High burden of neurological disease in the older general population: results from the Canadian Longitudinal Study on Aging.

BACKGROUND AND PURPOSE: Our objective was to study the association between the presence of a neurological disease and the comorbidity burden as well as healthcare utilization (HCU). METHODS: Using baseline data from the Canadian Longitudinal Study on Aging (CLSA), we examined the burden of five neurological conditions. The CLSA is a population-based study of approximately 50 000 individuals, aged 45-85 years at baseline. We used multivariable Poisson regression to identify correlates of comorbidity burden and HCU. RESULTS: The lifetime prevalence of five neurological diseases is presented: epilepsy, Parkinson's disease/parkinsonism, stroke/transient ischaemic attack, multiple sclerosis and migraine. We found the somatic and psychiatric comorbidity burden to be higher in those individuals with a neurological disease (an 18-45% mean increase in the number of chronic conditions) as compared with the comparison group without a neurological disease, except for Parkinson's disease/parkinsonism. The presence of a neurological disease was associated with only a modest increase in the probability of visiting a general practitioner but was associated with a greatly increased probability of visiting a medical specialist (up to 68% more likely) or an emergency department (up to 79% more likely) and an overnight hospitalization (up to 108% more likely). CONCLUSIONS: We found striking associations between our neurological diseases and increased comorbidity burdens and HCU. These findings are important for informing public policy planning as well as driving avenues for future research. The present study established the CLSA as an important research platform for the study of neurological conditions in an aging general population.

Improving the quality of systematic reviews of neurological conditions: an assessment of current practice and the development and validation of six new search strategies.

BACKGROUND AND PURPOSE: Our aim was to study the quality of the literature search strategies used in recent systematic reviews and to develop and assess the diagnostic accuracy of six new search strategies (i.e. hedges). METHODS: Six neurological conditions were studied: migraine, stroke, dementia, epileptic seizures, Parkinson's disease and multiple sclerosis. Two reviewers independently assessed the quality of the search strategies used in systematic reviews published in 2015-2016. Complex hedges pertaining to the six conditions for use in Ovid MEDLINE were developed. Their diagnostic accuracy was compared to simple, single-term keyword searches. RESULTS: Almost 60% of quality criteria for the overall literature search strategy used in 182 systematic reviews were not respected. Over 30% of search strategies relied on a single keyword to identify the neurological condition. The sensitivities of our complex hedges amongst 10 311 articles were between 83% and 95%, significantly higher than the simple keyword searches (as low as 48%). The specificities were greater than 97%. CONCLUSIONS: There is great room for improvement in the search strategies used in systematic reviews of neurological conditions. Complex hedges were developed and validated to improve the accuracy of such searches. It is expected that this will lead to higher quality systematic reviews and meta-analyses.

Managing anti-epileptic drug treatment in adult patients with intellectual disability: a serious conundrum.

BACKGROUND AND PURPOSE: About a quarter of people with epilepsy have intellectual disability (ID). This group has communication issues, premature mortality, more treatment resistance, difficulties in making informed choices and greater risks of physical and mental health comorbidities. There is no specific prescribing guidance for this large and vulnerable group. The literature on prescribing for epilepsy in this group was reviewed, in particular examining how antiepileptic drugs (AEDs) work regarding their side effect profiles, effects on specific epilepsy syndromes associated with ID and their individual strengths and weaknesses based on the nature and degree of ID. METHOD: This is a narrative review for which a comprehensive search was conducted to identify evidence for prescribing commonly used AEDs to people with ID including genetic syndromes specifically associated with epilepsy. RESULTS: A detailed analysis of the results has highlighted the urgent requirement for suitable and reliable evidence in AED prescribing amongst adults with epilepsy and ID as no studies taking account of the response to AEDs of the ID populations based on the WHO Diagnostic and Statistical Manual of Mental Disorders criteria of clinical severity of ID were identified. CONCLUSION: There is a significant shortfall in suitably powered studies to provide sufficient evidence for safe prescribing of AEDs to people with ID.

The diagnostic accuracy of routine electroencephalography after a first unprovoked seizure.

The clinical utility of routine electroencephalography (EEG) after a first unprovoked seizure remains uncertain. Its diagnostic accuracy in identifying adults and children with new onset epilepsy was examined. A systematic review and meta-analysis of studies examining individuals who underwent routine EEG after a first unprovoked seizure and were followed for seizure recurrence for at least 1 year was performed. A 'positive' test was defined by the presence of epileptiform discharges (ED). Pooled sensitivity and specificity estimates were calculated using a bivariate random effects regression model. In all, 3096 records were reviewed, from which 15 studies were extracted with a total of 1799 participants. Amongst adult studies, the sensitivity and specificity (95% confidence interval) of routine EEG were 17.3% (7.9, 33.8) and 94.7% (73.7, 99.1), respectively. Amongst child studies, the pooled sensitivity and specificity were 57.8% (49.7, 65.6) and 69.6% (57.5, 79.5), respectively. Based upon our positive likelihood ratios, and assuming a pre-test probability of 50%, an adult with ED on routine EEG after a first unprovoked seizure has a 77% probability of having a second seizure, whilst a child with similar findings has a 66% probability. Further studies are required to examine the impact of patient characteristics and EEG features on the diagnostic accuracy of routine EEG for new onset epilepsy.

The comorbid relationship between migraine and epilepsy: a systematic review and meta-analysis.

A number of studies have suggested a pathophysiologic link between migraine and epilepsy. Our aim was to examine the relative lifetime prevalence of migraine in people with epilepsy (PWE) as well that of epilepsy in migraineurs. We carried out a systematic review, searching five electronic databases, specified bibliographies and conference abstracts in order to identify population-based studies that measured the lifetime co-prevalence of migraine and epilepsy. Two reviewers independently screened all titles and abstracts, carried out a risk of bias assessment and extracted the data. Meta-analyses were carried out using random effects models. Of the 3640 abstracts and titles screened, we identified 10 eligible studies encompassing a total of 1,548,967 subjects. Few of the studies used validated case ascertainment tools and there were inconsistent attempts to control for confounding. There was an overall 52% increase in the prevalence of migraine among PWE versus those without epilepsy [PR: 1.52 (95% CI: 1.29, 1.79)]. There was an overall 79% increase in the prevalence of epilepsy among migraineurs versus those without migraine [PR: 1.79 (95% CI: 1.43, 2.25)]. Subgroup analyses revealed that the method of ascertaining the epilepsy or migraine status of subjects was an important source of inter-study heterogeneity. Additional high quality primary studies are required, ones that use validated and accurate methods of case ascertainment as well as control for potential confounders.