Neurology Research International最新文献

Minimal myelination is proposed to be a contributing factor to the preferential nigral neuronal loss in Parkinson's disease (PD). Similar to nigral dopaminergic neurons, sympathetic neurons innervating the heart have long, thin axons which are unmyelinated or minimally myelinated. Interestingly, cardiac sympathetic loss in PD is heterogeneous across the heart, yet the spatial relationship between myelination and neurodegeneration is unknown. Here, we report the mapping of myelin basic protein (MBP) expression across the left ventricle of normal rhesus macaques (n = 5) and animals intoxicated with systemic 6-OHDA (50 mg/kg iv) to model parkinsonian cardiac neurodegeneration (n = 10). A subset of 6-OHDA-treated rhesus received daily dosing of pioglitazone (5 mg/kg po; n = 5), a PPARγ agonist with neuroprotective properties. In normal animals, MBP-immunoreactivity (-ir) was identified surrounding approximately 14% of axonal fibers within nerve bundles of the left ventricle, with more myelinated nerve fibers at the base level of the left ventricle than the apex (p < 0.014). Greater MBP-ir at the base was related to a greater number of nerve bundles at that level relative to the apex (p < 0.05), as the percent of myelinated nerve fibers in bundles was not significantly different between levels of the heart. Cardiac sympathetic loss following 6-OHDA was associated with decreased MBP-ir in cardiac nerve bundles, with the percent decrease of MBP-ir greater in the apex (84.5%) than the base (52.0%). Interestingly, cardiac regions and levels with more MBP-ir in normal animals showed attenuated sympathetic loss relative to areas with less MBP-ir in 6-OHDA + placebo (r = -0.7, p < 0.014), but not in 6-OHDA + pioglitazone (r = -0.1) subjects. Our results demonstrate that myelination is present around a minority of left ventricle nerve bundle fibers, is heterogeneously distributed in the heart of rhesus macaques, and has a complex relationship with cardiac sympathetic neurodegeneration and neuroprotection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus that causes coronavirus disease 2019 (COVID-19). The latest data show that more than 211.7 million people were infected and more than 4.4 million deaths have been reported. The illness presents a wide range of symptoms, ranging from mild to severe. Mild symptoms include cough, fever, dyspnea, fatigue, myalgia and arthralgia, anosmia, and dysgeusia. Furthermore, this virus can affect the central nervous system (CNS) and present a range of mild to severe nervous symptoms, from headache and dysphoria to loss of consciousness, coma, paralysis, and acute cerebrovascular disease. The virus can enter nonneuronal cells of the olfactory epithelium and cause a complete loss of smell. Anosmia and hyposmia are commonly reported in clinics, and being asymptomatic or showing mild symptoms can be primary symptoms in early infected persons. Dysgeusia/hypogeusia is another symptom presented with anosmia/hyposmia. In this article, we reviewed the articles of anosmia and suggested a possible mechanism for this.

Children with attention deficit hyperactivity disorder (ADHD) are prone to peer rejection and disliking due to difficulties in social perception and interaction. To address social perception impairments in ADHD, we examined children with ADHD in a noisy biological motion (BM) direction discrimination paradigm in association with sociocognitive factors including emotion regulation, theory of mind (TOM), and working memory compared to healthy controls. Our results showed that children with ADHD were poorer in discriminating BM direction in noisy environments (F (1, 36) = 4.655, p=0.038). Moreover, a significant correlation was found between working memory and TOM with BM discrimination in an ADHD group (r = 0.442, p=0.01, and r = 0.403, p=0.05, respectively). Our findings could suggest that social perception in noisy scenarios may be affected by memory and social cognitive abilities of children with ADHD.

Epilepsy as a common neurological disease is mostly managed effectively with antiepileptic medications. One-third of patients do not respond to medical treatments requiring alternative therapies. Vagus nerve stimulation (VNS) has been used in the last decades for the treatment of medically resistant epilepsy. Despite the extensive use of VNS in these patients, factors associated with clinical outcomes of VNS remain to be elucidated. In this study, we evaluated factors affecting VNS outcomes in epileptic patients to have a better understanding of patients who are better candidates for VNS therapy. Several databases including PubMed, Scopus, and Google Scholar were searched through June 2020 for relevant articles. The following factors were assessed in this review: previous surgical history, age at implantation and gender, types of epilepsy, duration of epilepsy, age at epilepsy onset, frequency of attacks, antiepileptic drugs, VNS parameters, EEG findings, MRI findings, and biomarkers. Literature data show that nonresponder rates range between 25% and 65%. Given the complexity and diversity of factors associated with response to VNS, more clinical studies are needed to establish better paradigm for selection of patients for VNS therapy.

Background: The aim of this observational study is to investigate the efficacy and safety of two approved oral disease-modifying therapies (DMTs) in patients with remitting-relapsing multiple sclerosis (RRMS): dimethyl fumarate (DMF) vs. teriflunomide (TRF).

Methods: A total of 159 RRMS patients (82 on TRF and 77 on DMF) were included. The expanded disability status scale (EDSS), confirmed disability improvement (CDI), confirmed disability progression (CDP), and annualized relapse rate (ARR) were evaluated for the two-year period prior to enrollment in our study. The drug-associated adverse effects (AEs) were recorded. We conducted propensity matching score to compare the efficacy between TRF and DMF.

Results: After matching for the confounders, TRF- and DMF-treated groups were not different in terms of EDSS (P value = 0.54), CDI (P value = 0.80), CDP (P value = 0.39), and ARR (P value >0.05). TRF discontinuation occurred in 2 patients (2.43%) due to mediastinitis and liver dysfunction, while a patient (1.29%) discontinued DMF due to depression. Incidence rate of AEs in the TRF-treated group was 81.4%: hair thinning (hair loss) (62.9%), nail loss (20.9%), and elevated aminotransferase (14.8%) were the most common AEs; in DMF-treated patients, AEs were 88.2% with predominance of flushing (73.2%), pruritus (16.9%), and abdominal pain (16.9%).

Conclusion: Based on our findings, DMF is as efficacious and safe as TRF for the treatment of RRMS in our Iranian study population. Multicentric studies need to corroborate these findings in other populations.

Status epilepticus (SE), a subset of epilepsy, represents a debilitating neurological disorder often associated with alarming mortality and morbidity numbers. Even though SE is one of the extensively researched topics with conspicuous data available in the literature, a scientific gap exists in understanding the heterogeneous facets of the disorder like occurrence, definition, classification, causes, molecular mechanisms, etc., thereby providing a defined management program. Cognizance of this heterogeneity and scientific limitation with its subsequent correlation to the recent advancements in medical and scientific domains would serve not only in bridging the gap but also in developing holistic and prompt management programs. Keeping this as an objective, an extensive literature survey was performed during this study, and key findings have been shared. The present study provides a semantic and perspective synopsis toward acknowledging the diversified nature of SE and its variants with respect to their definition, classification, etiology, diagnosis, and management.

Chronic pain is one of the leading causes of disability and disease burden worldwide, accounting for a prevalence between 6.9% and 10% in the general population. Pharmacotherapy alone results ineffective in about 70-60% of patients in terms of a satisfactory degree of pain relief. Focused ultrasound is a promising tool for chronic pain management, being approved for thalamotomy in chronic neuropathic pain and for bone metastases-related pain treatment. FUS is a noninvasive technique for neuromodulation and for tissue ablation that can be applied to several tissues. Transcranial FUS (tFUS) can lead to opposite biological effects, depending on stimulation parameters: from reversible neural activity facilitation or suppression (low-intensity, low-frequency ultrasound, LILFUS) to irreversible tissue ablation (high-intensity focused ultrasounds, HIFU). HIFU is approved for thalamotomy in neuropathic pain at the central nervous system level and for the treatment of facet joint osteoarthritis at the peripheral level. Potential applications include HIFU at the spinal cord level for selected cases of refractory chronic neuropathic pain, knee osteoarthritis, sacroiliac joint disease, intervertebral disc nucleolysis, phantom limb, and ablation of peripheral nerves. FUS at nonablative dosage, LILFUS, has potential reversible and tissue-selective effects. FUS applications at nonablative doses currently are at a research stage. The main potential applications include targeted drug and gene delivery through the Blood-Brain Barrier, assessment of pain thresholds and study of pain, and reversible peripheral nerve conduction block. The aim of the present review is to describe the approved and potential applications of the focused ultrasound technology in the field of chronic pain management.

Background: Distinguishing the category of stroke plays a vital role in planning patient care. Simple clinical findings help distinguish the type of stroke. However, there is a need for diagnostic imaging. In Ethiopia, stroke is the most common neurological condition in patients admitted to hospitals. Yet, there are limited data on comparisons of stroke subtypes. Thus, this study was designed to determine the prevalence of stroke and to compare ischemic and hemorrhagic strokes.

Methods: A retrospective cross-sectional study design was employed. Medical records containing complete information and confirmed diagnosis using imaging techniques were included. The data were entered into SPSS version 24.0 for analysis. Results with a P value of <0.05 were considered statistically significant.

Results: From a total of 312 stroke patients, 204 (65.4%) patients were admitted due to ischemic stroke. More females, 59 (18.9%), were admitted for hemorrhagic stroke than males. In both ischemic, 175 (56.1%) and hemorrhagic, 91 (29.2%) stroke cases, most of the patients were 45 years and above. Middle cerebral artery territory was the most common site of arterial territory infarctions in ischemic stroke, 158 (50.7%). Middle cerebral artery territory also was the most common site of hematoma in hemorrhagic stroke, 91 (29.2%). Infarctions in more than one lobe of the cerebrum (16.4%) and intracerebral hemorrhage in multiple areas of the cerebrum (7.4%) were observed in ischemic as well as hemorrhagic stroke cases. Most of the ischemic, 124 (39.8%), and hemorrhagic, 39 (12.5%), stroke patients presented loss of sensation and weakness of body parts. Hypertension was observed in 124 (39.8%) ischemic and 73 (23.4%) hemorrhagic stroke patients. The mortality rate of ischemic stroke, 47 (15.3%), was two times higher than hemorrhagic stroke, 20 (6.5%). Hypertension was the most common predictor of death in both ischemic and hemorrhagic stroke cases.

Conclusions: Ischemic stroke is a common type of stroke in the medical ward of the study hospital. More females were affected by hemorrhagic stroke than males. Middle cerebral artery territory was the most affected area of the brain in both ischemic and hemorrhagic strokes. Most ischemic and hemorrhagic stroke patients were admitted due to loss of sensation and weakness of body parts. Hypertension was the most common risk factor of stroke as well as a predictor of stroke-related deaths. Identification of the stroke subtypes may be important in the management of stroke. Thus, health professionals, government officials, community leaders, and the population at large could be involved in creating awareness about antecedent risk factors and clinical presentations of stroke subtypes.

Background: Multiple sclerosis (MS) is an autoimmune disease characterized by inflammation and demyelination of the central nervous system which often involves the optic nerve even though only 20% of the patients experience optic neuritis (ON).

Objective: This study aims to compare the retinal structure and optic nerve function between patients with MS and healthy controls (HCs), evaluate optic nerve alterations in MS over 1-year follow-up, and analyze its correlations with disease duration, number of relapses, degree of disability, and different subtypes.

Methods: This is a prospective cohort study involving 58 eyes of MS patients. Optic nerve function was evaluated with best-corrected visual acuity (BCVA), contrast sensitivity, and P100 latency, while the retinal structure was evaluated from the GCIPL and RNFL thickness measured with optical coherence tomography (OCT) and fundus photography.

Results: The MS group had lower BCVA (p=0.001), contrast sensitivity (p < 0.001), mean GCIPL thickness (p < 0.001), and mean RNFL thickness (p < 0.001) than HC. At 6 and 12 months of observations, GCIPL and RNFL (nasal quadrant) of MS patients decreased significantly (p=0.007 and p=0.004, respectively). Disease duration and the number of relapses correlated with delayed P100 latency (r = -0.61, p < 0.001 and r = -0.46, p=0.02). GCIPL and RNFL in the SPMS subtype were thinner than in RRMS.

Conclusions: The retinal structure and optic nerve function of MS patients are worse than those of normal individuals. GCIPL and RNFL thinning occurs at 6 and 12 months but do not correlate with disease duration, the number of relapses, and degree of disability.

Introduction: Stroke recurrence accounts for a great percentage of catastrophic complications, yet no comprehensive study has analyzed the factors associated with stroke recurrence in Cameroon. We carried out this case-control study to better understand the factors associated with the stroke recurrence in Cameroon.

Methods: We collected sociodemographic, clinical, neuroimaging, laboratory, and therapeutic data of eligible patients who consulted the neurology and cardiology department of the Yaounde Central Hospital in Cameroon. We included all patients at least five years removed from their first stroke event who consulted the authors' institution as of January 15, 2019. Wilcoxon signed-rank and Fisher's exact tests were used. Also, a Cox regression model was used to identify confounders.

Results: We recruited 100 patients; seven out of ten patients had hypertension, while six out of 10 had a sedentary lifestyle. Half of the patients consumed alcohol regularly, while one patient out of five had diabetes. Most patients presented with their first stroke event, and a quarter had a stroke recurrence. Stroke recurrence was associated with right handedness (OR = 0.23, 95% CI = 0.16-0.33), congestive heart failure (OR = 3.45, 95% CI = 1.16-10.28), gout (OR = 4.34, 95% CI = 1.09-18.09), dysarthria (OR = 4.34, 95% CI = 1.30-14.54), and facial palsy (OR = 3.96, 95% CII = 1.49 - 10.51), as well as modifiable factors such as elevated abdominal circumference (P < 0.01), systolic blood pressure (P < 0.01), blood glucose level (PI P < 0.01), and triglyceride levels (P < 0.01). The mulitvariable regression model only identified laterality (B = -1.48, P = 0.04) as a statistically significant explanatory varibale for stroke recurrence.

Conclusion: We mapped the landscape of recurrent strokes in Cameroon. There is a need to evaluate the causes of suboptimal drug adherence rates and both the role and adherence to nonpharmacologic interventions.