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OBJECTIVE Sylvian fissure (SF) arteriovenous malformations (AVMs) are among the most challenging vascular lesions amenable to neurosurgical treatment and account for 10% of all locations. As radiosurgery and endovascular techniques are increasingly involved in multimodal management protocols, the role of microsurgery needs to be reassessed as a stand-alone technique. The aim of this study was to show that total excision can be achieved with reasonable levels of morbidity and mortality in a real-world setting from a specialized high-volume center. METHODS Forty-three patients with SF AVMs were identified from a series of 577 AVM patients treated microsurgically over a 22-year period. The mean patient age was 33.07 years (range 15–60 years), and there were 22 male and 21 female patients. The mode of presentation was headache in 51.2%, hemorrhage in 34.9%, seizures in 30.2%, and steal phenomenon in 9.3%. The authors analyzed the anatomical basis and angiographic characteristics of such lesions. RESULTS In the preoperative period, 83.7% of the patients had a modified Rankin Scale (mRS) score of 0–2, and 16.3% had an mRS score of 3–5. After a 12-month follow-up, 95.3% of patients had an mRS score of 0–2, and 4.7% had a score of 3–6. The difference between pre- and postoperative scores was not statistically significant. SF AVMs have several particular features: 1) They produce angiographic steal of the anterior cerebral artery. 2) The nidus is fed by only one of the main trunks of the middle cerebral artery (MCA). 3) Participation of deep perforators is uncommon. 4) They have two or more early draining veins showing their fistulous nature. 5) Preoperative embolization and radiosurgery have a low rate of permanent cure. CONCLUSIONS These AVMs represent a surgical challenge due to their proximity to critical structures such as the MCA, insula, internal capsule, and speech and memory functions in the dominant hemisphere. Essential key points are the wide opening of the SF and proper differentiation between feeders and normal vessels. Although this location can seem daunting, SF AVMs carry no additional surgical risk if adequately managed.

Transcranial Alternating Current Stimulation (tACS) is a promising noninvasive electrical stimulation therapy for neuropsychiatric diseases. Invasive neuromodulation using alternating current has been efficacious for drug-resistant epilepsy, but it is associated with surgical and medical complications. We aimed to explore the safeness and effectivity on seizure frequency reduction of two tACS protocols against placebo in patients with multifocal refractory epilepsy. This was a randomized, double-blinded, placebo-controlled clinical trial with 3-arm parallel-group (placebo, 30 min/2 mA daily sessions for 3 days [tACS-30], and 60 min/2 mA weekday sessions [tACS-60]). The main outcome was considered a change in reducing seizure frequency at 2 months after the intervention. Secondary outcomes were the apparition of any adverse effects during follow-up. At the second month, we observed a nonsignificant reduction in the seizure frequency in the placebo (7.3 ± 40.4%, p 0.05) and the tACS-60 (26 ± 37.7%, p 0.05). While the tACS-30 group showed a nonsignificant increase in seizure frequency (63.6 ± 155.3%, p 0.05). No changes were statistically different from the placebo group. Otherwise, participants experienced only minor adverse events - the most common being an initial local transient tingling sensation (21%). This pilot study of tACS raises no severe safety issues, but provides negligible evidence for efficacy using this brief treatment protocol. Therefore, more studies are warranted testing different parameters to further verify the safety and effectivity of tACS in multifocal epilepsy.

Surgical resection guided by intraoperative electrocorticography (iECoG) has been in clinical use for many decades. The use of the bispectral index (BIS) for monitoring depth of anesthesia during different types of surgery, including epilepsy surgery, is increasing nowadays. The BIS is an EEG-derived variable indicating cortical electrical activity. However, the correlation between the BIS score and the iECoG score, with the purpose of optimizing the quality and time of the iECoG recordings in epilepsy surgery is unknown. The goal of this study was to evaluate the correlation between BIS values and iECoG parameters during the epilepsy surgery under anesthesia with propofol and fentanyl. This is a prospective study that included patients with epilepsy who underwent epilepsy surgery guided by BIS and iECoG (September 2008 to October 2013). Clinical, physiological, and sociodemographic characteristics are shown. We correlated the iECoG parameters (presence of burst suppressions [BS], suppression time [seconds], background frequency [Hz], and type of iECoG score by Mathern et al) with BIS values. We included 28 patients, 15/28 (53.5%) female, general mean age of 30.5 years (range 13-56 years). Patients underwent epilepsy surgery: 22/28 (79%) temporal and 6/28 (21%) extratemporal. We found a nonlinear polynomial cubic relationship between the mentioned variables noting that a BIS range of 40 to 60 gave the following results: iECoG BS periods 20-Hz background frequencies. No BS were observed with a BIS > 60. In conclusion BIS values and iECoG parameters during the epilepsy surgery under anesthesia with propofol and fentanyl have a nonlinear correlation. BS patterns were not found with a BIS > 60. These findings show that BIS is a nonlinear multidimensional measure, which possesses high variability with the iECoG parameters. BS patterns are not found with BIS > 60.

De las diversas complicaciones de la meningoencefalitis infecciosa, el síndrome de Guillain-Barré es raro. Presentamos el caso de una mujer de 37 años de edad, quien inicio con meningoencefalitis infecciosa, a los 9 días se observó empeoramiento de la fuerza y sensibilidad de las cuatro extremidades. Con sospecha clínica y electromiografía se diagnosticó polineuropatía desmielinizante secundariamente axonal sensitiva motora de las cuatro extremidades. No se aisló un patógeno específico. El manejo integral e inmunomodulador (IgG IV 0.4g/kg/dx5d) estuvo basado en los principios establecidos para las dos situaciones neurológicas observadas en la paciente. La paciente se recuperó totalmente a los 6 meses.

Background: Transcranial direct current stimulation (tDCS) is an emerging non-invasive neuromodulation therapy in epilepsy with conflicting results in terms of efficacy and safety. Objective: Review the literature about the efficacy and safety of tDCS in epilepsy in humans and animals. Methods: We searched studies in PubMed, MedLine, Scopus, Web of Science and Google Scholar (January 1969 to October 2013) using the keywords ‘transcranial direct current stimulation’ or ‘tDCS’ or ‘brain polarization’ or ‘galvanic stimulation’ and ‘epilepsy’ in animals and humans. Original articles that reported tDCS safety and efficacy in epileptic animals or humans were included. Four review authors independently selected the studies, extracted data and assessed the methodological quality of the studies using the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions, PRISMA guidelines and Jadad Scale. A meta-analysis was not possible due to methodological, clinical and statistical heterogeneity of included studies. Results: We analyzed 9 articles with different methodologies (3 animals/6 humans) with a total of 174 stimulated individuals; 109 animals and 65 humans. In vivo and in vitro animal studies showed that direct current stimulation can successfully induce suppression of epileptiform activity without neurological injury and 4/6 (67%) clinical studies showed an effective decrease in epileptic seizures and 5/6 (83%) reduction of inter-ictal epileptiform activity. All patients tolerated tDCS well. Conclusions: tDCS trials have demonstrated preliminary safety and efficacy in animals and patients with epilepsy. Further larger studies are needed to define the best stimulation protocols and long-term follow-up.

a Neurophysiology Department, National Institute of Neurology and Neurosurgery “Manuel Velasco Suarez”, Av. Insurgentes Sur 3877, Col. La Fama, Tlalpan, Mexico D.F. 14269, Mexico b Laboratory of Neuromodulation, Department of Physical Medicine & Rehabilitation, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, 300 1st Ave, Charlestown, MA 02129, USA c Neurosurgery Department, National Institute of Neurology and Neurosurgery “Manuel Velasco Suarez”, Av. Insurgentes Sur 3877, Col. La Fama, Tlalpan, Mexico D.F. 14269, Mexico d Comprehensive Epilepsy Center of Long Island, St. Charles Hospital, 200 Belle Terre Rd., Port Jefferson, NY 11777, USA

Background: Transcranial direct current stimulation (tDCS) has been evaluated in medication refractory epilepsy patients. The results have been inconclusive and protocols have varied between studies. Objective: To evaluate the safety and efficacy of two protocols of tDCS in adult patients with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS). Methods: This is a randomized placebo-controlled, double-blinded clinical trial, with 3 arms, 3 sessions, 5 sessions and placebo stimulation. Frequency of seizures (SZs), interictal epileptiform discharges (IEDs) and adverse effects (AEs) were registered before and after treatment, and at 30 and 60 days follow-up. Descriptive statistics, k-related samples, Friedman's test, and relative risk (RR) estimation were used for analysis. Results: We included twenty-eight subjects (3d n = 12, 5d n = 8, placebo n = 8), 16/28 (57%) men, age 37.8(±10.9) years old. There was a significant reduction of the frequency of SZs at one (p = 0.001) and two (p = 0.0001) months following cathodal tDCS compared to baseline in the 3 arms (p = 0.0001). The mean reduction of SZ frequency at two months in both active groups was significantly higher than placebo (−48% vs. −6.25%, p

Aim. To describe the general aspects of cavernomas and epilepsy and review the available literature on the utility of electrocorticography (ECoG) in cerebral cavernoma surgery. Methods. We searched studies in PubMed, MedLine, Scopus, Web of Science, and Google Scholar (from January 1969 to December 2013) using the keywords “electrocorticography” or “ECoG” or “prognosis” or “outcome” and “cavernomas”. Original articles that reported utility of ECoG in epilepsy surgery were included. Four review authors independently selected the studies, extracted data, and assessed the methodological quality of the studies using the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions, PRISMA guidelines, and Jadad Scale. A meta-analysis was not possible due to methodological, clinical, and statistical heterogeneity of included studies. We analysed six articles with a total of 219 patients. Results. The most common surgical approach was lesionectomy using ECoG in the temporal lobe with Engel I outcome range from 72.7 to 100%. Conclusions. Small controlled studies suggest that ECoG-guided resection offers the best functional results in seizure control for subjects undergoing cavernoma surgery, especially in the temporal lobe.