Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Which Environmental Factor Is Correlated with Long-Term Multiple Sclerosis Incidence Trends: Ultraviolet B Radiation or Geomagnetic Disturbances?

Background. Insufficient received ultraviolet B radiation (UV) is regarded as the main environmental risk factor (RF) for MS in vitamin D deficiency hypothesis. Nevertheless, geomagnetic disturbance (GMD) has also been proposed as a potential trigger for MS in GMD hypothesis. The aim of this study was to investigate which of these mentioned RF is correlated with long-term ultradecadal MS incidence. Methods. After a systematic search, long-term incidence reports of the United Kingdom (UK), Denmark, Tayside County, Nordland County, the Orkney, and Shetland Islands were selected for this retrospective time-series study. Possible lead-lag relationships between MS incidence, GMD, and UV were evaluated by cross-correlation analysis. Results. Significant positive correlations between GMD and MS incidence were seen in Tayside County (at lag of 2 years: rS = 0.38), Denmark (peak correlation at lag of 2 years: rS = 0.53), and UK (at lag of 1 year: rS = 0.50). We found a positive correlation between received UV and MS incidences in the Nordland at lag of 1 year (rS = 0.49). Conclusion. This study found significant positive correlations between alterations in GMD with alterations in long-term MS incidence in three out of six studied locations and supports the GMD hypothesis. The observed significant correlation between MS and UV is positive; hence it is not supportive for UV related vitamin D deficiency hypothesis

The Effect of Clofibrate on Neonatal Hyperbilirubinemia in Uncomplicated Jaundice

Objective: Clofibrate has been used for several years as a hypolipidemic drug. Our aim was to study the effect of Clofibrate on neonatal hyperbilirubinemia in uncomplicated jaundice. Material & Methods: This clinical trial study has been conducted on 90 normal term neonates who were admitted for uncomplicated jaundice in 17th-Shahrivar Children's Hospital of Guilan University of Medical Sciences from September 2005 to January 2006. The data included: age, sex, total and direct serum bilirubin, weight and duration of hospitalization. All data were analyzed by using statistical methods. Findings: All 90 infants enrolled in our study had received phototherapy. The infants were divided into Clofibrate group (G1) consisting of 26 boys (57.8%) and 19 girls (42.2%) and Control group with 24 boys (53.3%) and 21 girls (46.7%) (G2). There were no statistically overt differences between the two groups regarding sex distribution, age, weight and total serum bilirubin level at admission. Mean values for total bilirubin of serum in Clofibrate group 12, 24, 36, and 48 hours after admission were significantly lower than those for Control group (P<0.00l). The mean time needed for phototherapy in Clofibrate group (38.8) (20-48h) was significantly shorter than that in control group (68.7) (36-96h) (P<0.00l). Conclusion: Clofibrate is effective and probably a safe drug for neonatal hyperbilirubinemia that can decrease the time needed for phototherapy and hospitalization, although further studies with a more precise and longer follow up is needed for proving its safety to be used routinely in the treatment of neonatal hyperbilirubinemia

Tapering Oral Steroid Treatment After IV Methylprednisolone Pulse Therapy in Demyelinating Optic Neuritis

Background: Optic neuritis is an inflammation of the optic nerve. Because of importance of vision for human, management of optic neuritis is an important issue in neurology. Objectives: This study aimed at assessing the effect of oral steroid treatment after intravenous (IV) methylprednisolone therapy on demyelinating optic neuritis. Materials & Methods: 60 Patients with first episode of acute demyelinating optic neuritis who referred to a neurology clinic in an academic hospital in south-west of Iran in 2015-2016 included in this randomized double-blind clinical trial study (No: IRCT2015102724735N1). They were divided into two groups with (A) and without (B) tapering oral steroid treatment after IV methylprednisolone. Visual acuity and color vision were measured before treatment, before oral tapering, 1 and 3 months after treatment. Independent t-test in SPSS software version 20 was used to analyze the data. P<0.05 was considered as the level of significance. Results: Visual acuity in two groups did not have any significant difference in any time point of assessment (P>0.05).Frequency of color vision abnormality in groups A and B were at baseline (53.3% vs. 56.6%) (P=0.796), before oral tapering (43.3% vs. 30%, P=0.284), 1 month after treatment (23.3% vs. 30%, P=0.559), 3 months after treatment (0% vs. 23%, P=0.011).  Conclusion: Oral steroid treatment after IV methylprednisolone pulse therapy improves color vision after 3 months in patients with demyelinating optic neuritis but has no effect on visual acuity

Higher latitude is significantly associated with an earlier age of disease onset in multiple sclerosis

Background Age at onset (AAO) in multiple sclerosis (MS) is an important marker of disease severity and may have prognostic significance. Understanding what factors can influence AAO may shed light on the aetiology of this complex disease, and have applications in the diagnostic process

Prognostic indicators in pediatric clinically isolated syndrome.

To assess prognostic factors for a second clinical attack and a first disability-worsening event in pediatric clinically isolated syndrome (pCIS) suggestive of multiple sclerosis (MS) patients

Long-term disability trajectories in primary progressive MS patients: A latent class growth analysis

BACKGROUND: Several natural history studies on primary progressive multiple sclerosis (PPMS) patients detected a consistent heterogeneity in the rate of disability accumulation. OBJECTIVES: To identify subgroups of PPMS patients with similar longitudinal trajectories of Expanded Disability Status Scale (EDSS) over time. METHODS: All PPMS patients collected within the MSBase registry, who had their first EDSS assessment within 5 years from onset, were included in the analysis. Longitudinal EDSS scores were modeled by a latent class mixed model (LCMM), using a nonlinear function of time from onset. LCMM is an advanced statistical approach that models heterogeneity between patients by classifying them into unobserved groups showing similar characteristics. RESULTS: A total of 853 PPMS (51.7% females) from 24 countries with a mean age at onset of 42.4 years (standard deviation (SD): 10.8 years), a median baseline EDSS of 4 (interquartile range (IQR): 2.5-5.5), and 2.4 years of disease duration (SD: 1.5 years) were included. LCMM detected three different subgroups of patients with a mild ( n = 143; 16.8%), moderate ( n = 378; 44.3%), or severe ( n = 332; 38.9%) disability trajectory. The probability of reaching EDSS 6 at 10 years was 0%, 46.4%, and 81.9% respectively. CONCLUSION: Applying an LCMM modeling approach to long-term EDSS data, it is possible to identify groups of PPMS patients with different prognosis