Category: Epilepsy

Posted on

Selective amygdalohippocampectomy via a navigated temporobasal approach, when veins forbid elevation of the temporal lobe.jpg

Acta Neurochir (2018) 160:597–601

Selective amygdalohippocampectomy is an effective treatment option for mesial temporal lobe epilepsy associated with hippocampal sclerosis.

Methods To describe and emphasize potential pitfalls during selective amygdalohippocampectomy via a modified navigated temporobasal approach, in cases, where temporal basal veins hinder the required elevation of the temporal lobe.

Conclusions Selective amygdalohippocampectomy via navigated temporobasal approach is a safe procedure that can reduce the rate of visual field deficits by avoiding damage of optic radiation. The option of a small subpial corticotomy of the inferior temporal gyrus allows sufficient elevation of the temporal lobe in cases with difficult basal venous anatomy.

Keywords

Posted on

Surgery guided with intraoperative electrocorticography in patients with low-grade glioma and refractory seizures

J Neurosurg 128:840–845, 2018

Using intraoperative electrocorticography (ECoG) to identify epileptogenic areas and improve postoperative seizure control in patients with low-grade gliomas (LGGs) remains inconclusive. In this study the authors retrospectively report on a surgery strategy that is based on intraoperative ECoG monitoring.

METHODS A total of 108 patients with LGGs presenting at the onset of refractory seizures were included. Patients were divided into 2 groups. In Group I, all patients underwent gross-total resection (GTR) combined with resection of epilepsy areas guided by intraoperative ECoG, while patients in Group II underwent only GTR. Tumor location, tumor side, tumor size, seizure-onset features, seizure frequency, seizure duration, preoperative antiepileptic drug therapy, intraoperative electrophysiological monitoring, postoperative Engel class, and histological tumor type were compared between the 2 groups.

RESULTS Univariate analysis demonstrated that tumor location and intraoperative ECoG monitoring correlated with seizure control. There were 30 temporal lobe tumors, 22 frontal lobe tumors, and 2 parietal lobe tumors in Group I, with 18, 24, and 12 tumors in those same lobes, respectively, in Group II (p < 0.05). In Group I, 74.07% of patients were completely seizure free (Engel Class I), while 38.89% in Group II (p < 0.05). In Group I, 96.30% of the patients achieved satisfactory postoperative seizure control (Engel Class I or II), compared with 77.78% in Group II (p < 0.05). Intraoperative ECoG monitoring indicated that in patients with temporal lobe tumors, most of the epileptic discharges (86.7%) were detected at the anterior part of the temporal lobe. In these patients with epilepsy discharges located at the anterior part of the temporal lobe, satisfactory postoperative seizure control (93.3%) was achieved after resection of the tumor and the anterior part of the temporal lobe.

CONCLUSIONS Intraoperative ECoG monitoring provided the exact location of epileptogenic areas and significantly improved postoperative seizure control of LGGs. In patients with temporal lobe LGGs, resection of the anterior temporal lobe with epileptic discharges was sufficient to control seizures.

Posted on

Surgical Treatment of Mesiotemporal Lobe Epilepsy: Which Approach is Favorable?

Neurosurgery 81:992–1004, 2017

Mesiotemporal lobe epilepsy is one of the most frequent causes for pharmacoresistant epilepsy. Different surgical approaches to the mesiotemporal area are used.

OBJECTIVE: To analyze epileptological and neuropsychological results as well as complications of different surgical strategies.

METHODS: This retrospective study is based on a consecutive series of 458 patients all harboring pharmacoresistant mesiotemporal lobe epilepsy. Following procedures were performed: standard anterior temporal lobectomy, anterior temporal or key-hole resection, extended lesionectomy, and transsylvian and subtemporal selective amygdalohippocampectomy. Postoperative outcome was evaluated according to different surgical procedures.

RESULTS: Overall, 1 yr after surgery 315 of 432 patients (72.9%) were classified Engel I; in particular, 72.8% were seizure-free after anterior temporal lobectomy, 76.9% after key-hole resection, 84.4% after extended lesionectomy, 70.3% after transylvian selective amygdalohippocampectomy, and 59.1% after subtemporal selective amygdalohippocampectomy. No significant differences in seizure outcome were found between different resective procedures, neither in short-term nor long-term follow-up. There was no perioperative mortality. Permanent morbidity was encountered in 4.4%. There were no significant differences in complications between different resection types. In the majority of patients, selective attention improved following surgery. Patients after left-sided operations performed significantly worse regarding verbal memory as compared to right-sided procedures. However, surgical approach had no significant effect on memory outcome.

CONCLUSION: Different surgical approaches for mesiotemporal epilepsy analyzed resulted in similar epileptological, neuropsychological results, and complication rates. Therefore, the approach for the individual patient does not only depend on the specific localization of the epileptogenic area, but also on the experience of the surgeon.

Posted on

Long-term surgical results of supplementary motor area epilepsy surgery

J Neurosurg 127:1153–1159, 2017

Supplementary motor area (SMA) epilepsy is a well-known clinical condition; however, long-term surgical outcome reports are scarce and correspond to small series or isolated case reports. The aim of this study is to present the surgical results of SMA epilepsy patients treated at 2 reference centers in Mexico City.

METHODS For this retrospective descriptive study (1999–2014), 52 patients underwent lesionectomy and/or corticectomy of the SMA that was guided by electrocorticography (ECoG). The clinical, neurophysiological, neuroimaging, and pathological findings are described. The Engel scale was used to classify surgical outcome. Descriptive statistics, Student t-test, and Friedman, Kruskal-Wallis, and chi-square tests were used.

RESULTS Of these 52 patients, the mean age at epilepsy onset was 26.3 years, and the mean preoperative seizure frequency was 14 seizures per month. Etiologies included low-grade tumors in 28 (53.8%) patients, cortical dysplasia in 17 (32.7%) patients, and cavernomas in 7 (13.5%) patients. At a mean follow-up of 5.7 years (range 1–10 years), 32 patients (61%) were classified as Engel Class I, 16 patients (31%) were classified as Engel Class II, and 4 (8%) patients were classified as Engel Class III. Overall seizure reduction was significant (p = 0.001). The absence of early postsurgical seizures and lesional etiology were associated with the outcome of Engel Class I (p = 0.05). Twenty-six (50%) patients had complications in the immediate postoperative period, all of which resolved completely with no residual neurological deficits.

CONCLUSIONS Surgery for SMA epilepsy guided by ECoG using a multidisciplinary and multimodality approach is a safe, feasible procedure that shows good seizure control, moderate morbidity, and no mortality.

Posted on

Histopathological Findings in Brain Tissue Obtained during Epilepsy Surgery

N Engl J Med 2017;377:1648-56

Detailed neuropathological information on the structural brain lesions underlying seizures is valuable for understanding drug-resistant focal epilepsy.

METHODS We report the diagnoses made on the basis of resected brain specimens from 9523 patients who underwent epilepsy surgery for drug-resistant seizures in 36 centers from 12 European countries over 25 years. Histopathological diagnoses were determined through examination of the specimens in local hospitals (41%) or at the German Neuropathology Reference Center for Epilepsy Surgery (59%).

RESULTS The onset of seizures occurred before 18 years of age in 75.9% of patients overall, and 72.5% of the patients underwent surgery as adults. The mean duration of epilepsy before surgical resection was 20.1 years among adults and 5.3 years among children. The temporal lobe was involved in 71.9% of operations. There were 36 histopathological diagnoses in seven major disease categories. The most common categories were hippocampal sclerosis, found in 36.4% of the patients (88.7% of cases were in adults), tumors (mainly ganglioglioma) in 23.6%, and malformations of cortical development in 19.8% (focal cortical dysplasia was the most common type, 52.7% of cases of which were in children). No histopathological diagnosis could be established for 7.7% of the patients.

CONCLUSIONS In patients with drug-resistant focal epilepsy requiring surgery, hippocampal sclerosis was the most common histopathological diagnosis among adults, and focal cortical dysplasia was the most common diagnosis among children. Tumors were the second most common lesion in both groups. (Funded by the European Union and others.)

Posted on

Epilepsy Surgeries Requiring an Operculoinsular Cortectomy

Neurosurgery 81:602–612, 2017

Epilepsy surgeries requiring an operculoinsulectomy pose significant difficulties because the perisylvian area is highly vascular, deep, and functional.

OBJECTIVE: To report the operative technique and results of epilepsy surgeries requiring an operculoinsular cortectomy at our institution.

METHODS: The data of all consecutive patients who had undergone an epilepsy surgery requiring an operculoinsular cortectomy with a minimum follow-up of 1 yr were reviewed. Tumor and vascular malformation cases were excluded. Surgical techniques are described based on findings during surgery.

RESULTS: Twenty-five patients underwent an epilepsy surgery requiring an operculoinsular cortectomy: mean age at surgery was 35 y (9-51), mean duration of epilepsy was 19 y (5-36), 14were female, and mean duration of follow-up was 4.7 y (1-16).Magnetic resonance imaging of the operculoinsular area was normal or revealed questionable nonspecific findings in 72% of cases. Investigation with intracranial EEG electrodes was done in 17 patients. Surgery was performed on the dominant side for language in 7 patients. An opercular resectionwasperformed inallbut2patientswhoonlyhadan insulectomy.Engel class I seizure control was achieved in 80% of patients. Postoperative neurological deficits (paresis, dysphasia, alteration of taste, smell, hearing, pain, and thermal perceptions) were frequent (75%) but always transient except for 1 patient with persistent mild alteration of thermal and pain perception.

CONCLUSION: Surgical treatment of operculoinsular epilepsy is effective in achieving seizure control and is associated with an acceptable long-term complication rate.

Posted on

Protocol for motor and language mapping by navigated TMS in patients and healthy volunteers

Acta Neurochir (2017) 159:1187–1195

Navigated transcranial magnetic stimulation (nTMS) is increasingly used for preoperative mapping of motor function, and clinical evidence for its benefit for brain tumor patients is accumulating. In respect to language mapping with repetitive nTMS, literature reports have yielded variable results, and it is currently not routinely performed for presurgical language localization. The aim of this project is to define a common protocol for nTMS motor and language mapping to standardize its neurosurgical application and increase its clinical value.

Methods: The nTMS workshop group, consisting of highly experienced nTMS users with experience of more than 1500 preoperative nTMS examinations, met in Helsinki in January 2016 for thorough discussions of current evidence and personal experiences with the goal to recommend a standardized protocol for neurosurgical applications.

Results: nTMS motor mapping is a reliable and clinically validated tool to identify functional areas belonging to both normal and lesioned primary motor cortex. In contrast, this is less clear for language-eloquent cortical areas identified by nTMS. The user group agreed on a core protocol, which enables comparison of results between centers and has an excellent safety profile. Recommendations for nTMS motor and language mapping protocols and their optimal clinical integration are presented here.

Conclusion: At present, the expert panel recommends nTMS motor mapping in routine neurosurgical practice, as it has a sufficient level of evidence supporting its reliability. The panel recommends that nTMS language mapping be used in the framework of clinical studies to continue refinement of its protocol and increase reliability.

Posted on

Seizure outcomes of temporal lobe epilepsy surgery in patients with normal MRI and without specific histopathology

Acta Neurochir (2017) 159:757–766

Seizure outcome following surgery in pharmacoresistant temporal lobe epilepsy patients with normal magnetic resonance imaging and normal or non-specific histopathology is not sufficiently presented in the literature.

Methods In a retrospective design, we reviewed data of 263 patients who had undergone temporal lobe epilepsy surgery and identified 26 (9.9%) who met the inclusion criteria. Seizure outcomes were determined at 2-year follow-up. Potential predictors of Engel class I (satisfactory outcome) were identified by logistic regression analyses.

Results Engel class I outcome was achieved in 61.5% of patients, 50% being completely seizure free (Engel class IA outcome). The strongest predictors of satisfactory outcome were typical ictal seizure semiology (p = 0.048) and localised ictal discharges on scalp EEG (p = 0.036).

Conclusion Surgery might be an effective treatment choice for the majority of these patients, although outcomes are less favourable than in patients with magnetic resonance imaging defined lesional temporal lobe epilepsy. Typical ictal seizure semiology and localised ictal discharges on scalp EEG were predictors of Engel class I outcome.

Posted on

A novel miniature robotic device for frameless implantation of depth electrodes in refractory epilepsy

J Neurosurg 126:1622–1628, 2017

The authors’ group recently published a novel technique for a navigation-guided frameless stereotactic approach for the placement of depth electrodes in epilepsy patients. To improve the accuracy of the trajectory and enhance the procedural workflow, the authors implemented the iSys1 miniature robotic device in the present study into this routine.

METHODS As a first step, a preclinical phantom study was performed using a human skull model, and the accuracy and timing between 5 electrodes implanted with the manual technique and 5 with the aid of the robot were compared. After this phantom study showed an increased accuracy with robot-assisted electrode placement and confirmed the robot’s ability to maintain stability despite the rotational forces and the leverage effect from drilling and screwing, patients were enrolled and analyzed for robot-assisted depth electrode placement at the authors’ institution from January 2014 to December 2015. All procedures were performed with the S7 Surgical Navigation System with Synergy Cranial software and the iSys1 miniature robotic device.

RESULTS Ninety-three electrodes were implanted in 16 patients (median age 33 years, range 3–55 years; 9 females, 7 males). The authors saw a significant increase in accuracy compared with their manual technique, with a median deviation from the planned entry and target points of 1.3 mm (range 0.1–3.4 mm) and 1.5 mm (range 0.3–6.7 mm), respectively. For the last 5 patients (31 electrodes) of this series the authors modified their technique in placing a guide for implantation of depth electrodes (GIDE) on the bone and saw a significant further increase in the accuracy at the entry point to 1.18 ± 0.5 mm (mean ± SD) compared with 1.54 ± 0.8 mm for the first 11 patients (p = 0.021). The median length of the trajectories was 45.4 mm (range 19–102.6 mm). The mean duration of depth electrode placement from the start of trajectory alignment to fixation of the electrode was 15.7 minutes (range 8.5–26.6 minutes), which was significantly faster than with the manual technique. In 12 patients, depth electrode placement was combined with subdural electrode placement. The procedure was well tolerated in all patients. The authors did not encounter any case of hemorrhage or neurological deficit related to the electrode placement. In 1 patient with a psoriasis vulgaris, a superficial wound infection was encountered. Adequate physiological recordings were obtained from all electrodes. No additional electrodes had to be implanted because of misplacement.

CONCLUSIONS The iSys1 robotic device is a versatile and easy to use tool for frameless implantation of depth electrodes for the treatment of epilepsy. It increased the accuracy of the authors’ manual technique by 60% at the entry point and over 30% at the target. It further enhanced and expedited the authors’ procedural workflow.

Posted on

Mesial Extratemporal Lobe Epilepsy: Clinical Features and Surgical Strategies

Neurosurgery 80:269–278, 2017

Extratemporal lobe epilepsy surgery remains a diagnostic and therapeutic challenge. Scalp electroencephalography (EEG) correlates, clinical semiology, and imaging findings are often ambiguous or difficult to interpret, necessitating the need for invasive recordings. This is particularly true for those extratemporal lobe epilepsy cases in which seizures develop from the midline.

OBJECTIVE: The aim of this study was to examine the clinical features and surgical strategies in mesial extratemporal lobe epilepsy.

METHODS: A retrospective study reviewing clinical and surgical characteristics was conducted in 30 patients who underwent epilepsy surgery in mesial extratemporal areas at our institution between 1991 and 2011.

RESULTS: Although the location of the epileptogenic zone was associated with specific seizure types, semiology proved to be heterogeneous. Although scalp EEG was of good lateralizing value, it was poor for localizing the epileptogenic zone, necessitating a frequent need for invasive electroencephalographic recordings.

CONCLUSION: Surgical resections in mesial extratemporal regions were found to be safe and resulted in satisfactory seizure outcomes.

Posted on

Laser Interstitial Thermal Therapy for Mesial Temporal Lobe Epilepsy

Neurosurgery 79:S83–S91, 2016

Approximately one-third of patients with epilepsy do not achieve adequate seizure control through medical management alone. Mesial temporal lobe epilepsy (MTLE) is one of the most common forms of medically refractory epilepsy referred for surgical management. Stereotactic laser amygdalohippocampotomy using magnetic resonance–guided laser interstitial thermal therapy (MRg-LITT) is an important emerging therapy for MTLE.

Initial published reports support MRg-LITT as a less invasive surgical option with a shorter hospital stay and fewer neurocognitive side effects compared with craniotomy for anterior temporal lobectomy with amygdalohippocampectomy and selective amygdalohippocampectomy.

We provide a historical overview of laser interstitial thermal therapy development and the technological advancements that led to the currently available commercial systems. Current applications of MRg-LITT for MTLE, reported outcomes, and technical issues of the surgical procedure are reviewed. Although initial reports indicate that stereotactic laser amygdalohippocampotomy may be a safe and effective therapy for medically refractory MTLE, further research is required to establish its long-term effectiveness and its cost/benefit profile.

Posted on

Electrical stimulation of the parahippocampal gyrus for prediction of posthippocampectomy verbal memory decline

provocative-test-for-verbal-memory-decline

J Neurosurg 125:1053–1060, 2016

Epilepsy surgery is of known bene t for drug-resistant temporal lobe epilepsy (TLE); however, a certain number of patients suffer signi cant decline in verbal memory after hippocampectomy. To prevent this disabling compli- cation, a reliable test for predicting postoperative memory decline is greatly desired. Therefore, the authors assessed the value of electrical stimulation of the parahippocampal gyrus (PHG) as a provocation test of verbal memory decline after hippocampectomy on the dominant side.

Methods Eleven right-handed, Japanese-speaking patients with medically intractable left TLE participated in the study. Before surgery, they underwent provocative testing via electrical stimulation of the left PHG during a verbal en- coding task. Their pre- and posthippocampectomy memory function was evaluated according to the Wechsler Memory Scale-Revised (WMS-R) and/or Mini-Mental State Examination (MMSE) before and 6 months after surgery. The rela- tionship between postsurgical memory decline and results of the provocative test was evaluated.

Results Left hippocampectomy was performed in 7 of the 11 patients. In 3 patients with a positive provocative rec- ognition test, verbal memory function, as assessed by the WMS-R, decreased after hippocampectomy, whereas in 4 patients with a negative provocative recognition test, verbal memory function, as assessed by the WMS-R or MMSE, was preserved.

Conclusions Results of the present study suggest that electrical stimulation of the PHG is a reliable provocative test to predict posthippocampectomy verbal memory decline.

 

Posted on

The evolving utility of diffusion tensor tractography in the surgical management of temporal lobe epilepsy

the-evolving-utility-of-diffusion-tensor-tractography-in-the-surgical-management-of-temporal-lobe-epilepsy

Acta Neurochir (2016) 158:2185–2193

Diffusion tensor imaging (DTI) is a relatively new imaging modality that has found many peri-operative applications in neurosurgery.

Methods A comprehensive survey of the applications of diffusion tensor imaging (DTI) in planning for temporal lobe epilepsy surgery was conducted. The presentation of this literature is supplemented by a case illustration.

Results The authors have found that DTI is well utilized in epilepsy surgery, primarily in the tractography of Meyer’s loop. DTI has also been used to demonstrate extratemporal connections that may be responsible for surgical failure as well as perioperative planning. The tractographic anatomy of the temporal lobe is discussed and presented with original DTI pictures.

Conclusions The uses of DTI in epilepsy surgery are varied and rapidly evolving. A discussion of the technology, its limitations, and its applications is well warranted and presented in this article.

Posted on

Rates and Predictors of Seizure Freedom With Vagus Nerve Stimulation for Intractable Epilepsy

vnsdevice

Neurosurgery 79:345–353, 2016

Neuromodulation-based treatments have become increasingly important in epilepsy treatment. Most patients with epilepsy treated with neuromodulation do not achieve complete seizure freedom, and, therefore, previous studies of vagus nerve stimulation (VNS) therapy have focused instead on reduction of seizure frequency as a measure of treatment response.

OBJECTIVE: To elucidate rates and predictors of seizure freedom with VNS.

METHODS: We examined 5554 patients from the VNS therapy Patient Outcome Registry, and also performed a systematic review of the literature including 2869 patients across 78 studies.

RESULTS: Registry data revealed a progressive increase over time in seizure freedom after VNS therapy. Overall, 49% of patients responded to VNS therapy 0 to 4 months after implantation ($50% reduction seizure frequency), with 5.1% of patients becoming seizure-free, while 63% of patients were responders at 24 to 48 months, with 8.2% achieving seizure freedom. On multivariate analysis, seizure freedom was predicted by age of epilepsy onset .12 years (odds ratio [OR], 1.89; 95% confidence interval [CI], 1.38- 2.58), and predominantly generalized seizure type (OR, 1.36; 95% CI, 1.01-1.82), while overall response to VNS was predicted by nonlesional epilepsy (OR, 1.38; 95% CI, 1.06- 1.81). Systematic literature review results were consistent with the registry analysis: At 0 to 4 months, 40.0% of patients had responded to VNS, with 2.6% becoming seizurefree, while at last follow-up, 60.1% of individuals were responders, with 8.0% achieving seizure freedom.

CONCLUSION: Response and seizure freedom rates increase over time with VNS therapy, although complete seizure freedom is achieved in a small percentage of patients.

Posted on

Selective amygdalohippocampectomy via trans-superior temporal gyrus keyhole approach

Selective amygdalohippocampectomy via trans-superior temporal gyrus keyhole approach

Acta Neurochir (2016) 158:785–789

Hippocampal sclerosis is the most common cause of drug-resistant epilepsy amenable for surgical treatment and seizure control. The rationale of the selective amygdalohippocampectomy is to spare cerebral tissue not included in the seizure generator.

Method Describe the selective amygdalohippocampectomy through the trans-superior temporal gyrus keyhole approach.

Conclusion Selective amygdalohippocampectomy for temporal lobe epilepsy is performed when the data (semiology, neuroimaging, electroencephalography) point to the mesial temporal structures. The trans-superior temporal gyrus keyhole approach is a minimally invasive and safe technique that allows disconnection of the temporal stem and resection of temporomesial structures.

Posted on

Robot-Assisted Stereoelectroencephalography

Robot-Assisted Stereoelectroencephalography

Neurosurgery 78:169–180, 2016

Robot-assisted stereoelectroencephalography (SEEG) may represent a simplified, precise, and safe alternative to the more traditional SEEG techniques.

OBJECTIVE: To report our clinical experience with robotic SEEG implantation and to define its utility in the management of patients with medically refractory epilepsy.

METHODS: The prospective observational analyses included all patients with medically refractory focal epilepsy who underwent robot-assisted stereotactic placement of depth electrodes for extraoperative brain monitoring between November 2009 and May 2013. Technical nuances of the robotic implantation technique are presented, as well as an analysis of demographics, time of planning and procedure, seizure outcome, in vivo accuracy, and procedure-related complications.

RESULTS: One hundred patients underwent 101 robot-assisted SEEG procedures. Their mean age was 33.2 years. In total, 1245 depth electrodes were implanted. On average, 12.5 electrodes were implanted per patient. The time of implantation planning was 30 minutes on average (range, 15-60 minutes). The average operative time was 130 minutes (range, 45-160 minutes). In vivo accuracy (calculated in 500 trajectories) demonstrated a median entry point error of 1.2 mm (interquartile range, 0.78-1.83 mm) and a median target point error of 1.7 mm (interquartile range, 1.20-2.30 mm). Of the group of patients who underwent resective surgery (68 patients), 45 (66.2%) gained seizure freedom status. Mean follow-up was 18 months. The total complication rate was 4%.

CONCLUSION: The robotic SEEG technique and method were demonstrated to be safe, accurate, and efficient in anatomically defining the epileptogenic zone and subsequently promoting sustained seizure freedom status in patients with difficult-to- localize seizures.

Posted on

Temporal lobe epilepsy and cavernous malformations: surgical strategies and long-term outcomes

Temporal lobe epilepsy and cavernous malformations- surgical strategies and long-term outcomes

Acta Neurochir (2015) 157:1887–1895

Cerebral cavernous malformations (CCM) of the temporal lobe often present with seizures. Surgical resection of these lesions can offer durable seizure control. There is, however, no universally accepted methodology for assessing and surgically treating these patients. We propose an algorithm to maximize positive surgical outcomes (seizure control) while minimizing post-surgical neurological deficit.

Methods A retrospective review of 34 patients who underwent epilepsy surgery for radiographically proven temporal lobe CCM was conducted. Patients underwent a relatively standard work-up for seizure localization. In patients with mesial temporal lobe epilepsy (MTLE), a complete resection of the epileptogenic zone was performed including amygdalo-hippocampectomy in addition to a lesionectomy if not contraindicated by pre-operative work-up. Patients with neocortical epilepsy underwent intraoperative electrocorticography (ECoG)-guided lesionectomy.

Results Seizure-free rate for mesial and neocortical (anterior, lateral, and basal) location was 90 vs. 83 %, respectively. Complete resection of the lesion, irrespective of location, was statistically significant for seizure control (p=0.018). There was no difference in seizure control based on disease duration or location (p>0.05). Patients with mesial temporal CCM who presented with MTLE were presumed to also have mesial temporal sclerosis (MTS), or dual pathology. These patients underwent routine resection of the mesial structures. Interestingly, patients who had MTLE and basal (neocortical) lesions who underwent a mesial resection for suspected MTS were found not to have dual pathology.

Conclusions Patients with temporal lobe CCM should be offered resection for durable seizure control, prevention of secondary epileptogenic foci, and elimination of hemorrhage risk. The preoperative work-up should follow a team approach. Surgical intervention should include complete lesionectomy in all cases. Intra or extra-operative ECoG for neocortical lesions may be beneficial. Management of mesial temporal CCMs (archicortex) should consider resection of a well-defined epileptogenic zone (including mesial structures) due to high probability of pathologically proven MTS. The use of this treatment algorithm is useful for the education and treatment of these patients.

Keywords Epilepsy , Cavernous malformation, Temporal lobe , Pathology

Posted on

Statistical shape analysis of temporal lobe in mesial temporal sclerosis patients

Statistical shape analysis of temporal lobe in mesial temporal sclerosis patients

Acta Neurochir (2015) 157:1897–1903

Surgery is regarded as a common treatment option for patients with mesial temporal lobe epilepsy due to hippocampal sclerosis but sometimes deciding this diagnosis can be very difficult. We aim to investigate the shape differences in the temporal lobe of mesial temporal sclerosis epilepsy patients compared with healthy controls, investigating the side difference and, if present, assessing the clinical application of this situation.

Method The MRI scans of mesial TLE patients and controls were retrospectively reviewed. Temporal lobe data were collected from the two-dimensional digital images. Standard anthropometric landmarks were selected and marked on each digital image using TPSDIG 2.04 software. Eight anatomic landmarks were marked on images. A generalized Procrustes analysis was used to evaluate the shape difference. The shape deformation of the temporal lobe from control to patient was evaluated using the TPS method.

Results There were statistically significant TL shape differences between groups. High level deformations for the left and right side from the control to patient group were seen in the TPS graphic. The highest deformation was determined at the inferior lateral temporal midpoint of the middle temporal gyri and superior temporal landmark points of both the right and left sides.

Conclusion Our study for the first time demonstrated temporal shape differences in TLE patients using a landmark-based geometrical morphometric method by taking into consideration the topographic distribution of TL.

Posted on

Posterior callosotomy in the semi-prone park-bench position

Posterior callosotomy using a parietooccipital interhemispheric approach in the semi-prone park-bench position-1

J Neurosurg 123:1322–1325, 2015

A 2-stage corpus callosotomy is accepted as a palliative procedure for patients older than 16 years with, in particular, medically intractable generalized epilepsy and drop attack seizures and is preferable for a lower risk of disconnection syndrome.

Although the methods by which a previously performed craniotomy can be reopened for posterior callosotomy have already been reported, posterior corpus callosotomy using a parietooccipital interhemispheric approach with the patient in a semi-prone park-bench position has not been described in the literature.

Here, the authors present a surgical technique for posterior callosotomy using a parietooccipital interhemispheric approach with a semi-prone parkbench position as a second surgery. Although this procedure requires an additional skin incision in the parietooccipital region, it makes the 2-stage callosotomy safer and easier to perform because of reduced intracranial adhesion, less bleeding, and an easier approach to the splenium of the corpus callosum.

Posted on

Seizures Outcome After Stereoelectroencephalography-Guided Thermocoagulations in Malformations of Cortical Development Poorly Accessible to Surgical Resection

Seizures Outcome After Stereoelectroencephalography-Guided Thermocoagulations in Malformations of Cortical Development Poorly Accessible to Surgical Resection

Neurosurgery 77:9–15, 2015

Radiofrequency thermocoagulation (RFTC) guided by stereoelectroencephalography (SEEG) has proved to be a safe palliative method to reduce seizure frequency in patients with drug-resistant partial epilepsy. In malformation of cortical development (MCD), increasing the number of implanted electrodes over that needed for mapping of the epileptogenic zone could help to maximize RFTC efficiency.

OBJECTIVE: To evaluate the benefit of SEEG-guided RFTC in 14 patients suffering from drug-resistant epilepsy related to MCD located in functional cortical areas or in regions poorly accessible to surgery.

METHODS: Ten men and 4 women were treated by RFTC. Thermolesions were produced by applying a 50-V, 120-mA current for 10 to 30 seconds within the epileptogenic zone as identified by the SEEG investigation.

RESULTS: An average of 25.8 ± 17.5 thermolesions were made per procedure. The median follow-up after the procedure was 41.7 months. Sixty-four percent of the patients experienced a long-term decrease in seizure frequency of .50%, of whom 6 (43%) presented long-lasting freedom from seizure. When a focal low-voltage fast activity was present at seizure onset on SEEG recordings, 87.5% of patients were responders or seizure free. All of the patients in whom electric stimulation reproduced spontaneous seizures were responders.

CONCLUSION: Our results show the good benefit-risk ratio of the SEEG-guided procedure for patients suffering from MCD in whom surgery is risky. This study identifies 2 factors, focal low-voltage, high-frequency activity at seizure onset and lowered epileptogenic threshold in the coagulated area, that could be predictive of a favorable seizure outcome after RFTC.

Proudly powered by WordPress