTEngel J JrBehnke EFields TA: Cerebral microdialysis combined with single-neuron and electroencephalographic recording in neurosurgical patients. Technical note. J Neurosurg 91:6977051999

  • 12

    Gross RERowland NCSung EKLaBorde DVSuleiman SL: Anchoring depth electrodes for bedside removal: a “break-away” suturing technique for intracranial monitoring. Neurosurgery 71 (1 Suppl Operative):52572012

  • 13

    Henderson JM: Frameless localization for functional neurosurgical procedures: a preliminary accuracy study. Stereotact Funct Neurosurg 82:1351412004

  • 14

    Holloway KLGaede SEStarr PARosenow JMRamakrishnan VHenderson JM: Frameless stereotaxy using bone fiducial markers for deep brain stimulation. J Neurosurg 103:4044132005

  • 15

    Khan MFMewes KGross RESkrinjar O: Assessment of brain shift related to deep brain stimulation surgery. Stereotact Funct Neurosurg 86:44532008

  • 16

    Knaus HAbbushi AHoffmann KTSchwarz KHaberl HThomale UW: Measurements of burr-hole localization for endoscopic procedures in the third ventricle in children. Childs Nerv Syst 25:2932992009

  • 17

    Maciunas RJGalloway RL JrLatimer JW: The application accuracy of stereotactic frames. Neurosurgery 35:6826951994

  • 18

    Mascott CR: In vivo accuracy of image guidance performed using optical tracking and optimized registration. J Neurosurg 105:5615672006

  • 19

    Mehta ADLabar DDean AHarden CHosain SPak J: Frameless stereotactic placement of depth electrodes in epilepsy surgery. J Neurosurg 102:104010452005

  • 20

    Murphy MAO’Brien TJCook MJ: Insertion of depth electrodes with or without subdural grids using frameless stereotactic guidance systems—technique and outcome. Br J Neurosurg 16:1191252002

  • 21

    Ortler MSohm FEisner WBauer RDobesberger JTrinka E: Frame-based vs frameless placement of intrahippocampal depth electrodes in patients with refractory epilepsy: a comparative in vivo (application) study. Neurosurgery 68:8818872011

  • 22

    Song JKAbou-Khalil BKonrad PE: Intraventricular monitoring for temporal lobe epilepsy: report on technique and initial results in eight patients. J Neurol Neurosurg Psychiatry 74:5615652003

  • 23

    Van Roost DSolymosi LSchramm Jvan Oosterwyck BElger CE: Depth electrode implantation in the length axis of the hippocampus for the presurgical evaluation of medial temporal lobe epilepsy: a computed tomography-based stereotactic insertion technique and its accuracy. Neurosurgery 43:8198271998

  • 24

    Wray CDKraemer DLYang TPoliachik SLKo ALPoliakov A: Freehand placement of depth electrodes using electromagnetic frameless stereotactic guidance. J Neurosurg Pediatr 8:4644672011

  • 25

    Yeh HSTaha JMTobler WD: Implantation of intracerebral depth electrodes for monitoring seizures using the Pelorus stereotactic system guided by magnetic resonance imaging. Technical note. J Neurosurg 78:1381411993

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