Genetic Susceptibility Variants of Vascular Dementia among Asians: A Systematic Review and Meta-Analysis.

INTRODUCTION: Vascular dementia (VaD), a neurocognitive impairment directly related to vascular injury, is the second most common cause of age-related dementia. Although numerous studies have investigated candidate genetic polymorphisms associated with VaD in Asia, the genetics of VaD remains unclear. METHODS: This review provides an updated meta-analysis of genetic polymorphisms associated with VaD in Asians, using the PRISMA guidelines. Published literature up to May 2021 was extracted from the PubMed, Scopus, Ovid, and EBSCO host databases. Meta-analysis was conducted using the Open Meta analyst, Review Manager, and MedCalc® Statistical Software. Trial sequential analysis (TSA) was performed using TSA viewer software. RESULTS: A total of 46 eligible studies, comprising 23 genes and 35 SNPs, were retrieved. The meta-analysis was conducted on the following genetic polymorphisms, APOE ε2/3/4, MTHFR rs1801131, ACE rs4340 (I/D) gene polymorphism, and a PSEN1 intron 8 variant. The pooled ORs revealed a significant increase in the risk of VaD in the Apolipoprotein E (APOE) ε4 allelic model: OR, 1.79, p<0.001), and the methylenetetrahydrofolate reductase (MTHFR) rs1801133 polymorphism T allele in the allelic model (OR, 1.23, p=0.013). CONCLUSION: Our findings provide evidence that genetic polymorphisms of the APOE ε4 allele and MTHFR rs1801133 T allele increase the risk of developing VaD in Asians. However, future large-scale investigations examining particularly on South-Eastern and West-Asian populations are highly recommended.

Video head impulse test in stroke: a review of published studies.

Accurate and timely diagnosis of posterior circulation stroke in patients with acute dizziness is a challenge that can lead to misdiagnosis and significant harm. The present review sought to identify and describe published research on the clinical application of vHIT in posterior circulation stroke. vHIT, a portable device, has gained prominence in evaluating peripheral vestibular disorders and offers potential applications in diagnosing neurological disorders, particularly posterior circulation stroke. Several studies have shown that vHIT can differentiate between stroke and vestibular neuritis based on VOR gain values, with high sensitivity and specificity. The manuscript also discusses vHIT's performance in differentiating between types of posterior circulation stroke, such as PICA, AICA, and SCA strokes. While vHIT has demonstrated promise, the review emphasizes the need for further research to validate its use as a tool to rule out stroke in acute dizziness patients in the emergency department. In conclusion, the manuscript underscores the potential of vHIT as a valuable addition to the diagnostic arsenal for acute dizziness, particularly in the context of posterior circulation stroke. It calls for further research and wider adoption of vHIT in clinical settings to improve patient care and reduce unnecessary costs associated with misdiagnoses.

Relationship of sleep quality, chronotype, and obstructive sleep apnea with migraine in the elderly population.

PURPOSE: Disturbances of sleep have frequently been reported in individuals with migraine. On top of this, an elderly patient with migraine also suffers from sleep disturbances due to changes in physiologic and mental health associated with aging. This study aimed to compare several sleep factors, namely sleep quality, chronotype, and obstructive sleep apnea (OSA) risk, between elderly people with and without migraine. METHODS: This was a multicenter cross-sectional study conducted in 10 neurologic clinics located in Tehran, Iran, over 2 years. The sample size was calculated as 189, including 63 migraine and 126 non-migraine patients. RESULTS: A significant difference was observed in the mean score of the global Pittsburgh Sleep Quality Index (PSQI) between migraine and non-migraine groups (p-value = 0.002), and in the individual components of the PSQI. However, there were no significant differences in the frequency of different types of chronotype (p-value = 0.125, T = 1.541) or OSA risk between the two groups (p-value = 0.568, T = -0.573). The binary logistic regression model showed that the relationship between global PSQI and migraine was significant (p = 0.002). CONCLUSION: Sleep quality is a problem for elderly migraine sufferers. Meanwhile, certain factors such as chronotype and OSA have no significant relationship with migraine among community-dwelling seniors. Further studies are required to enhance our understanding of this observation.

Association of Endothelin-Converting Enzyme and Endothelin-1 Gene Polymorphisms with Essential Hypertension in Malay Ethnics.

Objectives: Endothelin-1 (ET-1), the most potent endogenous vasoconstrictor, generated by enzymatic cleavage catalyzed by an endothelin-converting enzyme (ECE), plays a significant role in the regulation of hypertension. Methods: This study investigates the effect of endothelin-1 (Lys198Asn/rs5370) and ECE (rs212526 C/T) gene polymorphisms with essential hypertension (EH) among Malay ethnics. To determine the association of gene polymorphism, 177 hypertensives and controls (196) were genotyped using Taqman method. Results: A significant difference was observed in ET-1 rs5370 and ECE rs212526 gene polymorphisms between EH and control subjects (P < 0.001). A significantly high body mass index (BMI), waist-to-hip ratio, fasting plasma glucose, hemoglobin A1c, systolic and diastolic blood pressure, and lipid profiles were observed among the EH patients when compared to controls (P < 0.05). Moreover, T allele (rs5370) carriers in males have a high risk for EH. There was no significant association between gender in ECE C/T polymorphisms (P > 0.05). Conclusion: Based on our result, it is evident that the T allele of ET-1 rs5370 polymorphism and C allele of ECE rs212526 have a significant genetic risk factor in EH among Malay subjects, and BMI and age are associated with hypertension.

High-frequency repetitive transcranial magnetic stimulation at dorsolateral prefrontal cortex for migraine prevention: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the efficacy of high-frequency repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex as a migraine prevention by conducting a systematic review and meta-analysis. BACKGROUND: The efficacy of high-frequency repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex as preventive migraine treatment remains debatable. METHODS: PubMed, Scopus, CINAHL, CENTRAL, and BioMed Central databases were searched from their inception until December 2020. Randomised trials comparing high-frequency repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex with sham for migraine prevention were included. The risk of bias was assessed using the Cochrane guidelines. Headache days, pain intensity, acute medication intake, and disability were extracted as study outcomes and the mean difference with a random-effects model was used to determine the effect size. RESULTS: Meta-analysis revealed that high-frequency repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex significantly reduced acute medication intake (Mean Difference = 9.78, p = 0.02, 95%CI: 1.60, 17.96, p = 0.02) and functional disability (Mean Difference = 8.00, p < 0.05, 95%CI: 4.21, 11.79). However, no differences were found in headache days and pain intensity reduction, although there was a slight trend favouring high-frequency repetitive transcranial magnetic stimulation. CONCLUSION: High-frequency repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex may be effective in reducing acute medication intake and disability. However, more studies are needed to strengthen this preliminary evidence.

Analysis of OCT1, OCT2 and OCT3 gene polymorphisms among Type 2 diabetes mellitus subjects in Indian ethnicity, Malaysia.

BACKGROUND: Type 2 Diabetes mellitus (T2DM) is a chronic metabolic disorder. It is a major non-communicable disease affecting 463 million people globally in 2019 and is expected to be double to about 700 million by 2045. The majority are Asians with Indian ethnicity in Malaysia reported as the highest prevalence of T2DM. Cardiovascular disease, renal failure, blindness and neuropathy, as well as premature death are the known morbidity and mortality resulted from T2DM. T2DM is characterized by the dysfunctional insulin physiology that causes reduction of glucose transport into the cells which lead to hyperglycaemia. Hence, one of the important treatments is an oral antidiabetic drug that lowers the serum glucose level in patients with T2DM. This drug will be transported across cell membranes by organic cation transporters (OCT). Therefore, it is important to identify the OCT candidate gene polymorphisms related to T2DM especially among the Indian ethnicity in Malaysia. METHODS: Blood samples were collected from 132 T2DM patients and 133 controls. Genotyping of OCT1 (rs628031), OCT2 (rs145450955), OCT3 (rs3088442 and rs2292334) was performed using (PCR-RFLP). RESULTS: No association was observed for genotypic and allelic distributions in all the gene polymorphisms of OCT genes (P > 0.05). However, a logistic regression analysis stratified by gender in a dominant model showed a significant difference for OCT3 among males with T2DM (P = 0.006). Significant association was also observed for OCT3 when stratified to subjects aged > 45 years old (P = 0.009). CONCLUSION: Based on these findings, the association of OCT3 (rs2292334) could be considered as a possible genetic risk factor for the development of T2DM among Indian males alone.

High-frequency repetitive transcranial magnetic stimulation at dorsolateral prefrontal cortex for migraine prevention: A protocol for a systematic review of controlled trials.

BACKGROUND: Migraine may lead to a negative impact on the patients' quality of life with a subsequent substantial burden to society. Therapy options for treatment and prevention of migraine have progressed over the years and repetitive transcranial magnetic stimulation (rTMS) is one of the promising non-pharmacological options. It induces and alters electric current in the brain via repetitive non-invasive brain stimulation in high frequency. In migraine patients, two common stimulation sites are the M1 cortex and dorsolateral prefrontal cortex (DLPFC). The mechanism on how rTMS exerts therapeutic effects on migraine is not fully established, but the main postulation is that the neuromodulation via high-frequency rTMS (hf-rTMS) might inhibit pain perception. However, evidence from studies has been conflicting, thus the usefulness of hf-rTMS as migraine preventive treatment is still uncertain at this moment. METHODS: This is a systematic review protocol describing essential reporting items based on the PRISMA for systematic review protocols (PRISMA-P) (Registration number: CRD42020220636). We aim to review the effectiveness, tolerability, and safety of hf-rTMS at DLPFC in randomised controlled trials (RCTs) as migraine prophylactic treatment. We will search Scopus, Cumulative Index to Nursing and Allied Health Literature Plus, PubMed, Cochrane Central Register of Controlled Trials and Biomed Central for relevant articles from randomised controlled clinical trials that used hf-rTMS applied at DLPFC for the treatment of migraine. The risk of bias will be assessed using the version 2 "Risk of bias" tool from Cochrane Handbook for Systematic Reviews of Interventions Version 6.1. We will investigate the evidence on efficacy, tolerability and safety and we will compare the outcomes between the hf-rTMS intervention and sham groups. DISCUSSION: This systematic review will further determine the efficacy, safety, and tolerability of hf-rTMS applied at DLPFC for migraine prophylaxis. It will provide additional data for health practitioners and policymakers about the usefulness of hf-rTMS for migraine preventive treatment.

Effectiveness and tolerability of repetitive transcranial magnetic stimulation for preventive treatment of episodic migraine: a single-centre, randomised, double-blind, sham-controlled phase 2 trial (Magnet-EM).

BACKGROUND: This is a phase II randomised, double-blind, sham-controlled trial to evaluate the effectiveness and tolerability of repetitive transcranial magnetic stimulation for preventive treatment of episodic migraine amongst migraine subjects. METHODS: Subjects age 18 to 60 years will undergo a baseline evaluation to establish the diagnosis of migraine based on the International Classification of Headache Disorder 3rd Edition (ICHD-3). Those who fulfil the ICHD-3 criteria for episodic migraine and compliant to the headache diary during a month run-in period will be enrolled. A total of 76 subjects will be randomised to receive either transcranial magnetic stimulation or sham stimulation for 5 sessions within 2 weeks duration. Follow-up sessions will be conducted monthly for three consecutive months. Prior to treatment, subjects will be required to fill up questionnaires and undergo few procedures such as electroencephalography, transcranial Doppler ultrasound and biochemical analysis for serum serotonin, serum calcitonin gene-related peptide and serum beta-endorphin. These procedures will be repeated at month 3 after receiving the last treatment. The primary outcome measure of this study is the difference in mean monthly migraine days at baseline and at months 1, 2 and 3 after treatment sessions. DISCUSSION: Following evidence from previous studies showing restoration of dorsolateral prefrontal cortex (DLPFC) activation to almost normal level, the rTMS intervention will target left DLPFC in this study. An intermediate duration of treatment sessions is selected for this study. It is set to five treatment sessions given within 2 weeks duration. TRIAL REGISTRATION: ClinicalTrials.gov NCT03556722 . Registered on 14 June 2018.

Anti-Wolbachia therapy for onchocerciasis & lymphatic filariasis: Current perspectives.

Onchocerciasis and lymphatic filariasis (LF) are human filarial diseases belonging to the group of neglected tropical diseases, leading to permanent and long-term disability in infected individuals in the endemic countries such as Africa and India. Microfilaricidal drugs such as ivermectin and albendazole have been used as the standard therapy in filariasis, although their efficacy in eliminating the diseases is not fully established. Anti-Wolbachia therapy employs antibiotics and is a promising approach showing potent macrofilaricidal activity and also prevents embryogenesis. This has translated to clinical benefits resulting in successful eradication of microfilarial burden, thus averting the risk of adverse events from target species as well as those due to co-infection with loiasis. Doxycycline shows potential as an anti-Wolbachia treatment, leading to the death of adult parasitic worms. It is readily available, cheap and safe to use in adult non-pregnant patients. Besides doxycycline, several other potential antibiotics are also being investigated for the treatment of LF and onchocerciasis. This review aims to discuss and summarise recent developments in the use of anti-Wolbachia drugs to treat onchocerciasis and LF.

Association of HTRA1 and ARMS2 gene polymorphisms with response to intravitreal ranibizumab among neovascular age-related macular degenerative subjects.

BACKGROUND: The association of HTRA1 rs11200638 and ARMS2 rs10490924 gene polymorphisms with response to intravitreal ranibizumab therapy among neovascular AMD (nAMD) subjects in Malaysia was determined in this study, followed by the expression of HTRA1 and ARMS2 genes. RESULTS: Both single nucleotide polymorphisms (SNPs) recorded a significant association between nAMD and controls with HTRA1 rs11200638 at P = 0.018 (OR = 1.52, 95% CI = 1.07-215) and ARMS2 rs10490924 at P < 0.001 (OR = 2.44, 95% CI = 1.75-3.42). An association was also observed in response to ranibizumab for both SNPs in a logistic regression analysis (P < 0.001). The mRNA levels in the HTRA1 variant between responder and non-responder groups were significantly different for the homozygous non-risk GG genotype (P = 0.032). CONCLUSIONS: The HTRA1 rs11200638 and ARMS2 rs10490924 gene polymorphisms are associated with nAMD among Malaysians. Both gene polymorphisms were also correlated with response to intravitreal ranibizumab therapy based on visual and anatomical outcomes especially the HTRA1 rs11200638 variant.

Prevalence and risk factors of gestational diabetes mellitus in Asia: a systematic review and meta-analysis.

BACKGROUND: Gestational diabetes mellitus (GDM) is a of the major public health issues in Asia. The present study aimed to determine the prevalence of, and risk factors for GDM in Asia via a systematic review and meta-analysis. METHODS: We systematically searched PubMed, Ovid, Scopus and ScienceDirect for observational studies in Asia from inception to August 2017. We selected cross sectional studies reporting the prevalence and risk factors for GDM. A random effects model was used to estimate the pooled prevalence of GDM and odds ratio (OR) with 95% confidence interval (CI). RESULTS: Eighty-four studies with STROBE score ≥ 14 were included in our analysis. The pooled prevalence of GDM in Asia was 11.5% (95% CI 10.9-12.1). There was considerable heterogeneity (I2 > 95%) in the prevalence of GDM in Asia, which is likely due to differences in diagnostic criteria, screening methods and study setting. Meta-analysis demonstrated that the risk factors of GDM include history of previous GDM (OR 8.42, 95% CI 5.35-13.23); macrosomia (OR 4.41, 95% CI 3.09-6.31); and congenital anomalies (OR 4.25, 95% CI 1.52-11.88). Other risk factors include a BMI ≥25 kg/m2 (OR 3.27, 95% CI 2.81-3.80); pregnancy-induced hypertension (OR 3.20, 95% CI 2.19-4.68); family history of diabetes (OR 2.77, 2.22-3.47); history of stillbirth (OR 2.39, 95% CI 1.68-3.40); polycystic ovary syndrome (OR 2.33, 95% CI1.72-3.17); history of abortion (OR 2.25, 95% CI 1.54-3.29); age ≥ 25 (OR 2.17, 95% CI 1.96-2.41); multiparity ≥2 (OR 1.37, 95% CI 1.24-1.52); and history of preterm delivery (OR 1.93, 95% CI 1.21-3.07). CONCLUSION: We found a high prevalence of GDM among the Asian population. Asian women with common risk factors especially among those with history of previous GDM, congenital anomalies or macrosomia should receive additional attention from physician as high-risk cases for GDM in pregnancy. TRIAL REGISTRATION: PROSPERO (2017: CRD42017070104 ).

Acute disseminated encephalomyelitis in dengue viral infection.

Dengue is the most common arboviral disease affecting many countries worldwide. An RNA virus from the flaviviridae family, dengue has four antigenically distinct serotypes (DEN-1-DEN-4). Neurological involvement in dengue can be classified into dengue encephalopathy immune-mediated syndromes, encephalitis, neuromuscular or dengue muscle dysfunction and neuro-ophthalmic involvement. Acute disseminated encephalomyelitis (ADEM) is an immune mediated acute demyelinating disorder of the central nervous system following recent infection or vaccination. This monophasic illness is characterised by multifocal white matter involvement. Many dengue studies and case reports have linked ADEM with dengue virus infection but the association is still not clear. Therefore, this article is to review and discuss concerning ADEM in dengue as an immune-medicated neurological complication; and the management strategy required based on recent literature.