Assessment of Cortical Plasticity in Schizophrenia by Transcranial Magnetic Stimulation.

Neural plasticity refers to the capability of the brain to modify its structure and/or function and organization in response to a changing environment. Evidence shows that disruption of neuronal plasticity and altered functional connectivity between distinct brain networks contribute significantly to the pathophysiological mechanisms of schizophrenia. Transcranial magnetic stimulation has emerged as a noninvasive brain stimulation tool that can be utilized to investigate cortical excitability with the aim of probing neural plasticity mechanisms. In particular, in pathological disorders, such as schizophrenia, cortical dysfunction, such as an aberrant excitatory-inhibitory balance in cortical networks, altered cortical connectivity, and impairment of critical period timing are very important to be studied using different TMS paradigms. Studying such neurophysiological characteristics and plastic changes would help in elucidating different aspects of the pathophysiological mechanisms underlying schizophrenia. This review attempts to summarize the findings of available TMS studies with diagnostic and characterization aims, but not with therapeutic purposes, in schizophrenia. Findings provide further evidence of aberrant excitatory-inhibitory balance in cortical networks, mediated by neurotransmitter pathways such as the glutamate and GABA systems. Future studies with combining techniques, for instance, TMS with brain imaging or molecular genetic typing, would shed light on the characteristics and predictors of schizophrenia.

The battle against the COVID-19 pandemic- a perspective from Saudi Arabia.

COVID-19 has emerged as the world's biggest challenge that has not only threatened human lives but also had an immense impact on the economy, safety and religious practices. The situation has worsened due to the lack of proper guidelines for fighting the sudden unexpected outbreaks. The world was not prepared for this situation. Muslims make up the largest religious group in the world, and Saudi Arabia is the center of religious life for Muslims. The eye of the Muslim world is turned toward the measures and reforms that the Saudi state is implementing during this pandemic, including strict curfews and quarantines with heavy fines and punishments for violations. This review highlights some important steps the Saudi government is taking and their impact on controlling the COVID-19 outbreak.

The effect of transcranial direct current stimulation combined with functional task training on motor recovery in stroke patients.

BACKGROUND: Motor deficits are common after stroke and are a major contributor to stroke-related disability and the potential for long-lasting neurobiological consequences of stroke remains unresolved. There are only a few treatments available for the improvement of motor function in stroke patients. However, the mechanisms underlying stroke recovery remain poorly understood, and effective neurorehabilitation interventions remain insufficiently proven for widespread implementation. METHODS: Herein, we propose to enhance the effects of brain plasticity using a powerful noninvasive technique for brain modulation consisting of navigated transcranial magnetic stimulation (TMS) priming with transcranial direct current stimulation (tDCS) in combination with motor-training-like constraint-induced movement therapy (CIMT). Our hypothesis is that navigated low-frequency rTMS stimulus priming with precise location provided by neuronavigation on the healthy side of the brain and with anodal tDCS on the affected side combined with CIMT will induce a greater motor function improvement than that obtained with sham tDCS combined with CIMT alone. We predict that the application of this technique will result in a large reduction in cortical excitability and dis-inhibition in the affected hemisphere and lead to improvements in behavioral measures of hand function in stroke patients. DISCUSSION: The proposed study, therefore, is important for several reasons. The results could potentially lead to improved stroke therapeutics, and the approach makes use of 2 potential pathways to modulate brain function. TRIAL REGISTRATION: This study protocol was registered in Clinical Trials Registry (https://clinicaltrials.gov/ct2/show/NCT04646577). ETHICS AND DISSEMINATION: The study has been reviewed and approved by the Human Research Ethics Committee of the King Fahad Specialist Hospital Dammam. The results will be actively disseminated through peer-reviewed journals, conference presentations, social media, broadcast media, print media, the internet and various community/stakeholder engagement activities.

Neuromyelitis optica spectrum disorders in Arabian Gulf (NMOAG); establishment and initial characterization of a patient registry.

OBJECTIVE: To describe the clinical and radiological characteristics of neuromyelitis optica spectrum disorders (NMOSD) patients from the Arabian Gulf relative to anti-aquaporin 4 antibody serostatus. METHODS: Retrospective multicentre study of hospital records of patients diagnosed with NMOSD based on 2015 International Panel on NMOSD Diagnosis (IPND) consensus criteria. RESULTS: One hundred forty four patients were evaluated, 64.3% were anti-AQP4 antibody positive. Mean age at onset and disease duration were 31±12 and 7 ±â€¯6 years respectively. Patients were predominantly female (4.7:1). Overall; relapsing course (80%) was more common than monophasic (20%). Optic neuritis was the most frequent presentation (48.6%), regardless of serostatus. The proportion of patients (54.3%) with visual acuity of ≤ 0.1 was higher in the seropositive group (p = 0.018). Primary presenting symptoms of transverse myelitis (TM) were observed in 29% of patients, and were the most significant correlate of hospitalization (p<0.001). Relative to anti-APQ4 serostatus, there were no significant differences in terms of age of onset, course, relapse rates or efficacy outcomes except for oligoclonal bands (OCB), which were more often present in seronegative patients (40% vs.22.5%; p = 0.054). Irrespective of serostatus, several disease modifying therapies were instituted including steroids or immunosuppressives, mostly, rituximab and azathioprine in the cohort irrespective of serostatus. The use of rituximab resulted in reduction in disease activity. CONCLUSION: This is the first descriptive NMOSD cohort in the Arabian Gulf region. Seropositive patients were more prevalent with female predominance. Relapsing course was more common than monophasic. However, anti-AQP4 serostatus did not impact disease duration, relapse rate or therapeutic effectiveness. These findings offer new insights into natural history of NMOSD in patients of the Arabian Gulf and allow comparison with patient populations in different World regions.