The verbal fluency index: Dutch normative data for cognitive testing in ALS

Objective: Executive dysfunction occurs in 30-50% of amyotrophic lateral sclerosis (ALS) patients and is most frequently assessed with the verbal fluency test. The verbal fluency index (VFI) has been developed to correct for slowness of speech in ALS, and reflects the average thinking time per word. However, its use as a marker of cognitive impairment is hindered by the absence of valid norm scores. Therefore, we provide normative data for the VFI. Methods: Dutch volunteers were demographically matched to the Dutch ALS population and completed the verbal fluency index (one-minute and three-minute spoken letter fluency). Multiple stepwise linear regression was performed to assess the influence of demographic variables, past medical history and medication use. Results: 273 volunteers participated in this study. Educational level was negatively correlated to one-minute and three-minute VFI performance (r = -0.3 and r = -0.4, p < 0.001, respectively). No correlations for age, gender, medication and past medical history were found. A formula for standardized z-scores, corrected for educational level, for the one-minute and three-minute VFI was calculated. Conclusions: We provide Dutch normative data for the spoken verbal fluency index, which can be used internationally, but validation in other languages is recommended. The findings illustrate the importance of valid disease-specific norm scores for time-dependent cognitive tests in ALS

Long-term air pollution exposure and amyotrophic lateral sclerosis in Netherlands: A population-based case–control study

BACKGROUND: Recently, there has been increasing evidence that exposure to air pollution is linked to neurodegenerative diseases, but little is known about the association with amyotrophic lateral sclerosis (ALS). OBJECTIVES: We investigated the association between long-term exposure to air pollution and risk of developing ALS. METHODS: A population-based case–control study was conducted in Netherlands from 1 January 2006 to 1 January 2013. Data from 917 ALS patients and 2,662 controls were analyzed. Annual mean air pollution concentrations were assessed by land use regression (LUR) models developed as part of the European Study of Cohorts for Air Pollution Effects (ESCAPE). Exposure estimates included nitrogen oxides (NO2, NOx), particulate matter (PM) with diameters of <2.5 μm (PM2.5), <10 μm (PM10), between 10 μm and 2.5 μm (PMcoarse), and PM2.5 absorbance. We performed conditional logistic regression analysis using two different multivariate models (model 1 adjusted for age, gender, education, smoking status, alcohol use, body mass index, and socioeconomic status; model 2 additionally adjusted for urbanization degree). RESULTS: Risk of ALS was significantly increased for individuals in the upper exposure quartile of PM2:5 absorbance [OR = 1.67; 95% confidence interval (CI): 1.27, 2.18], NO2 (OR = 1.74; 95% CI: 1.32, 2.30), and NOx concentrations (OR = 1.38; 95% CI: 1.07, 1.77). These results, except for NOx, remained significant after adjusting additionally for urbanization degree. CONCLUSIONS: Based on a large population-based case–control study, we report evidence for the association between long-term exposure to traffic-related air pollution and increased susceptibility to ALS. Our findings further support the necessity for regulatory public health interventions to combat air pollution levels and provide additional insight into the potential pathophysiology of ALS

Effect of Presymptomatic Body Mass Index and Consumption of Fat and Alcohol on Amyotrophic Lateral Sclerosis

Because dietary intake may influence pathophysiologic mechanisms in sporadic amyotrophic lateral sclerosis (ALS), the association between premorbid dietary intake and the risk of sporadic ALS will provide insight into which mechanisms are possibly involved in ALS pathophogenesis. To systematically determine the association between premorbid dietary intake and the risk of sporadic ALS. A population-based case-control study was conducted in a general community setting in the Netherlands from January 1, 2006, to September 30, 2011. Analysis was conducted April 1, 2013, to November 15, 2014. All patients with a new diagnosis of possible, probable (laboratory supported), or definite ALS according to the revised El Escorial criteria were included and multiple sources were used to ensure complete case ascertainment. Of 986 eligible patients, 674 gave informed consent and returned a complete questionnaire; 2093 controls randomly selected from the general practitioners' registers and frequency matched to the patients for sex and age were included. We studied the premorbid intake of nutrients in association with the risk of ALS by using a 199-item food frequency questionnaire adjusted for confounding factors and corrected for multiple comparisons while minimizing recall bias. Presymptomatic total daily energy intake in patients, reported as mean (SD), was significantly higher compared with controls (2258 [730] vs 2119 [619] kcal/day; P  < .01), and presymptomatic body mass index (calculated as weight in kilograms divided by height in meters squared) was significantly lower in patients (25.7 [4.0] vs 26.0 [3.7]; P = .02). With values reported as odds ratio (95% CI), higher premorbid intake of total fat (1.14; 1.07-1.23; P  < .001), saturated fat (1.43; 1.25-1.64; P  < .001), trans-fatty acids (1.03; 1.01-1.05; P  < .001), and cholesterol (1.08; 1.05-1.12; P  < .001) was associated with an increased risk of ALS; higher intake of alcohol (0.91; 0.84-0.99; P = .03) was associated with a decreased risk of ALS. These associations were independent of total energy intake, age, sex, body mass index, educational level, smoking, and lifetime physical activity. No significant associations between dietary intake and survival were found. The combination of independent positive associations of a low premorbid body mass index and a high fat intake together with prior evidence from ALS mouse models transgenic for SOD1 and earlier reports on premorbid body mass index support a role for increased resting energy expenditure before clinical onset of AL

Brain morphologic changes in asymptomatic C9orf72 repeat expansion carriers

Objective: To investigate possible effects of the C9orf72 repeat expansion before disease onset, we assessed brain morphology in asymptomatic carriers. Methods: Aiming to diminish the effects of genetic variation between subjects, apart from the C9orf72 repeat expansion, 16 carriers of the repeat expansion were compared with 23 noncarriers from the same large family with a history of amyotrophic lateral sclerosis (ALS). Cortical thickness, subcortical volumes, and white matter connectivity, as assessed from high-resolution T1-weighted and diffusion-weighted MRIs, were evaluated. For comparison, we included 14 C9orf72 carriers with ALS and 28 healthy, unrelated controls. Results: We found temporal, parietal, and occipital regions to be thinner (p , 0.05) and the left caudate and putamen to be smaller (p , 0.05) in asymptomatic carriers compared with noncarriers. Cortical thinning of the primary motor cortex and decreased connectivity of white matter pathways (global, corticospinal tract, and corpus callosum) were observed in patients with C9orf72-associated ALS, but not in asymptomatic carriers. Conclusions: Asymptomatic C9orf72 carriers show cortical and subcortical differences compared with noncarriers from the same family, possibly effects of the C9orf72 repeat expansion on the brain. Of note, changes in the primary motor regions and motor-related tracts were found exclusively in patients with ALS, indicating that such motor changes may be a disease phenomenon

Lifetime physical activity and the risk of amyotrophic lateral sclerosis

It has been hypothesised that physical activity is a risk factor for developing amyotrophic lateral sclerosis (ALS), fuelled by observations that professional soccer players and Gulf War veterans are at increased risk. In a population based study, we determined the relation between physical activity and risk of sporadic ALS, using an objective approach for assessing physical activity. 636 sporadic ALS patients and 2166 controls, both population based, completed a semistructured questionnaire on lifetime history of occupations, sports and hobbies. To objectively compare the energy cost of a lifetime history of occupational and leisure time physical activities and to reduce recall bias, metabolic equivalent scores were assigned to each activity based on the Compendium of Physical Activities. ALS patients had significantly higher levels of leisure time physical activity compared with controls (OR 1.08, 95% CI 1.02 to 1.14, p=0.008). No significant difference was found between patients and controls in the level of vigorous physical activities, including marathons and triathlons, or in occupational activity. Cumulative measures of physical activity in quartiles did not show a dose-response relationship. An increased risk of ALS with higher levels of leisure time physical activity was found in the present study. The lack of association with occupational physical activity and the absence of a dose-response relationship strengthen the hypothesis that not increased physical activity per se but rather a genetic profile or lifestyle promoting physical fitness increases ALS susceptibilit

Parkinson's Disease Case Ascertainment in the EPIC Cohort : The NeuroEPIC4PD Study

BACKGROUND/AIMS: Large epidemiological prospective studies represent an important opportunity for investigating risk factors for rare diseases such as Parkinson's disease (PD). Here we describe the procedures we used for ascertaining PD cases in the EPIC (European Prospective Investigation into Cancer and Nutrition) study. METHODS: The following three-phase procedure was used: (1) elaboration of a NeuroEPIC4PD template for clinical data collection, (2) identification of all potential PD cases via record linkage and (3) validation of the diagnosis through clinical record revision, in a population of 220,494 subjects recruited in 7 European countries. All cases were labelled with the NeuroEPIC4PD diagnoses of 'definite', 'very likely', 'probable', or 'possible' PD. RESULTS: A total of 881 PD cases were identified, with over 2,741,780 person-years of follow-up (199 definite, 275 very likely, 146 probable, and 261 possible). Of these, 734 were incident cases. The mean age at diagnosis was 67.9 years (SD 9.2) and 458 patients (52.0%) were men. Bradykinesia was the most frequent presenting motor sign (76.5%). Tremor-dominant and akinetic rigid forms of PD were the most common types of PD. A total of 289 patients (32.8%) were dead at the time of the last follow-up. CONCLUSIONS: This exercise proved that it is feasible to ascertain PD in large population-based cohort studies and offers a potential framework to be replicated in similar studies

H63D polymorphism in HFE is not associated with amyotrophic lateral sclerosis

The H63D polymorphism in HFE has frequently been associated with susceptibility to amyotrophic lateral sclerosis (ALS). Regarding the role of HFE in iron homeostasis, iron accumulation is considered an important process in ALS. Furthermore, novel therapeutic strategies are being developed targeting this process. Evidence for this genetic association is, however, limited to several small studies. For this reason we studied the H63D polymorphism in a large European cohort including 3962 ALS patients and 5072 control subjects from 7 countries. After meta-analysis of previous studies and current findings we conclude that the H63D polymorphism in HFE is not associated with susceptibility to ALS, age at disease onset, or survival.status: publishe