Faculty Bibliography

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.

Background/UNASSIGNED:Medical residents must sustain acute sleep deprivation, which can lead to nonfatal and fatal consequences in hospitals due to cognitive decline. Anodal transcranial direct current stimulation (a-tDCS) is a safe noninvasive neuromodulation technique that can induce depolarization of neurons. Previous studies in pilots have shown benefits against fatigue increasing wakefulness and cognitive performance. However, the effects of a-tDCS on cognition in acute sleep deprived healthcare workers remains unknown. Purpose/UNASSIGNED:To evaluate cognitive changes in sleep deprived medical residents after one session of a-tDCS. Methods/UNASSIGNED:Open clinical test-re-test study including 13 medical residents with acute sleep deprivation. Subjects received 1 session of bifrontal a-tDCS (2mAx20min), anodal over the left dorsolateral prefrontal region. Pre-and-post treatment subjects were tested with Beck anxiety inventory, Beck depression and HVLT tests, Rey´s and Taylor´s figures, Trail Making A/B, Stroop, Aleatory Digit retention test (WAIS), Digits and symbols and MoCA tests. Post-intervention was added the Executive functions and Frontal Lobes Neuropsychological Battery (BANFE2) test and changing the Taylor figure for Reyfigure. Results/UNASSIGNED:Twelve medical residents were analyzed; 8 men and 4 women, 29.5 (+/-2.2) years mean age. All had a mean of 21.6 (+/-1.3) hours of sleep deprivation. There were no serious adverse events. We found statistically significant difference in Rey´s/Taylor´s figures (p=0.002), Trail Making Test (p=0.005), WAIS IV symbols (p=0.003), Word Stroop (p=0.021). BANFE-2 showed that the main affected area was the orbito-medial prefrontal region. Conclusion/UNASSIGNED:a-tDCS appears safe and improves working memory, attention, response time and distractors elimination in acute sleep deprived medical residents.

INTRODUCTION/BACKGROUND:Intraoperative neurophysiological monitoring (IONM) is widely used to prevent nervous system injury during surgeries in elderly patients. However, there are no studies that describe the characteristics and changes in neurophysiological tests during the IONM of patients aged 60 years and older. The study aims to describe and compare IONM changes during surgeries in adult patients aged 18 to 59 years with those aged 60 years and older. METHODS:We performed a comparative retrospective study of patients aged 18 to 59 years versus those 60 aged years and older who underwent IONM during 2013 to 2018 in Mexico City. Sociodemographic characteristics were recorded and compared. Intraoperative neurophysiological monitoring techniques, their changes, and surgical procedures for both groups were analyzed and compared using descriptive statistics, Mann-Whitney U, Fisher, and χ tests. The sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS:In total, 195 patients were analyzed: 104 patients, 68.63 ± 6.54 years old (elderly group) and 91 patients, 42.3 ± 10.5 years old (younger group). No differences were found in the rates of signal change during IONM between the group of elderly patients and the younger group. The sensitivity, specificity, and positive and negative predictive values were 80%, 99%, 80%, and 99%, respectively. CONCLUSIONS:Elderly patients have a similar rate of changes in IONM signals compared with younger patients during heterogeneous surgeries guided by IONM.

OBJECTIVES/OBJECTIVE:The aim of this study is to analyze changes in the Social Determinants of Health (SDH) in patients undergoing epilepsy surgery in Mexico. MATERIALS AND METHODS/METHODS:We retrospectively analyzed 102 adult patients who underwent brain resection for focal epilepsy (2002-2014) with at least 4 years of follow-up; described clinical variables (age, race, sex, age of onset of epilepsy, age at the time of surgery, type of surgery, side of surgery) and sociodemographic variables including education, income, race/ethnicity, occupation, and marital status. STATISTICAL ANALYSIS/METHODS:Descriptive and inferential statistics were used. RESULTS:54.9% (56) of the participants were women, with a mean age of 38.2 (±9.6) years at the time of the survey. The average and mean duration of drug-resistant epilepsy before surgery after diagnosis was 19.6 (±9.3) years; 77.9% (77) had temporal lobe surgeries and 24.5% (25) had extra-temporal lobe surgeries; 80.4% (82) and 19.6% (20) of patients were classified as Engel I and Engel II, respectively, with at least 4 years of postoperative follow-up. Education level (26.9%, p=<0.001), employment rate (4.9%, p= <0.001), and income (9.8%, p = 0.024) increased after surgery; 20.5% of patients were married after surgery. CONCLUSIONS:Following focal resective epilepsy surgery there was a significant increase in the education level, financial income and employment at 4 years' postoperative follow-up.

The montages in clinical EEG recordings in neonates, infants, and children follow some basic principles of adolescent or adult EEG recordings; however, special considerations are needed to obtain optimal diagnostic yield in pediatric patients. The aim of this review is to summarize the pediatric montages recommended in clinical practice in the standard clinical neurophysiology laboratory and in special situations.

BACKGROUND:Electroconvulsive therapy (ECT), Vagal Nerve Stimulation (VNS), Transcranial Magnetic Stimulation (TMS) and Deep Brain Stimulation (DBS) are neuromodulation therapies that have been used to treat Status Epilepticus (SE). OBJECTIVE:Review the literature about the efficacy and safety of neuromodulation therapies in SE in humans. METHODS:We searched studies in PubMed, Scopus, Google Scholar and Science Direct (inception to June 2018). 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, Oxford and GRADE scales, and Murad et al., 2018 methodological quality and synthesis of case series and case reports. RESULTS:We analyzed 27 articles (45 patients) with 4 different neuromodulation therapies. In ECT we found 80% rate of disruption of SE and 5% of adverse events was reported. Using iVNS 15/16 (93.7%) patients resolved the SE. All patients who underwent TMS and DBS aborted SE, however, 50% of patients with DBS had severe adverse events. CONCLUSIONS:Case series and case reports suggest that neuromodulation therapies can abort SE in 80-100% of patients (Oxford scale and GRADE were level 4 and D) with a wide range of adverse effects, which claims for prospective studies on the relationship be-tween efficacy and safety.

BACKGROUND:Super refractory epilepticus status (SRSE) is a life-threatening neurologic emergency defined as 'status epilepticus (SE) that continues 24 hours or more after the onset of anaesthesia, including those cases in which the SE recurs on the reduction or withdrawal of anaesthesia', which occur in 10-15% of SE patients and rarely has been resolved surgically. METHODS:A 20-year-old man with SRSE and a long history of left parieto-occipital oligoastrocytoma was admitted for convulsive SE that become SRSE and underwent lesionectomy guided by electrocorticography and neuro-navigation for local tumor recurrence. Histopathological diagnosis was oligoastrocytoma. RESULTS:SRSE was aborted and the patient recovery fully without any functional deficits. CONCLUSIONS:The lesionectomy guided by electrocorticography and neuro- navigation should be considered as a treatment option for patients with SRSE.