Early de-tethering: analysis of urological and clinical consequences in a series of 40 children.

PURPOSE: Early de-tethering procedures are performed on spinal dysraphisms to prevent neuro-urological deterioration caused by growth. Partial lipoma removal may cause delayed deterioration by re-tethering, while complete removal may increase the risk of postoperative worsening. The present study evaluates the risk of postoperative deterioration and the protective potential of intraoperative neurophysiological monitoring (IOM), with a special reference to the conus lipomas treated with the radical approach. METHODS: Forty toddlers (< 24 months) underwent complete perioperative neurological and urological assessment, including urodynamic study (UDS). The dysraphisms were subgrouped according to Pang's classification. IOM was applied in all patients: transcranial motor evoked potentials (tMep) combined with mapping were recorded in all cases while bulbocavernosus reflex (BCR) was evaluable just in 7 cases. RESULTS: At preoperative evaluation, 11 children already had UDS impairment and 2 had motor disturbances before neurosurgery. At 1-month follow-up, preoperative motor disturbances were stable, 7/11 UDS alterations normalized, and the remaining 4 were stable. At 6-month follow-up, all motor deficits and 8/11 preoperative UDS alterations had improved. Unfortunately, 7 children with previously normal UDS experienced a new impairment after surgery: 2/7 normalized while 5/7 did not recover. This postoperative permanent urodynamic impairment occurred in 4 chaotic lipoma (CLchaos) and in one terminal myelocystocele (TMC) that means a surgical deterioration rate of 22% for the high risk cases. CONCLUSIONS: This small highly selected series confirms that early de-tethering may stop or revert the spontaneous neuro-urological deterioration: in fact, preoperative UDS impairment was frequent (27.5%) and improved in all the low surgical risk cases (limited dorsal myeloschisis, filar, transitional and dorsal lipomas). On the contrary, in CLchaos and TMC, early de-tethering was unable to revert preoperative UDS impairment, and radical surgery carried a high risk of new neuro-urological deterioration directly caused by the operation. In our experience, IOM had a protective role for motor functions, while it was less effective for the neuro-urological ones, probably due to the anesthesiology regimens applied. In conclusion, among the dysraphisms, CLchoas proved to be the worst enemy that often camouflages at MRI. Affording it without all possible IOM weapons carries a high risk to harm the patient.

Intraoperative compound muscle action potentials (CMAPs) amplitude changes after decompression and neurolysis of peripheral nerves in upper limbs neuropathies: electrophysiologial considerations and relation with clinical outcome.

BACKGROUND: Decompression and, when necessary, neurolysis in entrapment neuropathies of upper limbs are effective and safe procedures, but their correlation with the variation of compound muscle action potentials (CMAPs) is still unclear, based in particular on experimental models. In addition, there are few data regarding the efficacy of intraoperative neurophysiologic monitoring (IOM) to predict clinical early and late outcome after surgery in term of pain control and sensitive/motor recovery. We report about the association between the intraoperative anatomical and neurophysiological findings and the mid- and long-term postoperative clinical course in a surgical series. METHODS: We retrospectively reviewed clinical data of 24 patients among 68 admitted at our Institution for upper limb neuropathies from September 2012 to May 2015. All patients completed two preoperative questionnaires for assessing the level of disability (DASH) and of pain/discomfort (NRS). CMAPs' amplitudes were intraoperatively detected, before and after decompression and neurolysis and the variations were then related to clinical outcome, evaluated through DASH and NRS questionnaires at 6-, 9- and 12-months follow-up. RESULTS: A statistically significant difference was noted in CMAPs amplitudes before and after decompression (P<0.01). In two patients, this variation was so satisficing to determinate the end of procedure, without the need to perform neurolysis. Major correlations between the variation of CMAPs amplitude after surgery and change of DASH and NRS scores at follow-up were found. CONCLUSIONS: Variations of CMAPs amplitude provide real-time information on nerves function and may be helpful in predicting mid- and long-term postoperative outcome regarding pain relief and neurological functions.

Neurovascular Perfusion Study With DynaPBV During Preoperative Balloon Test Occlusion: A Feasibility Study on Aneurysm and Tumor Lesions.

To report feasibility, safety, and technical advantages of flat-detector computed tomography perfusion (FD-CTP) during balloon test occlusion (BTO) angiography studies, 10 patients patients scheduled for BTO were evaluated. Cerebral blood volume maps were extracted from FD-CTP images acquired during the test. The FD-CTP perfusion combined with BTO is feasible and safe in intracranial tumor, and aneurysm cases in which vessel sacrifice should be considered.

Spatio-temporal structure of single neuron subthalamic activity identifies DBS target for anesthetized Tourette syndrome patients.

OBJECTIVE: Deep brain stimulation (DBS) of basal ganglia effectively tackles motor symptoms of movement disorders such as Tourette syndrome (TS). The precise location of target stimulation site determines the range of clinical outcome in DBS patients, and the occurrence of side-effects of DBS. DBS implant procedures currently localize stimulation target relying on a combination of pre-surgical imaging, standardized brain atlases and on-the-spot clinical tests. Here we show that temporal structure of single unit activity in subthalamic nucleus (STN) of patients affected by pure TS can contribute to identify the optimal target location of DBS. APPROACH: Neural activity was recorded at different depths within STN with microelectrodes during DBS implant surgery. Depth specific neural features were extracted and correlated with the optimal depth for tic control. MAIN RESULTS: We describe for the first time temporal spike patterns of single neurons from sensorimotor STN of anesthetized TS patients. A large fraction of units (31.2%) displayed intense bursting in the delta band (<4 Hz). The highest firing irregularity and hence the higher density of bursting units (42%) were found at the optimal spot for tic control. Discharge patterns irregularity and dominant oscillations frequency (but not firing rate) carried significant information on optimal target. SIGNIFICANCE: We found single unit activity features in the STN of TS patients reliably associated to optimal DBS target site for tic control. In future works measures of firing irregularity could be integrated with current target localization methods leading to a more effective and safer DBS for TS patients.

Deep brain stimulation of the posterior limb of the internal capsule in the treatment of central poststroke neuropathic pain of the lower limb: case series with long-term follow-up and literature review.

OBJECTIVE: Central poststroke neuropathic pain is a debilitating syndrome that is often resistant to medical therapies. Surgical measures include motor cortex stimulation and deep brain stimulation (DBS), which have been used to relieve pain. The aim of this study was to retrospectively assess the safety and long-term efficacy of DBS of the posterior limb of the internal capsule for relieving central poststroke neuropathic pain and associated spasticity affecting the lower limb. METHODS: Clinical and surgical data were retrospectively collected and analyzed in all patients who had undergone DBS of the posterior limb of the internal capsule to address central poststroke neuropathic pain refractory to conservative measures. In addition, long-term pain intensity and level of satisfaction gained from stimulation were assessed. Pain was evaluated using the visual analog scale (VAS). Information on gait improvement was obtained from medical records, neurological examination, and interview. RESULTS: Four patients have undergone the procedure since 2001. No mortality or morbidity related to the surgery was recorded. In three patients, stimulation of the posterior limb of the internal capsule resulted in long-term pain relief; in a fourth patient, the procedure failed to produce any long-lasting positive effect. Two patients obtained a reduction in spasticity and improved motor capability. Before surgery, the mean VAS score was 9 (range 8-10). In the immediate postoperative period and within 1 week after the DBS system had been turned on, the mean VAS score was significantly lower at a mean of 3 (range 0-6). After a mean follow-up of 5.88 years, the mean VAS score was still reduced at 5.5 (range 3-8). The mean percentage of long-term pain reduction was 38.13%. CONCLUSIONS: This series suggests that stimulation of the posterior limb of the internal capsule is safe and effective in treating patients with chronic neuropathic pain affecting the lower limb. The procedure may be a more targeted treatment method than motor cortex stimulation or other neuromodulation techniques in the subset of patients whose pain and spasticity are referred to the lower limbs.

Dorsal anterior cingulate cortex (ACC) deep brain stimulation (DBS): a promising surgical option for the treatment of refractory thalamic pain syndrome (TPS).

BACKGROUND: Neuroimaging evidences and previous successful case series of cingulotomy for cancer pain have disclosed the key-role of the dorsal anterior cingulate cortex (ACC) in the generation of the empathic and affective dimension of pain. The aim of this study is to assess the effectiveness and safety of ACC neuromodulation for the treatment of the thalamic pain syndrome (TPS), a chronic neuropathic disease often complicated by severe affective and emotional distress in the long term. METHOD: From January 2015 to April 2017, 5 patients with pure drug-refractory TPS underwent ACC deep brain stimulation (DBS) at our institution. Quantitative assessment of pain and health-related quality of life were performed 1 day before surgery and postoperatively at 6 and 18 months by using the numeric rating scale (NRS), the 36-item short-form health survey (SF-36), and the McGill pain and the EuroQol5-domain questionnaires. RESULTS: Mean age at surgery was 56.2 years (range, 47-66). NRS score improved by 37.9% at 6 months (range, - 22.2 to - 80%) and by 35% at 18 months (range, - 11.1 to - 80%). At the last follow-up, one patient reported a relevant pain reduction (NRS 2), only complaining of mild pain poorly interfering with activities of daily living. Concomitant improvements in the McGill and EuroQol5-domain pain questionnaires, SF-36 total and sub-item scores were also noticed at each follow-up. No surgical or stimulation-related complications occurred during the study period. CONCLUSIONS: ACC DBS may be a safe and promising surgical option to alleviate discomfort and improve the overall quality of life in a patient affected by drug-resistant TPS. Further prospective, larger, and randomized studies are needed to validate these findings.

An unusual surgical indication for cerebral tuberculosis: status dystonicus. Case report.

Actual indications for surgery in tuberculosis are limited to obtaining a diagnosis, acquiring tissue for culture studies, treating hydrocephalus, aspiring a brain abscess, and reducing intracranial pressure in patients with multiple tuberculomas. Tuberculosis-related movement disorders are usually treated pharmacologically. We report on a child affected by post-tubercular generalized dystonia, who progressed to status dystonicus (SD) and underwent stereotactic bilateral pallidotomy. After surgery, SD resolved, and drugs were rapidly tapered. The successful reversal of SD and the motor improvement observed in our patient demonstrate the safety, feasibility, and clinical efficacy of pallidotomy in post-tuberculous-meningoencephalitis dystonia and SD.

Multimodal Approach for Radical Excision of Focal Cortical Dysplasia by Combining Advanced Magnetic Resonance Imaging Data to Intraoperative Ultrasound, Electrocorticography, and Cortical Stimulation: A Preliminary Experience.

BACKGROUND AND OBJECTIVE: Type II focal cortical dysplasia is the most common malformation of cortical development associated with drug resistant epilepsy and susceptible to surgical resection. Although, at present, advanced imaging modalities are capable of detecting most cortical disorders, it is still a challenge for the surgeon to visualize them intraoperatively. The lack of direct identification between normal brain and subtle dysplastic tissue may explain the poor results in terms of being seizure-free versus other forms of epilepsy. The aim of this study is to compare magnetic resonance imaging (MRI) and intraoperative ultrasound-guided neuronavigation, along with cortical stimulation and acute electrocorticography, as a multimodal surgical approach to cortical dysplasia's tailored resection. METHODS: Six consecutive patients with type II cortical dysplasia underwent epilepsy surgery by means of MRI/intraoperative ultrasound-guided neuronavigation. Intraoperative cortical stimulation of sensory/motor cortex was performed to localize cortical eloquent areas. Acute electrocorticography was used to identify epileptogenic tissue. These findings were correlated to real-time ultrasound imaging to establish the extent of the resection. RESULTS: Intraoperative ultrasound depicted cortical dysplasias at a higher resolution and accuracy than MRI. Therefore it maximized the extent of the resection. Both postoperative MRIs and pathology documented the extent of the resection in all patients. Seizure-freedom was achieved in 5 cases (Engel class IA), and in 1 patient it was classified as Engel class IB. No postoperative neurological deficits were observed. CONCLUSIONS: These results strongly suggest feasibility of ultrasound-guided resection of focal cortical dysplasia. Providing high resolution and accuracy, it allows an easy, real-time discrimination between normal and dysplastic brain.

Ultrasound guided mini-invasive tailored approach and intraoperative neurophysiological monitoring: a synergistic strategy for the removal of tumors near the motor cortex. A preliminary experience.

BACKGROUND: The aim of this paper was to evaluate the synergic strategy comprising intraoperative neurophysiological monitoring and ultrasound sonography in terms of clinical motor scores and extent of resection. METHODS: Patients harboring tumors in close relationship with the motor cortex were operated on with image-guided mini-invasive approach and multimodal neurophysiological monitoring. The peculiarity is the partial exposure of the motor cortex and the limited electrophysiological mapping used to search for negative spots. Multimodal neurophysiological monitoring comprised the electrocortical stimulation, somatosensory evoked potentials, motor evoked potentials and subcortical stimulation. Ultrasound sonography guided the tumor removal. The post-op clinical motor scores and the extent of resection were assessed. RESULTS: Twelve patients were operated on with the combined approach and were further analyzed. Six had high grade gliomas, 1 anaplastic astrocytoma, 1 oligodendroglioma, 1 pilocytic astrocytoma and three had metastasis. One out of 12 had a worsening of the motor scores at the last follow-up. The mean extent of resection was 90% ranging from 60% to 100%, but in 9 out of 12 patients, it reached or exceeded 90%. CONCLUSIONS: The synergic strategy comprising intraoperative multimodal neurophysiological monitoring and the ultrasound sonography is feasible in all surgeries. Data are promising in terms of both clinical motor scores and extent of resection. This strategy represents an alternative approach to the treatment of supratentorial tumors, although further studies are necessary to confirm the long-term efficacy of this procedure.

Motor Evoked Potentials and Bispectral Index-Guided Anaesthesia in Image-Guided Mini-Invasive Neurosurgery of Supratentorial Tumors Nearby the Cortico-Spinal Tract.

AIM: To describe and evaluate the anaesthesiological regimen used in neurophysiologically monitored image-guided mini-invasive neurosurgery. MATERIAL AND METHODS: Twenty-four patients underwent elective surgery under general anaesthesia that was administered through Target Controlled Infusion (TCI) for effect-site concentration (Ce) of Propofol and Remifentanil, targeting the Bispectral Index (BIS) in the 40-60 intervals. The stimulating intensity of transcranial motor evoked potentials (tMEP), BIS, Propofol and Remifentanil Ce were collected at MEPs threshold (T) definition (respectively BIS@T, CeProp@T and CeRemi@T). Intraoperative seizure, explicit recall for intraoperative awareness and clinical motor status were assessed. RESULTS: CeProp@T and CeRemi@T ranged respectively between 1.5-2.2 µg/ml (Median 1.6 µg/ml) and 3.5-18 ng/ml (Median 8 ng/ml) that were effective in keeping the BIS@T between 40 and 60 in all surgeries. tMEP thresholds ranged between 45 and 120 mA. There was no correlation between CeProp@T, CeRemi@T and tMEP, as well as between BIS@T and respectively tMEP, CeProp@T, CeRemi@T. None of patients had induced electrical seizure or explicit recalls. Motor scores were equal to preoperative values in 22/24 patients. CONCLUSION: BIS-guided general anaesthesia within a 40-60 interval, with low Ce of Propofol (≤2 µ/ml) and high analgesic regime allow reliable tMEP measurements, avoiding postoperative neurological impairment and major adverse outcomes, such as seizure and awareness.

Surgical "Fat Patch" Improves Secondary Intracranial Hypotension Orthostatic Headache Associated with Lumbosacral Dural Ectasia.

BACKGROUND: Secondary intracranial hypotension is a clinical syndrome associated with reduction of cerebrospinal fluid volume and dural continuity violation. The main symptoms are orthostatic headache associated with nausea, vomiting, diplopia, dizziness, and tinnitus. The treatment is usually nonspecific. CASE DESCRIPTION: A 37-year-old woman developed secondary intracranial hypotension caused by lumbosacral iatrogenic dural ectasia following detethering surgery. An orthostatic headache was the mainstay of her clinical picture, and it was confirmed by intracranial pressure monitoring. Conservative treatment including spinal blood patch improved symptoms for a limited amount of time (<1 month). Altered compliance of the dural spinal sac was suspected. Therefore thecal sac remodeling by placing autologous fat at the level of the dural ectasia was performed, improving the symptoms for 2 years. CONCLUSION: Volumetric reduction of the epidural space may be considered as a valuable therapeutic option in case of intracranial hypotension that is unresponsive to medical treatments and spinal blood patch, as well as when an altered compliance of the dural sac is hypothesized.

Fluorescein-Guided Resection of Intramedullary Spinal Cord Tumors: Results from a Preliminary, Multicentric, Retrospective Study.

BACKGROUND: Intramedullary spinal cord tumors (IMSCTs) are rare, heterogenous lesions that are usually enhanced on preoperative magnetic resonance imaging (MRI) because of a damaged blood-brain barrier. Sodium fluorescein is a dye that accumulates in areas of the central nervous system with a damaged BBB. Given the pattern of MRI contrast enhancement of the majority of IMSCTs, the use of this fluorescent tracer could improve tumor visualization and quality of resection. In this article, we present the first experience with the application of fluorescein-guided technique for surgical removal of IMSCTs. METHODS: Eleven patients (6 men, 5 women; mean age, 50.1 years), harboring 5 ependymomas, 3 hemangioblastomas, 1 astrocytoma, 1 pilocytic astrocytoma, and 1 glioneuronal tumor forming rosettes were included. Sodium fluorescein (5 mg/kg) was injected immediately after patient intubation. Tumors were removed with microsurgical technique and standard neurophysiological monitoring, under YELLOW 560 filter (Pentero 900) visualization. Surgical reports were reviewed regarding usefulness and grade of fluorescein staining. Postoperative MRI was performed within 72 hours after surgery, and postoperative clinical outcome was registered. RESULTS: No adverse events were registered. Fluorescent staining was reported in 9 of 11 cases (82%), all of them enhancing on preoperative MRI (100% of ependymomas, 100% of pilocytic astrocytomas, 100% of hemangioblastomas). No fluorescence was reported in 1 astrocytoma and 1 glioneuronal tumor-forming rosette. Intraoperative fluorescence was considered helpful for tumor resection in 9 of 11 cases (82%). Gross total resection was obtained in 8 of 11 cases (72.7%). CONCLUSIONS: Our results suggest that fluorescein-guided surgery is a safe and effective technique that can be used during the surgical resection of IMSCTs presenting with contrast-enhancement on preoperative MRI.

The lateral infratrigeminal transpontine window to deep pontine lesions.

OBJECT: Surgery of brainstem lesions is increasingly performed despite the fact that surgical indications and techniques continue to be debated. The deep pons, in particular, continues to be a critical area in which the specific risks related to different surgical strategies continue to be examined. With the intention of bringing new knowledge into this important arena, the authors systematically examined the results of brainstem surgeries that have been performed through the lateral infratrigeminal transpontine window. METHODS: Between 1990 and 2013, 29 consecutive patients underwent surgery through this window for either biopsy sampling or for removal of a deep pontine lesion. All of this work was performed at the Department of Neurosurgery of the Istituto Nazionale Neurologico "Carlo Besta", in Milan, Italy. A retrospective analysis of the findings was conducted with the intention of bringing further clarity to this important surgical strategy. RESULTS: The lateral infratrigeminal transpontine window was exposed through 4 different approaches: 1) classic retrosigmoid (15 cases), 2) minimally invasive keyhole retrosigmoid (10 cases), 3) translabyrinthine (1 case), and 4) combined petrosal (3 cases). No deaths occurred during the entire clinical study. The surgical complications that were observed included hydrocephalus (2 cases) and CSF leakage (1 case). In 6 (20.7%) of 29 patients the authors encountered new neurological deficits during the immediate postoperative period. All 6 of these patients had undergone lesion removal. In only 2 of these 6 patients were permanent sequelae observed at 3 months follow-up. These findings show that 93% of the patients studied did not report any permanent worsening of their neurological condition after this surgical intervention. CONCLUSIONS: This retrospective study supports the idea that the lateral infratrigeminal transpontine window is both a low-risk and safe corridor for either biopsy sampling or for removal of deep pontine lesions.

Immediate disappearance of hemifacial spasm after partial removal of ponto-medullary junction anaplastic astrocytoma: case report.

Hemifacial spasm (HFS) is generally caused by a neurovascular conflict (NC) at the root exit zone (REZ) of the facial nerve at the brainstem. Although a direct compression to the seventh cranial nerve (CN) by the anterior inferior cerebellar artery (AICA) is generally the most frequent cause, secondary HFS may be related to other pathological conditions. HFS due to an intracranial mass lesion is exceptionally rare and it has been reported in very few cases. The online database was searched for English-language articles reporting cases of HFS due to brainstem mass lesions and the possible pathophysiological mechanisms involved in its genesis. A 47-year-old man affected by an anaplastic astrocytoma of the brainstem at the level of the ponto-medullary junction developed right HFS. He underwent a subtotal surgical removal of the tumor with complete resolution of the HFS. This is the ninth reported case of HFS caused by an intrinsic brainstem tumor. The exceptional rarity of the relationship between intra-axial tumors and peripheral HFS was analyzed.

Fluorescein-guided surgery for malignant gliomas: a review.

Fluorescein is widely used as a fluorescent tracer for many applications. Its capacity to accumulate in cerebral areas where there has been blood-brain barrier damage makes it particularly suitable as a dye for the intraoperative visualization of malignant gliomas (MGs). In this report, we describe the results of a comprehensive review on the use of fluorescein in the surgical treatment of MGs. A comprehensive literature search and review for English-written articles concerning the use of fluorescein in the resection of MGs has been conducted. The search was executed through a PubMed literature search using the following keywords: malignant gliomas, glioblastomas, high-grade gliomas, YELLOW 560, total removal, dedicated filter, neurosurgery, brain tumors, intracranial tumors, and confocal microscopy. The literature search resulted in the retrieval of 412 evidence-based articles. Of these, 17 were found to be strictly related to the resection of MG with the aid of fluorescein. In addition to these 17, we have included 2 articles derived from a personal database of the corresponding author (FA). The analysis of the articles reviewed revealed three major applications of fluorescein during surgery for MGs that was documented: Fluorescein-guided resection of MGs with white-light illumination, fluorescein-guided resection of MGs with a surgical microscope equipped with a dedicated filter for fluorescein, and confocal microscopy for intraoperative histopathological analysis on MGs. The systemic review conducted on the use of fluorescein in MGs explored the applications and the different modalities in which fluorescein has been used. The data we have gathered indicates that fluorescein-guided surgery is a safe, effective, and convenient technique to achieve a high rate of total removal in MGs. Further prospective comparative trials, however, are still necessary to prove the impact of fluorescein-guided surgery on both progression-free survival and overall survival.

Long-term outcome after limited cortical resections in two cases of adult-onset Rasmussen encephalitis.

Rasmussen encephalitis (RE) is a progressive inflammatory disorder characterized by brain hemiatrophy, unilateral focal deficits, and drug-refractory focal epilepsy. Epilepsia partialis continua (EPC) is a hallmark of the disease. Several immunomodulatory treatments may slow but not halt the disease progression. The treatment of choice still relies on surgical hemispheric disconnection, which is burdened by heavy neurologic morbidity. More limited cortical resections, although more tolerable, are usually considered to be, at best, only transiently effective in RE. Hemispheric disconnections may be not feasible when neurologic functions are preserved and the dominant hemisphere is affected. Adult patients with a milder RE course that preserves neurologic function for a long period are particularly at risk of developing severe deficits after surgery. In this study we present the histories of two patients with adult-onset RE who have undergone selective cortical resections to control EPC, avoiding, at the same time, the severe postsurgical deficits that may be induced by hemispheric disconnective surgery. The good result obtained on EPC has been stable over a prolonged period; however, this result was not paralleled by the stop of neurologic progression in one of the two cases. A PowerPoint slide summarizing this article is available for download in the Supporting Information section http://dx.doi.org/10.1111/epi.12596/supinfo.

Is fluorescein-guided technique able to help in resection of high-grade gliomas?

OBJECT: Fluorescein, a dye that is widely used as a fluorescent tracer, accumulates in cerebral areas where the blood-brain barrier is damaged. This quality makes it an ideal dye for the intraoperative visualization of high-grade gliomas (HGGs). The authors report their experience with a new fluorescein-guided technique for the resection of HGGs using a dedicated filter on the surgical microscope. METHODS: The authors initiated a prospective Phase II trial (FLUOGLIO) in September 2011 with the objective of evaluating the safety of fluorescein-guided surgery for HGGs and obtaining preliminary evidence regarding its efficacy for this purpose. To be eligible for participation in the study, a patient had to have suspected HGG amenable to complete resection of the contrast-enhancing area. The present report is based on the analysis of the short- and long-term results in 20 consecutive patients with HGGs (age range 45-74 years), enrolled in the study since September 2011. In all cases fluorescein (5-10 mg/kg) was injected intravenously after intubation. Tumor resection was performed with microsurgical technique and fluorescence visualization by means of BLUE 400 or YELLOW 560 filters on a Pentero microscope. RESULTS: The median preoperative tumor volume was 30.3 cm(3) (range 2.4-87.8 cm(3)). There were no adverse reactions related to fluorescein administration. Complete removal of contrast-enhanced tumor was achieved in 80% of the patients. The median duration of follow-up was 10 months. The 6-months progression-free survival rate was 71.4% and the median survival was 11 months. CONCLUSIONS: Analysis of these 20 cases suggested that fluorescein-guided technique with a dedicated filter on the surgical microscope is safe and allows a high rate of complete resection of contrast-enhanced tumor as determined on early postoperative MRI. Clinical trial registration no.: 2011-002527-18 (EudraCT).

Occult spinal dysraphism: lessons learned by retrospective analysis of 149 surgical cases about natural history, surgical indications, urodynamic testing, and intraoperative neurophysiological monitoring.

PURPOSE: Prophylactic surgery is indicated for lipoma of the filum, while it is still debated for the conus lipomas and more complex tethering malformations of the cord. METHODS: We retrospectively reviewed the preoperative and postoperative clinical histories and long-term outcomes of 149 operated patients (33 adults, 116 children). Intraoperative neurophysiological monitoring (NPM) was utilized since 1998. Their malformative lesions were reclassified following recent Pang's embryological criteria for surgical complexity. In nine cases, the spinal tethering malformation was associated with an anorectal malformation (ARM) and in nine with a Chiari I malformation (CM1). RESULTS: One hundred nineteen (80 %) patients were symptomatic at the time of surgery, 66 (44 %) having presented with progressive preoperative deterioration. Postoperative surgery-related deterioration was observed in 6 % of the cases operated on under the intraoperative NPM control. Surgery did not improve any deficit, especially of sphincter functions, independently from the type of associated malformation (ARM, CM1). Urodynamic testing was a reliable predictor both in the preoperative and in the follow-up period of subsequent neurological deterioration. In the long-term follow-up, an increasing percentage of retethering was observed, especially concerning complex cases submitted to partial excision. The surgical risk increased with repeated operations. CONCLUSIONS: This study demonstrates that the rate of the natural deterioration associated with a conservative approach is higher than in patients operated on prophylactically, if the operation is performed by a team with a special expertise. However, the first surgical procedure should be aimed at detethering the conus completely, with the aid of intraoperative NPM; even in expert hands, it is associated with a high risk of clinical deterioration. Based on these results, we are increasing the percentage of children to whom surgery is offered when still asymptomatic as well as the degree of the lipoma excision to prevent retethering. However, in cases of rethetering and subjects presenting in adult age, we suggest to consider for surgery only those symptomatic. Urodynamic testing and magnetic resonance imaging in prone position were, in our experience, the best tools for screening those patients at risk of symptomatic retethering.

Morphological and chemical analysis of a deep brain stimulation electrode explanted from a dystonic patient.

Deep brain stimulation is an effective treatment for different types of dystonia; nevertheless dystonic movements could provoke hardware-related complications, including fractures or electrodes displacement. This study focuses on a morphological and structural analysis of a malfunctioning electrode removed from a dystonic patient. In this case, high impedance values and worsening of symptoms were observed. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) were performed on the explanted electrode. The qualitative and quantitative data collected from the damaged electrode were compared with a new electrode, used as a control. The SEM analysis of the damaged electrode revealed fissurations and crack-like forms of the outer jacket tubing, degeneration of the internal core and wires stretching. The EDX analysis permitted to appreciate an increase of chemical elements, especially sodium, suggesting an alteration of the electrode-brain interface. This study shows the qualitative and quantitative alterations of a malfunctioning electrode and, to reduce the rate of hardware-related complications, it suggests the development of more reliable polymers.

Practical assessment of preoperative functional mapping techniques: navigated transcranial magnetic stimulation and functional magnetic resonance imaging.

Preoperative brain mapping is vital to improve the outcome of patients with tumors located in eloquent areas. While functional magnetic resonance imaging (fMRI) remains the most commonly used preoperative mapping technique, navigated transcranial magnetic stimulation (nTMS) has recently been proposed as a new preoperative method for the clinical and surgical management of such patients. This study aims at evaluating the impact of nTMS as a routine examination and its ultimate contribution to patient outcome. We performed a preliminary prospective study on eight patients harboring a cerebral lesion in eloquent motor areas. Each patient underwent preoperative cortical brain mapping via both fMRI and nTMS; then, we assessed the reliability of both methods by comparing them with intraoperative mapping by direct cortical stimulation (DCS). This study suggests that nTMS was more accurate than fMRI in detecting the true cortical motor area when compared with DCS data, with a mean of deviation ± confidence interval (CI) of 8.47 ± 4.6 mm between nTMS and DCS and of 12.9 ± 5.7 mm between fMRI and DCS (p < 0.05). The results indicated that within the limits of our statistical sample, nTMS was found to be a useful, reliable, and non-invasive option for preoperative planning as well as for the identification of the motor strip; in addition, it usually has short processing times and is very well tolerated by patients, thereby increasing their compliance and possibly improving surgical outcome.