Narong Auvichayapat

Association between HLA-B*1502 and carbamazepine-induced severe cutaneous adverse drug reactions in a Thai population

Carbamazepine (CBZ) has been reported as the most common culprit drug for Stevens‐Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in several Asian countries including Thailand. A strong association between HLA‐B*1502 and CBZ‐induced SJS/TEN has been reported in Han Chinese but not in Caucasian and Japanese populations. A case–control study was conducted to determine whether HLA‐B*1502 is a valid pharmacogenetic test for SJS/TEN caused by CBZ in a Thai population. Among 42 CBZ‐induced patients with SJS/TEN, 37 (88.10%) patients carried the HLA‐B*1502 while only 5 (11.90%) of the CBZ‐tolerant controls had this allele. The risk of CBZ‐induced SJS/TEN was significantly higher in the patients with HLA‐B*1502, with an odds ratio (OR) of 54.76 [95% confidence interval (CI) 14.62–205.13, p = 2.89 × 10−12]. The sensitivity and specificity of HLA‐B*1502 for prediction of CBZ‐induced SJS/TEN were 88.10%. By assuming a 0.27% as a prevalence rate of CBZ‐induced SJS/TEN in a Thai population, the positive predictive value (PPV) and negative predictive value (NPV) of the HLA‐B*1502 were 1.92% and 99.96%. Results from this study suggest that HLA‐B*1502 may be a useful pharmacogenetic test for screening Thai individuals who may be at risk for CBZ‐induced SJS and TEN.

Effectiveness of green tea on weight reduction in obese Thais: A randomized, controlled trial.

This study was undertaken to investigate the effects of green tea on weight reduction in obese Thais. A randomized, controlled trial involving 60 obese subjects (body mass index, BMI > 25 kg/m2) was conducted. All subjects consumed a Thai diet containing 3 meals (8373.6 kJ/day) for 12 weeks, prepared by the Nutritional Unit at Srinagarind Hospital. The diet contained 65% carbohydrates, 15% protein, and 20% fat. Body weight, BMI, body composition, resting energy expenditure, and substrate oxidation were measured at baseline, and during weeks 4, 8, and 12 of the study. Serum levels of leptin and urine VMA were measured at baseline and during the 12th week. Differences over time and between the treatments (green tea or placebo) over time were determined using two-factor ANOVA with repeated measures. In comparing the two groups, differences in weight loss were 2.70, 5.10, and 3.3 kg during the 4th, 8th, and 12th weeks of the study, respectively. At the 8th and 12th weeks of the study, body weight loss was significantly different (P < 0.05). At the 8th week, the difference in resting energy expenditure was 183.38 kJ/day (P < 0.001), the difference in the respiratory quotient was 0.02 (P < 0.05), and no significant differences existed in satiety score, food intake, or physical activity. Urine VMA was significantly different in the 12th week of the study (P < 0.05). We conclude that green tea can reduce body weight in obese Thai subjects by increasing energy expenditure and fat oxidation.

The effects of transcranial direct current stimulation in patients with neuropathic pain from spinal cord injury

OBJECTIVE Transcranial direct current stimulation (tDCS) has demonstrated efficacy for reducing neuropathic pain, but the respective mechanisms remain largely unknown. The current study tested the hypothesis that pain reduction with tDCS is associated with an increase in the peak frequency spectrum density in the theta-alpha range. METHODS Twenty patients with spinal cord injury and bilateral neuropathic pain received single sessions of both sham and anodal tDCS (2 mA) over the left primary motor area (M1) for 20 min. Treatment order was randomly assigned. Pre- to post-procedure changes in pain intensity and peak frequency of electroencephalogram spectral analysis were compared between treatment conditions. RESULTS The active treatment condition (anodal tDCS over M1) but not sham treatment resulted in significant decreases in pain intensity. In addition, consistent with the study hypothesis, peak theta-alpha frequency (PTAF) assessed from an electrode placed over the site of stimulation increased more from pre- to post-session among participants in the active tDCS condition, relative to those in the sham tDCS condition. Moreover, we found a significant association between a decrease in pain intensity and an increase in PTAF at the stimulation site. CONCLUSIONS The findings are consistent with the possibility that anodal tDCS over the left M1 may be effective, at least in part, because it results in an increase in M1 cortical excitability, perhaps due to a pain inhibitory effect of motor cortex stimulation that may influence the descending pain modulation system. Future research is needed to determine if there is a causal association between increased left anterior activity and pain reduction. SIGNIFICANCE The results provide new findings regarding the effects of tDCS on neuropathic pain and brain oscillation changes.

The Short-Term Effects of Transcranial Direct Current Stimulation on Electroencephalography in Children with Autism: A Randomized Crossover Controlled Trial

Abnormal synaptic maturation and connectivity are possible etiologies of autism. Previous studies showed significantly less alpha activity in autism than normal children. Therefore, we studied the effects of anodal tDCS on peak alpha frequency (PAF) related to autism treatment evaluation checklist (ATEC). Twenty male children with autism were randomly assigned in a crossover design to receive a single session of both active and sham tDCS stimulation (11 mA) over F3 (left dorsolateral prefrontal cortex). Pre- to postsession changes in a measure of cortical activity impacted by tDCS (PAF) and ATEC were compared between groups. We also examined the associations between pre- and postsession changes in the PAF and ATEC. The results show significant pre- to postsession improvements in two domains of ATEC (social and health/behavior domains) following active tDCS, relative to sham treatment. PAF also significantly increased at the stimulation site, and an increase in PAF was significantly associated with improvements in the two domains of ATEC impacted by tDCS. The findings suggest that a single session of anodal tDCS over the F3 may have clinical benefits in children with autism and that those benefits may be related to an increase in PAF.

Effect of anodal transcranial direct current stimulation on autism: a randomized double-blind crossover trial.

The aim of this study was to evaluate the Childhood Autism Rating Scale (CARS), Autism Treatment Evaluation Checklist (ATEC), and Childrens Global Assessment Scale (CGAS) after anodal transcranial direct current stimulation (tDCS) in individuals with autism. Twenty patients with autism received 5 consecutive days of both sham and active tDCS stimulation (1 mA) in a randomized double-blind crossover trial over the left dorsolateral prefrontal cortex (F3) for 20 minutes in different orders. Measures of CARS, ATEC, and CGAS were administered before treatment and at 7 days posttreatment. The result showed statistical decrease in CARS score (P < 0.001). ATEC total was decreased from 67.25 to 58 (P < 0.001). CGAS was increased at 7 days posttreatment (P = 0.042). Our study suggests that anodal tDCS over the F3 may be a useful clinical tool in autism.

Clinical Manifestations of Eosinophilic Meningitis Due to Infection with Angiostrongylus cantonensis in Children

Eosinophilic meningitis, caused by the nematode Angiostrongylus cantonensis, is prevalent in northeastern Thailand, most commonly in adults. Data regarding clinical manifestations of this condition in children is limited and may be different those in adults. A chart review was done on 19 eosinophilic meningitis patients aged less than 15 years in Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand. Clinical manifestations and outcomes were reported using descriptive statistics. All patients had presented with severe headache. Most patients were males, had fever, nausea or vomiting, stiffness of the neck, and a history of snail ingestion. Six patients had papilledema or cranial nerve palsies. It was shown that the clinical manifestations of eosinophilic meningitis due to A. cantonensis in children are different from those in adult patients. Fever, nausea, vomiting, hepatomegaly, neck stiffness, and cranial nerve palsies were all more common in children than in adults.

Pain Reduction in Myofascial Pain Syndrome by Anodal Transcranial Direct Current Stimulation Combined with Standard Treatment: A Randomized Controlled Study

Background:Myofascial pain syndrome (MPS) in the shoulder is among the most prevalent pain problems in the middle-aged population worldwide. Evidence suggests that peripheral and central sensitization may play an important role in the development and maintenance of shoulder MPS. Given previous research supporting the potential efficacy of anodal transcranial direct current stimulation (tDCS) for modulating pain-related brain activity in individuals with refractory central pain, we hypothesized that anodal tDCS when applied over the primary motor cortex (M1) combined with standard treatment will be more effective for reducing pain in patients with MPS than standard treatment alone. Methods and Materials:Study participants were randomized to receive either (1) standard treatment with 5 consecutive days of 1 mA anodal tDCS over M1 for 20 minutes; or (2) standard treatment plus sham tDCS. Measures of pain intensity, shoulder passive range of motion (PROM), analgesic medication use, and self-reported physical functioning were administered before treatment and again at posttreatment and 1-, 2-, 3-, and 4-week follow-up. Results:Thirty-one patients with MPS were enrolled. Participants assigned to the active tDCS condition reported significantly more pretreatment to posttreatment reductions in pain intensity that were maintained at 1-week posttreatment, and significant improvement in shoulder adduction PROM at 1-week follow-up than participants assigned to the sham tDCS condition. Conclusions:Five consecutive days of anodal tDCS over M1 combined with standard treatment appears to reduce pain intensity and may improve PROM, faster than standard treatment alone. Further tests on the efficacy and duration of effects of tDCS in the treatment of MPS are warranted.

Kluver–Bucy syndrome after mycoplasmal bronchitis

Kluver-Bucy syndrome is a rare neurobehavioral condition characterized by visual agnosia, excessive oral tendencies, hypermetamorphosis, placidity, altered sexual behavior, and changes in dietary habits. This description of a 14-year-old boy presenting with complete Kluver-Bucy syndrome after Mycoplasma pneumoniae bronchitis is the first such case report. MRI revealed left temporal horn dilation and asymmetry of both temporal lobes. We hypothesize that the pathophysiology of our case is immune-mediated damage by M. pneumoniae resulting in vasculopathy.

Transcranial Direct Current Stimulation for Treatment of Childhood Pharmacoresistant Lennox–Gastaut Syndrome: A Pilot Study

Background Lennox–Gastaut syndrome (LGS) is a severe childhood epileptic syndrome with high pharmacoresistance. The treatment outcomes are still unsatisfied. Our previous study of cathodal transcranial direct current stimulation (tDCS) in children with focal epilepsy showed significant reduction in epileptiform discharges. We hypothesized that cathodal tDCS when applied over the primary motor cortex (M1) combined with pharmacologic treatment will be more effective for reducing seizure frequency in patients with LGS than pharmacologic treatment alone. Materials and methods Study participants were randomized to receive either (1) pharmacologic treatment with five consecutive days of 2 mA cathodal tDCS over M1 for 20 min or (2) pharmacologic treatment plus sham tDCS. Measures of seizure frequency and epileptic discharges were performed before treatment and again immediately post-treatment and 1-, 2-, 3-, and 4-week follow-up. Result Twenty-two patients with LGS were enrolled. Participants assigned to the active tDCS condition reported significantly more pre- to post-treatment reductions in seizure frequency and epileptic discharges that were sustained for 3 weeks after treatment. Conclusion Five consecutive days of cathodal tDCS over M1 combined with pharmacologic treatment appears to reduce seizure frequency and epileptic discharges. Further studies of the potential mechanisms of tDCS in the LGS are warranted. Trial Registration ClinicalTrials.gov, NCT02731300 (https://register.clinicaltrials.gov).

Transcranial Direct Current Stimulation in Neuropathic Pain

Neuropathic pain (NP) is one of the most common problems contributing to suffering and disability worldwide. Unfortunately, NP is also largely refractory to treatments, with a large number of patients continuing to report significant pain even when they are receiving recommended medications and physical therapy. Thus, there remains an urgent need for additional effective treatments. In recent years, nonpharmacologic brain stimulation techniques have emerged as potential therapeutic options. Many of these techniques and procedures – such as transcranial magnetic stimulation, spinal cord stimulation, deep brain stimulation, and motor cortical stimulation – have very limited availability, particularly in developing countries. Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation procedure that has shown promise for effectively treating NP, and also has the potential to be widely available. This review describes tDCS and the tDCS procedures and principles that may be helpful for treating NP. The findings indicate that the analgesic benefits of tDCS can occur both during stimulation and beyond the time of stimulation. The mechanisms of cortical modulation by tDCS may involve various activities in neuronal networks such as increasing glutamine and glutamate under the stimulating electrode, effects on the μ-opioid receptor, and restoration of the defective intracortical inhibition. Additional research is needed to determine (1) the factors that may moderate the efficacy of tDCS, (2) the dose (e.g. number and frequency of treatment sessions) that results in the largest benefits and (3) the long-term effects of tDCS treatment.