Neuronavigation-Guided Transcortical-Transventricular Endoport-Assisted Endoscopic Resection for Thalamic Lesions: Preliminary Experience.

BACKGROUND: Surgery for thalamic lesions is generally challenging because they are deep-seated lesions surrounded by vital neurovascular structures. Whether neuronavigation-guided transcortical-transventricular endoport-assisted endoscopic resection for thalamic lesions is feasible remains to be further evaluated. METHODS: A retrospective review of 8 who patients received neuronavigation-guided transcortical-transventricular endoport-assisted endoscopic resection for thalamic lesions was performed. Preoperative and tumor-related variables and postoperative outcomes were analyzed. RESULTS: All lesions were located in the medial part of the thalamus, and most of them expanded forward, downward, or backward. Median size of lesions was 31 mm (range, 16-52 mm). Final pathology results confirmed that 1 case was a cavernous malformation, 3 were pilocytic astrocytomas, and 4 were glioblastomas. None of the patients had postoperative seizures. Gross total resection and long-term postoperative survival were achieved in all patients with benign lesions, while near-total resection (>90%) was achieved in 3 of 4 patients (75%) with glioblastoma, and subtotal resection (<90%) was achieved in 1 patient (25%). Among patients with glioblastoma, 1 patient remained free of recurrence at 16 months of follow-up; the other 3 patients had worse Karnofsky performance scale scores after surgery and died within 6 months. CONCLUSIONS: Combining the advantages of neuronavigation, endoscopy, and endoport techniques via the middle frontal gyrus approach can safely and effectively remove benign lesions in the medial part of the thalamus. This procedure can also be performed in well-selected cases of glioblastoma and likely confers a survival advantage for this rapidly and universally fatal disease.

Anatomic, qualitative, and quantitative evaluation of the variants of the infratentorial supracerebellar approach to the posteroinferior thalamus.

The posteroinferior region of the thalamus is formed by the pulvinar, and it is surgically accessed through the infratentorial supracerebellar approach, between the midline and the retromastoid region. This study aimed to compare the paramedian, lateral, extreme lateral, and contralateral paramedian corridors with the posteroinferior thalamus through a suboccipital craniotomy and an infratentorial supracerebellar access. Ten cadavers were studied, and the microsurgical dissections were accompanied by the measurement of the variables using a neuronavigation system. Statistical analysis was performed using analysis of variance (ANOVA). The distance between the access midpoint at the cranial surface and pulvinar varied between 53.3 and 53.9 mm, the contralateral access being an exception (59.9 mm). The vertical angle ranged from 20.6° in the contralateral access to 23.5° in the lateral access. There was a gradual increase in the horizontal angle between the paramedian (17.4°), lateral (31.3°), and extreme lateral (43.7°) accesses. But, this angle in the contralateral access was 14.6°, similar to that of the paramedian access. The exposed area of the thalamus was 125.1 mm2 in the paramedian access, 141.8 mm2 in the lateral access, and 165.9 mm2 in the extreme lateral access, which was similar to that of the contralateral access (164.9 mm2). The horizontal view angle increased with lateralization of the access, which facilitated microscopic visualization. With regard to the exposure of the microsurgical anatomy, the extreme lateral and contralateral accesses circumvent the neural and vascular obstacles at the midline, allowing a larger area of anatomical exposure.

Neuronavigation based 10 sessions of repetitive transcranial magnetic stimulation therapy in chronic migraine: an exploratory study.

INTRODUCTION: Chronic migraine is a disease of altered cortical excitability. Repetitive transcranial magnetic stimulation provides a novel non-invasive method to target the nociceptive circuits in the cortex. Motor cortex is one such potential target. In this study, we targeted the left motor cortex using fMRI-guided neuronavigation. MATERIALS AND METHODS: Twenty right-handed patients were randomized into real and sham rTMS group. Baseline subjective pain assessments were done using visual analog scale (VAS) and questionnaires: State-Trait Anxiety Inventory, Becks Depression Inventory, and Migraine Disability Assessment (MIDAS) questionnaire. Objectively, pain was assessed by means of thermal pain thresholds using quantitative sensory testing. For corticomotor excitability parameters, resting motor thresholds and motor-evoked potentials were mapped. For rTMS total, 600 pulses in 10 trains at 10 Hz with an intertrain interval of 60 s were delivered in each session. Ten such sessions were given 5 days per week over 2 consecutive weeks. The duration of each session was 10 min. Real rTMS was administered at 70% of Resting MT. All the tests were repeated post-intervention and after 1 month of follow-up. There are no studies reporting the use of fMRI-based TMS for targeting the motor cortex in CM patients. RESULTS: We observed a significant reduction in the mean VAS rating, headache frequency, and MIDAS questionnaire in real rTMS group which was maintained after 1 month of follow-up. CONCLUSION: Ten sessions of fMRI-based rTMS over the left motor cortex may provide long-term pain relief in CM, but further studies are warranted to confirm our preliminary findings.

MR Navigation and Tractography-Assisted Transcranial Neuroendoscopic Aspiration of Pediatric Thalamic Abscess.

AIM: Management of thalamic abscess is being considered as a contentious issue in neurosurgery. Regarding these lesions, besides removing the abscess, the most minimal morbidity is targeted during surgery and planning. MATERIAL AND METHOD: A 5-year-old female presented with the symptoms of altered consciousness and left hemiparesis. Her medical history pointed out that she was being followed up for a congenital cardiac anomaly consisting of transposition of the great arteries and a ventricular septal defect. A cranial MRI revealed 2 masses with peripheral contrast enhancement in the right frontal and thalamic regions. She was operated immediately and the right frontal mass, compatible with abscess, was totally excised with frontal mini craniotomy. The patient was hospitalized and followed up under intensive parenteral antibiotics. Control cranial imaging revealed progression in the size of the thalamic abscess, which was corroborative with the increased left hemiparesis. MR tractography was obtained and the patient underwent MR navigation and tractography combined neuronavigation-assisted transcranial neuroendoscopic aspiration of the thalamic abscess. RESULTS: The patient was stable in the early and late postoperative periods and her hemiparesis showed a dramatic recovery with no additional neurological deficits. CONCLUSION: Neuronavigation is considered as one of the techniques that aid the neurosurgeon to augment the success of surgery and minimize the morbidity, especially in critically localized lesions, i.e., eloquent areas. Combining MR navigation with MR tractography images and using them during neuronavigation to assist endoscopic procedures may decrease the surgical morbidity as much as possible.

Is Gross Total Resection Reasonable in Adults with Craniopharyngiomas with Hypothalamic Involvement?

OBJECTIVE: The treatment of hypothalamus-invading craniopharyngiomas, based on pediatric experience, is subtotal resection (STR) with radiotherapy. This strategy sometimes leads to uncontrollable tumor progression. In adults, with the use of endoscopic endonasal surgery (EES), does removing the hypothalamic part of the tumor-whenever possible-compromise the outcome of the patients? METHODS: We included adults with craniopharyngioma treated by a first EES in 2008-2016 by senior neurosurgeon (E.J.). Endocrine, ophthalmologic, and hypothalamic data were retrospectively collected, including body mass index (BMI), cognitive and social status, with a systematic follow-up interview. Magnetic resonance imaging scans were graded according to Puget classification: 0, no hypothalamic involvement; 1, hypothalamic displacement; and 2, hypothalamic involvement. Grade 2 tumors were separated into gross total resection (GTR) or STR. RESULTS: We included 22 patients aged 18-79 years. Presenting symptoms were visual (14, 64%), endocrine dysfunction (10, 45%), BMI >30 (8, 36%), and cognitive/psychiatric impairment (9, 41%). Fourteen (64%) were grade 2 craniopharyngiomas. GTR was performed in 14 (64%) patients. Postoperatively, 12/14 (86%) cases improved visually, and 20 (91%) needed hormone replacement therapy. There was no difference in BMI evolution in the GTR versus STR group, cognitive status was stable or improved in all patients except 1; 4/8 patients with STR experienced progression needing adjuvant treatment versus no patient with GTR. CONCLUSIONS: EES GTR of grade 2 craniopharyngiomas does not cause major hypothalamic worsening, in contrast with children operated by cranial approaches. The surgeon's experience is key in deciding when to stop the dissection. Offering GTR whenever possible aims at avoiding tumor progression and radiotherapy.

Image Guidance for Ventricular Shunt Surgery: An Analysis of Hospital Charges.

BACKGROUND: Image guidance for shunt surgery results in more accurate proximal catheter placement. However, reduction in shunt failure remains unclear in the literature. There have been no prior studies evaluating the cost effectiveness of neuronavigation for shunt surgery. OBJECTIVE: To perform a cost analysis using available hospital charges of hypothetical shunt surgery performed with/without electromagnetic neuronavigation (EMN). METHODS: Hospital charges were collected for physician fees, radiology, operating room (OR) time and supplies, postanesthesia care unit, hospitalization days, laboratory, and medications. Index shunt surgery charges (de novo or revision) were totaled and the difference calculated. This difference was compared with hospital charges for shunt revision surgery performed under 2 clinical scenarios: (1) same hospital stay as the index surgery; and (2) readmission through the emergency department. RESULTS: Costs for freehand de novo and revision shunt surgery were $23 946.22 and $23 359.22, respectively. For stealth-guided de novo and revision surgery, the costs were $33 646.94 and $33 059.94, a difference of $9700.72. The largest charge increase was due to additional OR time (34 min; $4794), followed by disposable EMN equipment ($2672). Total effective charges to revise the shunt for scenarios 1 and 2 were $34 622.94 and $35 934.94, respectively. The cost ratios between the total revision charges for both scenarios and the difference in freehand vs EMN-assisted shunt surgery ($9700.72) were 3.57 and 3.70, respectively. CONCLUSION: From an economic standpoint and within the limitations of our models, the number needed to prevent must be 4 or less for the use of neuronavigation to be considered cost effective.

MR-Guided Laser Interstitial Thermal Therapy for Medically Refractory Lesional Epilepsy in Pediatric Patients: Experience and Outcomes.

INTRODUCTION: MR-guided laser interstitial thermal therapy (MRgLITT) has emerged as a safe and effective treatment option for the ablation of epileptic foci. Its minimally invasive nature makes it attractive due to decreased morbidity and hospital stay. OBJECTIVE: To report the efficacy and safety of MRgLITT as a minimally invasive procedure for the ablation of epileptic foci in the pediatric population of medically refractory lesional epilepsy. METHODS: A retrospective review of patients who underwent MRgLITT via Visualase laser ablation at a single pediatric center was performed. Demographic and outcome data were compiled and analyzed. RESULTS: Twelve pediatric patients with a total 18 lesions underwent MRgLITT procedures between December 2013 and September 2017. Mean age at surgery was 11.1 years. Surgical substrates included 4 hypothalamic hamartomas, 3 periventricular heterotopias, 2 deep focal cortical dysplasias, 2 tuberous sclerosis, and 1 mesial temporal sclerosis. Methods of stereotaxis used included Leksell frame, BrainLab VarioGuide, ROSA robot guidance, and ClearPoint navigation. Mean procedure length was 250 min, and mean length of stay was 1.3 days. After treatment, 8 patients were seizure free (Engel I, 66.7%), 2 patients demonstrated significant improvement (Engel II, 16.7%), and 2 patients showed worthwhile improvement (Engel III, 16.7%). One patient developed a left superior quadrantanopsia postoperatively. Mean follow-up duration was 10 months. CONCLUSION: This study contributes to the sparse literature in this field by demonstrating the high efficacy and low morbidity of MRgLITT as a minimally invasive method of ablation of epileptic foci in the pediatric population of medically refractory lesional epilepsy.

Application of an individualized and reassemblable 3D printing navigation template for accurate puncture during sacral neuromodulation.

OBJECTIVE: To evaluate the feasibility and safety of an individualized and reassemblable three-dimensional (3D) printing navigation template for making accurate punctures during sacral neuromodulation (SNM). METHODS: From July 2016 to July 2017, 24 patients undergoing SNM were enrolled. Conventional X-ray guidance was used in the control group, which included 14 patients, while the 3D printing template was used in the experimental group, which included 10 patients. The number of punctures, the average puncture time, the exposure to X-ray, the adjustment time during the operation and the testing of the SNM device, the infection and haemorrhage rate, and the implantable pulse generator (IPG) implantation rates were compared between the two groups. RESULTS: In total, 24 patients successfully underwent stage I. When comparing the control group and the experimental group, the number of punctures were 9.6 ± 7.7 and 1.5 ± 0.7, respectively; the average puncture times were 35.4 ± 14.6 and 4.1 ± 2.2 min, respectively; and the X-ray exposure levels were 8.37 ± 4.83 mAs and 2.34 ± 0.54 mAs, respectively. No postoperative complications were reported in either group. The IPG implantation rates were not different between the two groups. CONCLUSION: The 3D printing template for SNM can help us to perform accurate and quick punctures into the target sacral foramina, reduce X-ray exposure, and shorten the operation time. For patients with obesity, sacral variation, sacral bone fractures or losses and for patients who are unable to tolerate the prone position during operation, use of the 3D printing template is recommended.

The Clinical Efficacy of Electromagnetic Navigation-Guided Hematoma Puncture Drainage in Patients with Hypertensive Basal Ganglia Hemorrhage.

OBJECTIVE: To investigate the clinical efficacy of navigation-guided minimally invasive surgery in patients with hypertensive basal ganglia hemorrhage. METHODS: A total of 64 patients with hypertensive basal ganglia hemorrhage were enrolled in this retrospective study. They were divided into a navigation group and a traditional group based on surgical approaches. The data for the 2 groups of patients were analyzed with regard for the hematoma clearance rate, duration of surgery, duration of hospitalization, Glasgow Outcome Scale score at discharge, Barthel index score at 6 months, and postoperative complication rates for rebleeding and pneumonia. RESULTS: There were no significant differences in basic characteristics between the 2 groups (P > 0.05). The hematoma clearance rate was significantly lower in the navigation group (49.18 ± 16.76%) than in the traditional group (84.29 ± 6.91%, P < 0.01). The duration of surgery and duration of hospitalization were significantly shorter in the navigation group (55.00 ± 11.89 minutes and 24.25 ± 7.1 days, respectively) than in the traditional group (156.38 ± 47.9 minutes and 32.63 ± 9.8 days, respectively; both P < 0.01). There were also significant differences between the 2 groups in Glasgow Outcome Scale scores (P = 0.006). The Barthel index scores were significantly greater in the navigation group (73.13 ± 18.76) than in the traditional group (57.63 ± 26.63, P < 0.05). There were no significant differences between the 2 groups in the complication rates (P > 0.05). CONCLUSIONS: Under certain conditions, compared with standard craniotomy and hematoma evacuation, navigation-guided hematoma puncture aspiration and catheter drainage is simple, effective, and safe as a treatment for hypertensive basal ganglia hemorrhage.

Development and validation of a 3D-printed neuronavigation headset for therapeutic brain stimulation.

BACKGROUND: Accurate neuronavigation is essential for optimal outcomes in therapeutic brain stimulation. MRI-guided neuronavigation, the current gold standard, requires access to MRI and frameless stereotaxic equipment, which is not available in all settings. Scalp-based heuristics depend on operator skill, with variable reproducibility across operators and sessions. An intermediate solution would offer superior reproducibility and ease-of-use to scalp measurements, without requiring MRI and frameless stereotaxy. OBJECTIVE: We present and assess a novel neuronavigation method using commercially-available, inexpensive 3D head scanning, computer-aided design, and 3D-printing tools to fabricate form-fitted headsets for individuals that hold a stimulator, such as an rTMS coil, in the desired position over the scalp. METHODS: 20 individuals underwent scanning for fabrication of individualized headsets designed for rTMS of the left dorsolateral prefrontal cortex (DLPFC). An experienced operator then performed three trials per participant of three neuronavigation methods: MRI-guided, scalp-measurement (BeamF3 method), and headset placement, and marked the sites obtained. Accuracy (versus MRI-guidance) and reproducibility were measured for each trial of each method. RESULTS: Within-subject accuracy (against a gold-standard centroid of three MRI-guided localizations) for MRI-guided, scalp-measurement, and headset methods was 3.7 ± 1.6 mm, 14.8 ± 7.1 mm, and 9.7 ± 5.2 mm respectively, with headsets significantly more accurate (M = 5.1, p = 0.008) than scalp-measurement methods. Within-subject reproducibility (against the centroid of 3 localizations in the same modality) was 3.7 ± 1.6 mm (MRI), 4.2 ± 1.4 (scalp-measurement), and 1.4 ± 0.7 mm (headset), with headsets achieving significantly better reproducibility than either other method (p < 0.0001). CONCLUSIONS: 3D-printed headsets may offer good accuracy, superior reproducibility and greater ease-of-use for stimulator placement over DLPFC, in settings where MRI-guidance is impractical.

Microsurgical anatomy of the subthalamic nucleus: correlating fiber dissection results with 3-T magnetic resonance imaging using neuronavigation.

OBJECTIVE: Despite the extensive use of the subthalamic nucleus (STN) as a deep brain stimulation (DBS) target, unveiling the extensive functional connectivity of the nucleus, relating its structural connectivity to the stimulation-induced adverse effects, and thus optimizing the STN targeting still remain challenging. Mastering the 3D anatomy of the STN region should be the fundamental goal to achieve ideal surgical results, due to the deep-seated and obscure position of the nucleus, variable shape and relatively small size, oblique orientation, and extensive structural connectivity. In the present study, the authors aimed to delineate the 3D anatomy of the STN and unveil the complex relationship between the anatomical structures within the STN region using fiber dissection technique, 3D reconstructions of high-resolution MRI, and fiber tracking using diffusion tractography utilizing a generalized q-sampling imaging (GQI) model. METHODS: Fiber dissection was performed in 20 hemispheres and 3 cadaveric heads using the Klingler method. Fiber dissections of the brain were performed from all orientations in a stepwise manner to reveal the 3D anatomy of the STN. In addition, 3 brains were cut into 5-mm coronal, axial, and sagittal slices to show the sectional anatomy. GQI data were also used to elucidate the connections among hubs within the STN region. RESULTS: The study correlated the results of STN fiber dissection with those of 3D MRI reconstruction and tractography using neuronavigation. A 3D terrain model of the subthalamic area encircling the STN was built to clarify its anatomical relations with the putamen, globus pallidus internus, globus pallidus externus, internal capsule, caudate nucleus laterally, substantia nigra inferiorly, zona incerta superiorly, and red nucleus medially. The authors also describe the relationship of the medial lemniscus, oculomotor nerve fibers, and the medial forebrain bundle with the STN using tractography with a 3D STN model. CONCLUSIONS: This study examines the complex 3D anatomy of the STN and peri-subthalamic area. In comparison with previous clinical data on STN targeting, the results of this study promise further understanding of the structural connections of the STN, the exact location of the fiber compositions within the region, and clinical applications such as stimulation-induced adverse effects during DBS targeting.

Perioperative functional neuroimaging of gliomas in eloquent brain areas.

Surgical resection of gliomas involving eloquent brain areas must be maximal in order to improve patients' survival, and safe to prevent postoperative impairments. Therefore, the precise spatial relationship between the lesion and eloquent brain areas needs to be established. Functional magnetic resonance imaging and diffusion tensor imaging are robust methods with increasing indications in neurosurgery for past decade. The aim of this review article is not only to pinpoint the major limitations of these methods in order to avoid erroneous conclusions, but also to detail practical aspects associated with the main paradigms routinely used in functional magnetic resonance imaging, and to discuss recent validation of functional magnetic resonance imaging and diffusion tensor imaging results with direct electrical stimulation during awake surgery.

Resection of cavernous angioma located in eloquent areas using functional cortical and subcortical mapping under awake conditions. Outcomes in a 50-case multicentre series.

INTRODUCTION: Surgical resection of supratentorial cavernous angiomas located in eloquent areas poses a significant risk to the patient of postoperative neurological impairment and justifies intraoperative functional monitoring. METHODS: Multicentre retrospective series of adult patients with cavernous angiomas located within eloquent areas and treated with functional-based surgical resection according to functional boundaries under intraoperative functional cortico-subcortical monitoring under awake conditions. RESULTS: Fifty patients (18 males, mean 36.3±10.8 year-old) underwent surgical resection with intraoperative cortico-subcortical functional mapping using direct electrostimulation under awake conditions for a cavernous angioma located in eloquent areas with a mean postoperative follow-up of 21.0±21.2 months. At presentation, the cavernous angioma had previously resulted in severe impairment (neurological deficit in 34%, seizures in 70%, uncontrolled seizures in 34%, reduced Karnofsky Performance Status score of 70 or less in 24%, inability to work in 52%). Functional-based surgical resection allowed complete removal of the cavernous angioma in 98% and of the haemosiderin rim in 82%. Postoperative seizures and other complications were rare, and similarly so across all centres included in this series. Postoperatively, we found functional improvement in 84% of patients (reduced Karnofsky Performance Status score of 70 or less in 6%, uncontrolled seizures in 16%, and inability to work in 11%). CONCLUSION: Functional-based surgical resection aids the safe and complete resection of cavernous angiomas located in eloquent areas while minimizing the surgical risks. Functional mapping has to be considered in such challenging cases.

Image guidance based on MRI for spinal interstitial laser thermotherapy: technical aspects and accuracy.

OBJECTIVE Image guidance for spinal procedures is based on 3D-fluoroscopy or CT, which provide poor visualization of soft tissues, including the spinal cord. To overcome this limitation, the authors developed a method to register intraoperative MRI (iMRI) of the spine into a neuronavigation system, allowing excellent visualization of the spinal cord. This novel technique improved the accuracy in the deployment of laser interstitial thermal therapy probes for the treatment of metastatic spinal cord compression. METHODS Patients were positioned prone on the MRI table under general anesthesia. Fiducial markers were applied on the skin of the back, and a plastic cradle was used to support the MRI coil. T2-weighted MRI sequences of the region of interest were exported to a standard navigation system. A reference array was sutured to the skin, and surface matching of the fiducial markers was performed. A navigated Jamshidi needle was advanced until contact was made with the dorsal elements; its position was confirmed with intraoperative fluoroscopy prior to advancement into a target in the epidural space. A screenshot of its final position was saved, and then the Jamshidi needle was exchanged for an MRI-compatible access cannula. MRI of the exact axial plane of each access cannula was obtained and compared with the corresponding screenshot saved during positioning. The discrepancy in millimeters between the trajectories was measured to evaluate accuracy of the image guidance RESULTS Thirteen individuals underwent implantation of 47 laser probes. The median absolute value of the discrepancy between the location predicted by the navigation system and the actual position of the access cannulas was 0.7 mm (range 0-3.2 mm). No injury or adverse event occurred during the procedures. CONCLUSIONS This study demonstrates the feasibility of image guidance based on MRI to perform laser interstitial thermotherapy of spinal metastasis. The authors' method permits excellent visualization of the spinal cord, improving safety and workflow during laser ablations in the epidural space. The results can be extrapolated to other indications, including biopsies or drainage of fluid collections near the spinal cord.

Endoscopic management of a low-grade thalamic glioma: a safe alternative to open microsurgery?

BACKGROUND: Despite considerable advances in preoperative and intraoperative imaging and neuronavigation, resection of thalamic gliomas remains challenging. Although both endoscopic biopsy and third ventriculostomy (ETV) for the treatment of secondary hydrocephalus are commonly performed, endoscopic resection of thalamic gliomas has been very sparsely described. METHOD: We report and illustrate the surgical procedure and patient's outcome after full endoscopic resection of a thalamic glioma and to discuss this approach as an alternative to open microsurgery. RESULTS: In 2016, a 56-year-old woman presented with disorientation, dysphasia and right facial hypaesthesia in our department. Cranial magnetic resonance imaging revealed a left thalamic lesion and subsequent hydrocephalus. Initially, hydrocephalus was treated by ETV but forceps biopsy was not diagnostic. However, metabolism in 18F-fluoroethyl-L-tyrosine positron emission tomography indicated glioma. Subsequently, endoscopic and neuronavigation-guided tumour resection was performed using a <1 cm2, trans-sulcal approach through the left posterior horn of the lateral ventricle. While visibility was poor using the intraoperative microscope, neuroendoscopy provided excellent visualisation and allowed safe tumour debulking. Neither haemorrhage from the tumour or collapse of the cavity compromised endoscopic resection. CONCLUSIONS: In accordance with one previously published case of endoscopic resection of a thalamic glioma, no surgery-related complications were observed. Although this remains to be determined in larger series, endoscopic resection of these lesions might be a safe and feasible alternative to biopsy or open surgery. Future studies should also aim to identify patients specifically eligible for these approaches.

Recovery of long-term paresis following resection of WHO grade II gliomas infiltrating the pyramidal pathway.

Recent publications had reported high rates of preoperative neurological impairments in WHO grade II gliomas (GIIG) that significantly affect the quality of life. Consequently, one step further in the analysis of surgical outcome in GIIG is to evaluate if surgery is capable to improve preoperative deficits. Here are reported two cases of GIIG infiltrating the primary motor cortex and pyramidal pathway that had a long-term paresis before surgery. Both patients were operated with intraoperative electrical stimulation mapping, with identification and preservation of the primary motor cortex and pyramidal tract. Despite the long-lasting paresis, both cases had a significant improvement of motor function after surgery. Knowledge of this potential recovery before surgery is of major significance for planning the surgical strategy in GIIG. Two possible predictors of motor recovery were analyzed: 1) reconstruction of the corticospinal tract with diffusion tensor imaging tractography is indicative of anatomo-functional integrity, despite tract deviation and infiltration; 2) intraoperative identification of motor response by electrostimulation confirms the presence of an intact peritumoral tract. Thus, resection should stop at this boundary even in cases of long lasting preoperative hemiplegia.

Neuronavigation-Assisted Aspiration and Electro-Acupuncture for Hypertensive Putaminal Hemorrhage: A Suitable Technique on Hemiplegia Rehabilitation.

AIM: To identify whether neuronavigation-assisted aspiration (NA) combined with electro-acupuncture (EA) provides better motor recovery in events of hypertensive putaminal hematoma (HPH) sized 30 to 50 ml. This study aims to examine whether neuronavigation-assisted aspiration and electro-acupuncture have additional value to cerebral hemorrhage motor rehabilitation. MATERIAL AND METHODS: 240 patients with HPH sized 30 to 50 ml and admitted within 6 to 10 hours after stroke ictus were included in this study. Group 1 contained 60 patients who underwent neuronavigation-assisted aspiration and electro-acupuncture (NAEA), group 2 contained 60 patients who underwent neuronavigation-assisted aspiration (NA), group 3 contained 60 patients who underwent electro-acupuncture (EA), and group 4 contained 60 patients who received conservative therapy consisting solely of medications. All the patients received the same therapeutic plan on admission and functional exercises three days after stroke onset. Electro-acupuncture was performed on the third day of admission; motor recovery was examined on weeks zero and eight by blinded assessors. Outcome measures included Fugl-Meyer assessment, modified Ashworth Scale and Functional Independence Measure. RESULTS: Group one showed significantly improved motor outcomes compared to group four (p < 0.01). Group one also showed significant motor improvement when pre-and post- therapy functioning was examined (p < 0.01). Cerebral edema and ischemia were significantly decreased in group one compared to group 3 and 4 (p < 0.05). While not as effective as group one treatment, group two and group three patients had significant motor recovery after intervention when compared to group four (p < 0.05). Muscular tension secondary to stroke was considerably improved between group one and group four, group two and group four, group three and group four respectively (p < 0.05). Activities of daily living (ADL) improved a lot with EA together with NA. CONCLUSION: Neuronavigation-assisted aspiration and electro-acupuncture of HPH at the early stage can provide improved motor recovery with fewer complications. Significant motor recovery can be achieved by neuronavigation-assisted aspiration with acupuncture. Based on our findings, we recommend early intervention with NA and EA in order to promote early rehabilitation of hemiplegia secondary to HPH.

Use of a Mobile Intraoperative Computed Tomography Scanner for Navigation Registration During Laser Interstitial Thermal Therapy of Brain Tumors.

OBJECTIVE: In recent years laser interstitial thermal therapy (LITT) has become the ablative neurosurgical procedure of choice. Multiple methods for registration and laser fiber verification have been described, with each method requiring multiple steps and significant time expenditure. We evaluated the use of a commercially available mobile computed tomography (CT) scanner for stereotactic registration during LITT for brain tumors in an attempt to simplify the procedure and improve intraoperative awareness of laser position. METHODS: This is a retrospective chart review comparing LITT of brain tumors in 23 patients undergoing a standard protocol requiring skull pins and transport of the patient to a CT suite to obtain a reference scan compared with 14 patients in whom the Medtronic O-arm was used intraoperatively for navigation registration and confirmation of laser position. RESULTS: Total ablation of the target was achieved in all patients with no surgical complications. Total surgery time was shorter for the O-arm group than for the standard protocol group, once experience was gained with bringing the O-arm in and out of the surgical field. Return from the magnetic resonance imaging suite to the operating room for repositioning of the laser was required for 1 patient in the standard protocol group, but for no patients in the O-arm group. Once experience was gained with using the O-arm, estimated surgical costs were lower for this group. CONCLUSIONS: Use of a mobile intraoperative CT scanner for navigation registration and confirmation of laser position during LITT may play a role in streamlining the procedure and improving patient safety and comfort.

Clinical Significance of Invasive Motor Cortex Stimulation for Trigeminal Facial Neuropathic Pain Syndromes.

BACKGROUND: Invasive neuromodulation of the cortical surface for various chronic pain syndromes has been performed for >20 years. The significance of motor cortex stimulation (MCS) in chronic trigeminal neuropathic pain (TNP) syndromes remains unclear. Different techniques are performed worldwide in regard to operative procedure, stimulation parameters, test trials, and implanted materials. OBJECTIVE: To present the clinical experiences of a single center with MCS, surgical approach, complications, and follow-up as a prospective, noncontrolled clinical trial. METHODS: The implantation of epidural leads over the motor cortex was performed via a burr hole technique with neuronavigation and intraoperative neurostimulation. Special focus was placed on a standardized test trial with an external stimulation device and the implementation of a double-blinded or placebo test phase to identify false-positive responders. RESULTS: A total of 36 patients with TNP were operated on, and MCS was performed. In 26 of the 36 patients (72%), a significant pain reduction from a mean of 8.11 to 4.58 (on the visual analog scale) during the test trial was achieved (P < .05). Six patients were identified as false-positive responders (17%). At the last available follow-up of 26 patients (mean, 5.6 years), active MCS led to a significant pain reduction compared with the preoperative pain ratings (mean visual analog scale score, 5.01; P < .05). CONCLUSION: MCS is an additional therapeutic option for patients with refractory chronic TNP, and significant long-term pain suppression can be achieved. Placebo or double-blinded testing is mandatory. ABBREVIATIONS: MCS, motor cortex stimulationNRS, numeric pain rating scaleTNP, trigeminal neuropathic or deafferentation painVAS, visual analog scale.

Sacral nerve stimulation lead implantation in partial sacral agenesis using intra-operative computerized tomography.

AIM: Sacral nerve stimulation (SNS) lead implantation is a straightforward procedure for individuals with intact spinal vertebrae. When sacral anomalies are present, however, the anatomical and radiological reference points used for the accurate placement of the electrode may be absent or difficult to identify. METHOD: We describe an innovative surgical procedure of percutaneous nerve evaluation for SNS in a patient with faecal incontinence secondary to a congenital imperforate anus and partial sacral agenesis using a surgical imaging platform (O-arm system) under neurophysiological control. RESULTS: Using intra-operative CT and neuronavigation, the insertion point at the skin was identified. The lead was introduced into the right-sided S3 foramen and placed at the correct depth. An appropriate motor response was obtained after stimulation and neurophysiological control confirmed that the right S3 root was being stimulated. CONCLUSION: Our experience showed that O-arm guided navigation can be used to overcome the difficulty of SNS lead placement in patients with partial sacral agenesis who have faecal incontinence.