BackgroundThe prevalence of dementia varies around the world, potentially contributed to by international differences in rates of age-related cognitive decline. Our primary goal was to investigate how rates of age-related decline in cognitive test performance varied among international cohort studies of cognitive aging. We also determined the extent to which sex, educational attainment, and apolipoprotein E ε4 allele (APOE*4) carrier status were associated with decline.Methods and findingsWe harmonized longitudinal data for 14 cohorts from 12 countries (Australia, Brazil, France, Greece, Hong Kong, Italy, Japan, Singapore, Spain, South Korea, United Kingdom, United States), for a total of 42,170 individuals aged 54–105 y (42% male), including 3.3% with dementia at baseline. The studies began between 1989 and 2011, with all but three ongoing, and each had 2–16 assessment waves (median = 3) and a follow-up duration of 2–15 y. We analyzed standardized Mini-Mental State Examination (MMSE) and memory, processing speed, language, and executive functioning test scores using linear mixed models, adjusted for sex and education, and meta-analytic techniques. Performance on all cognitive measures declined with age, with the most rapid rate of change pooled across cohorts a moderate -0.26 standard deviations per decade (SD/decade) (95% confidence interval [CI] [-0.35, -0.16], p < 0.001) for processing speed. Rates of decline accelerated slightly with age, with executive functioning showing the largest additional rate of decline with every further decade of age (-0.07 SD/decade, 95% CI [-0.10, -0.03], p = 0.002). There was a considerable degree of heterogeneity in the associations across cohorts, including a slightly faster decline (p = 0.021) on the MMSE for Asians (-0.20 SD/decade, 95% CI [-0.28, -0.12], p < 0.001) than for whites (-0.09 SD/decade, 95% CI [-0.16, -0.02], p = 0.009). Males declined on the MMSE at a slightly slower rate than females (difference = 0.023 SD/decade, 95% CI [0.011, 0.035], p < 0.001), and every additional year of education was associated with a rate of decline slightly slower for the MMSE (0.004 SD/decade less, 95% CI [0.002, 0.006], p = 0.001), but slightly faster for language (-0.007 SD/decade more, 95% CI [-0.011, -0.003], p = 0.001). APOE*4 carriers declined slightly more rapidly than non-carriers on most cognitive measures, with processing speed showing the greatest difference (-0.08 SD/decade, 95% CI [-0.15, -0.01], p = 0.019). The same overall pattern of results was found when analyses were repeated with baseline dementia cases excluded. We used only one test to represent cognitive domains, and though a prototypical one, we nevertheless urge caution in generalizing the results to domains rather than viewing them as test-specific associations. This study lacked cohorts from Africa, India, and mainland China.ConclusionsCognitive performance declined with age, and more rapidly with increasing age, across samples from diverse ethnocultural groups and geographical regions. Associations varied a...

Background: Vitamin D is an important secosteroid which is involved the development and regulation of brain activity. Several studies have focused on exploring the relationship between serum vitamin D levels and Parkinson's disease (PD), but the conclusion remains ambiguous.Methods: We searched observational studies that explored the association between serum vitamin D levels and PD based on PubMed, EMBASE and Cochrane library from inception through to January 2018. The quality of included studies was evaluated by using Newcastle-Ottawa Scale (NOS). Statistical analysis of this meta-analysis was performed by Stata version 12.0 and R software.Results: Twenty studies with a total of 2,866 PD patients and 2,734 controls were included. Compared with controls, PD patients had lower serum vitamin D levels (WMD −3.96, 95%CI −5.00, −2.92), especially in higher latitude regions (WMD −4.20, 95%CI −5.66, −2.75). Assay methods contributed significantly to high heterogeneity. Furthermore, PD patients with deficient vitamin D levels had advanced risk (OR 2.08, 95%CI 1.35, 3.19) than those patients with insufficient ones (OR = 1.73, 95%CI 1.48, 2.03). In addition, serum vitamin D levels were also related to the severity of PD (WMD −5.27, 95%CI −8.14, −2.39) and the summary correlation coefficient showed strongly negative correlation (r = −0.55, 95%CI −0.73, −0.29). Moreover, the pooled correlation coefficient revealed that serum vitamin D levels were also negatively correlated to the Unified Parkinson's Disease Rating Scale III (UPDRS III) (r = −0.36, 95%CI −0.53, −0.16), but did not correlate with the duration of PD (P = 0.37) and age of patients (P = 0.49).Conclusion: Serum vitamin D levels are inversely associated with the risk and severity of PD. Our results provided an updated evidence of association between low vitamin D levels and PD and prompt the adjunctive therapeutic decisions about vitamin D replacement in PD.

Blood vessels that supply and feed the central nervous system (CNS) possess unique and exclusive properties, named as blood–brain barrier (BBB). It is responsible for tight regulation of the movement of ions, molecules, and cells between the blood and the brain thereby maintaining controlled chemical composition of the neuronal milieu required for appropriate functioning. It also protects the neural tissue from toxic plasma components, blood cells and pathogens from entering the brain. In this review the importance of BBB and its disruption causing brain pathology and progression to different neurological diseases like Alzheimer’s disease (AD), Parkinson’s disease (PD), Amyotrophic lateral sclerosis (ALS), Huntington’s disease (HD) etc. will be discussed.

Parkinson’s disease (PD) is thought to be the most common neurodegenerative disease with movement disorder. The key motor symptoms are rigidity, tremor, akinesis/hypokinesia/bradykinesia, and postural instability. However, in our day-to-day clinical practice we tend to see several other symptoms which may be motor or non-motor. Non-motor symptoms (NMS) are quite common and debilitating. The pathological hallmarks of PD are loss of dopaminergic neurons in the substantia nigra pars compacta (SNPc) and accumulation of unfolded or misfolded alpha-synuclein. Diagnosis of PD is difficult in the pre-motor stage. Late diagnosis renders a substantial loss of dopaminergic neurons in SNPc and spread of disease in other parts of the brain. This may manifest as either full blown symptoms requiring multiple medications or may even lead to life threatening condition due to lack of early diagnostic tools and techniques. Biomarkers are required to diagnose PD at a very early stage when prevention is possible. Hence, we see a lot of interest among researchers involved in finding a biomarker specific to the disease. Biomarkers may be clinical, image based, genetic, and biochemical. Cerebrospinal fluid (CSF) and serum markers which may correlate with disease pathophysiology are of great significance. One such molecule which recently gained a lot of attention is neuron-specific enolase (NSE). The main aim of this paper is to highlight the role of NSE in predicting neurodegeneration and neuroinflammation ultimately reflecting damage of brain cells in PD.

Background and Objectives:Tuberculosis (TB) is an important cause of childhood morbidity and mortality with different clinical presentations and outcomes as compared to TB in adults. The present study was designed to compare these differences and to determine if childhood TB was an important predictor of adverse outcome following treatment under the Revised National Tuberculosis Control Program (RNTCP).Materials and Methods:Retrospective record based study of cases registered between January 2008 and December 2011, at the Amdanga TB Unit (TU), West Bengal.Results:Of the total 1,508 cases notified, 3.4% were childhood TB. Differences with adult TB were noted in the number of cases categorized as cat II and III in children (P = 0.012 and 0.000, respectively). New smear positive pulmonary TB was significantly lower (21.6%, P = 0.000), while new extra-pulmonary TB (39.2%, P = 0.000) was significantly higher in children. Smear negative cases comprised 7.8 and 11.4% of the childhood and adult cases of TB, respectively. Retreatment cases were significantly higher in adults (P = 0.012). Among the registered new smear positive cases, the differences in favourable and adverse outcomes did not have a significant statistical difference (P = .100). Childhood TB was not a significant risk factor for adverse outcome following treatment (adjusted odds ratio [AOR] = 0.80, 95% confidence interval [CI] = 0.28–2.32).Conclusions:The registration of childhood TB under the RNTCP in the TU was low. There were differences in the clinical presentation and treatment outcomes of TB among children and adults. Childhood TB was not a significant predictor of adverse treatment following treatment.

Medical benefits of cannabis and related compounds is widely known. Discovery of psychotropic plant cannabinoid Δ9-tetrahydrocannabinol have urged researchers to study more about the cannabinoid system and related therapeutics in the field of neurology and medicine. Where activation of cannabinoid receptor type 1 (CB1R) yielded in unwanted and serious side effects, discovery of cannabinoid receptor type 2 (CB2R) and its ligands gave a new hope. Till now there is limited success in this field because of complex expanded endocannabinoid system comprising of receptors, ligands and enzymes. In this review we will update about the role of endocannabinoidome relevant to neurological disorders.

Huntington’s disease (HD) is an incurable neurodegenerative disease that causes involuntary movements, emotional lability, and cognitive dysfunction. HD symptoms usually develop between ages 30 and 50, but can appear as early as 2 or as late as 80 years. Currently no neuroprotective and neurorestorative interventions are available. Early multimodal intervention in HD is only possible if the genetic diagnosis is made early. Early intervention in HD is only possible if genetic diagnosis is made at the disease onset or when mild symptoms manifest. Growing evidence and understanding of HD pathomechanism has led researchers to new therapeutic targets. Here, in this article we will talk about the multimodal treatment strategies and recent advances made in this field which can be used to target the HD pathogenesis at its most proximal level.

Mitochondrial and lysosomal dysfunction accounts for a large group of inherited metabolic disorders most of which are due to a dysfunctional mitochondrial respiratory chain (MRC) leading to deficient energy production and defects in phagocytosis in endosomal-lysosomal pathway respectively. MRC function depends on the coordinated expression of both nuclear (nDNA) and mitochondrial (mtDNA) genomes. Thus, mitochondrial diseases can be caused by genetic defects in either the mitochondrial or the nuclear genome, or in the cross-talk between the two. The mitochondrial DNA depletion syndromes (MDSs) are a clinically heterogeneous group of disorders with an autosomal recessive pattern of inheritance that have onset in infancy or early childhood and are characterized by a reduced number of copies of mtDNA in affected tissues and organs. In this review article, we summarized the spectrum of mtDNA depletion disorders along with minor learning of lysosomal storage diseases. This current article offers a perspective on the role of genetics in medical practice and how this role may evolve over the next several years.