Determinants of neurological disease: Synthesis of systematic reviews.

Systematic reviews were conducted to identify risk factors associated with the onset and progression of 14 neurological conditions, prioritized as a component of the National Population Health Study of Neurological Conditions. These systematic reviews provided a basis for evaluating the weight of evidence of evidence for risk factors for the onset and progression of the 14 individual neurological conditions considered. A number of risk factors associated with an increased risk of onset for more than one condition, including exposure to pesticides (associated with an increased risk of AD, amyotrophic lateral sclerosis, brain tumours, and PD; smoking (AD, MS); and infection (MS, Tourette syndrome). Coffee and tea intake was associated with a decreased risk of onset of both dystonia and PD. Further understanding of the etiology of priority neurological conditions will be helpful in focusing future research initiatives and in the development of interventions to reduce the burden associated with neurological conditions in Canada and internationally.

A systematic review of risk factors associated with muscular dystrophies.

The purpose of this study was to systematically review, assess, and prioritize factors (including biological, socioeconomic, environmental, psychosocial, comorbid, and genetic) for the onset and natural progression of Muscular Dystrophy. Comprehensive review of current literature of these factors was carried out in order to provide a basis for policy makers to identify appropriate measures to mitigate the burden of disease in Canada. A three-stage approach to searching for relevant studies was conducted in multiple databases. Using variations of MeSH terms and keywords, Systematic reviews or meta-analyses published in English or French that meet the inclusion criteria were first identified, then searched for relevant observational studies. Two independent reviewers screened abstracts, then qualifying articles, conducted quality assessment, and finally extracted relevant data using the application, DistillerSR. No existing systematic reviews, meta-analyses, or non-genetic observational studies were identified that met the inclusion criteria. A number of existing systematic reviews and observational studies focused on pharmacological or therapeutic interventions, which was beyond the scope of this study. Four genetic observational studies were identified that focused on aspects of disease progression of Duchenne and Becker Muscular Dystrophy. While this systematic review found that certain genetic polymorphisms and mutations may be a factor for Duchenne or Becker Muscular Dystrophy disease progression, further investigation into other genetic factors and environmental factors is still warranted. Much of the current literature focuses on these Muscular Dystrophies, however, other types of Muscular Dystrophy and their associated risk factors have yet to be extensively studied.

Onset factors in cerebral palsy: A systematic review.

Studies have noted several factors associated with the occurrence of Cerebral Palsy (CP), yet considerable uncertainty remains about modifiable factors related to disease onset. A systematic review was performed to identify existing systematic reviews and primary studies pertaining to targeted factors associated with the onset of CP. The following databases were searched: MEDLINE, MEDLINE In Process, EMBASE, PsycINFO, Scopus, Web of Science, Cochrane Database of Systematic Reviews, CINHAL, ProQuest Dissertations & Theses, Huge Navigator, AARP Ageline. Variations of MeSH and keyword search terms were used. Critical appraisal was conducted on selected articles. Data extraction targeted reported factors, risk estimates, and 95% confidence intervals (CI). Findings identified two systematic reviews and three meta- analyses, as well as 83 studies of case control, cohort, and cross-sectional methodological designs. Selected studies indicated that lower gestational age was associated with the onset of CP. Medical diagnoses for the mother, in particular chorioamnionitis, was found to be positively associated with onset of CP. Preeclampsia was reported to be either inconclusive or positively associated with CP onset. Low birth weight predominantly indicated a positive association with the onset of CP, while male gender showed mixed findings. The combination of male gender with pre-term or low birth weight was also found to be positively associated with CP. Evidence was identified in the literature pertaining to specific factors relating to the onset of CP, in particular showing positive associations with lower gestational age and low birth weight.

Onset and progression factors in Parkinson's disease: A systematic review.

Current research has identified several factors thought to be associated with the onset and progression of Parkinson's Disease (PD); however, whether certain factors contribute to or are protective against PD remains unclear. As such, a systematic search of the literature was performed using variations of MeSH and keyword search terms to identify and summarize systematic reviews and primary studies pertaining to factors associated with the onset and progression of PD. Factors referred to both traditional risk factors and prodromal markers. The following databases were searched: MEDLINE, MEDLINE In-Process, EMBASE, PsycINFO, Scopus, Web of Science, Cochrane Database of Systematic Reviews, Cumulative Index to Nursing and Allied Health Literature (CINAHL), ProQuest Dissertations & Theses, AARP AgeLine, and PDGene. A quality assessment of included systematic reviews was completed using the validated Assessment of the Methodological Quality of Systematic Reviews (AMSTAR) tool. Data extraction targeted reported factors, risk estimates, and 95% confidence intervals (CI). Findings identified 11 systematic reviews of sufficient quality reporting factors for PD onset, and no systematic reviews reporting factors for PD progression. In addition, 93 primary articles were identified, of which, 89 articles addressed factors related to PD onset and 4 articles addressed factors related to the PD progression. Pesticide exposure, rural living, well-water drinking, and farming occupation were consistently found to be positively associated with the onset of PD. Moreover, family history and polymorphisms to key genes were also found to be positively associated with the onset of PD. Conversely, coffee consumption, cigarette smoking, and some polymorphisms were consistently found to be negatively associated with the onset of PD. Urate was the only identified factor linked to the progression of PD; it was mostly found to be negatively associated with PD. In sum, the evidence was systematically found and summarized in the literature pertaining to factors related to the onset and progression of PD.