Summary Background Spinocerebellar ataxias (SCAs) are autosomal, dominantly inherited, fully penetrant neurodegenerative diseases. Our aim was to study the preclinical stage of the most common SCAs: ...SCA1, SCA2, SCA3, and SCA6. Methods Between Sept 13, 2008, and Dec 1, 2011, offspring or siblings of patients with SCA1, SCA2, SCA3, or SCA6 were enrolled into a prospective, longitudinal observational study at 14 European centres. To be eligible for inclusion in our study, individuals had to have no ataxia and be aged 18–50 years if directly related to individuals with SCA1, SCA2, or SCA3, or 35–70 years if directly related to individuals with SCA6. We did anonymous genetic testing to identify mutation carriers. We assessed participants with clinical scales, questionnaires, and performance-based coordination tests. In eight of the 14 centres, participants underwent MRI. We analysed relations between outcome variables and time from onset (defined as the difference between present age and estimated age at ataxia onset). This study is registered with ClinicalTrials.gov , number NCT01037777. Findings 276 participants met inclusion criteria and agreed to participate, of whom 12 (4%) were excluded from final analysis because DNA samples were missing or genotyping failed. Estimated time from onset was −9 years (IQR −13 to −6) in 50 carriers of the SCA1 mutation, −12 years (–15 to −9) in 31 SCA2 mutation carriers, −8 years (–11 to −6) in 26 SCA3 mutation carriers, and −18 years (–22 to −16) in 16 SCA6 mutation carriers. Compared with non-carriers of each mutation, SCA1 mutation carriers had higher median scores on the scale for the assessment and rating of ataxia (SARA; 0·5 IQR 0–1·0 vs 0 0–0; p=0·0052), as did SCA2 mutation carriers (0·5 0–2·0 vs 0 0–0·5; p=0·0037). SCA2 mutation carriers had lower SCA functional index scores than did non-carriers (–0·43 –0·91 to −0·07 vs 0·09 –0·30 to 0·56; p=0·0007). SCA2 mutation carriers had worse composite cerebellar functional scores than did their non-carrier counterparts (0·915 0·861–0·959 vs 0·849 0·764–0·886; p=0·0039). All other differences between carriers and non-carriers were non-significant. In SCA1 and SCA2 mutation carriers, SARA scores were increased in participants who were closer to the estimated age at onset (SCA1: r =0·36, p=0·0112; SCA2: r =0·50, p=0·0038). 83 individuals (30%) underwent MRI. Voxel-based morphometry showed grey-matter loss in the brainstem and cerebellum in SCA1 and SCA2 mutation carriers, and normalised brainstem volume was lower in SCA2 mutation carriers (median 0·015, range 0·012–0·016) than in non-carriers (0·019, 0·017–0·021; p=0·0107). Interpretation Preclinical SCA1 and SCA2 mutation carriers seem to have mild coordination deficits and abnormalities in the brain that are more common in carriers who are closer to the estimated onset of ataxia. Individuals in this early disease stage could be targeted in future preventive trials. Funding ERA-Net E-Rare and Polish Ministry of Science and Higher Education.
Summary Background Spinocerebellar ataxias are dominantly inherited neurodegenerative diseases. As potential treatments for these diseases are being developed, precise knowledge of their natural ...history is needed. We aimed to study the long-term disease progression of the most common spinocerebellar ataxias: SCA1, SCA2, SCA3, and SCA6. Furthermore, we aimed to establish the order and occurrence of non-ataxia symptoms, and identify predictors of disease progression. Methods In this longitudinal cohort study (EUROSCA), we enrolled men and women with positive genetic testing for SCA1, SCA2, SCA3, or SCA6 and with progressive, otherwise unexplained ataxia who were aged 18 years or older from 17 ataxia referral centres in ten European countries. Patients were seen every year for 3 years, and at irregular intervals thereafter. The primary outcome was the scale for the assessment and rating of ataxia (SARA), and the inventory of non-ataxia signs (INAS). We used linear mixed models to analyse progression. To account for dropouts, we applied a pattern-mixture model. This study is registered with ClinicalTrials.gov , number NCT02440763. Findings Between July 1, 2005, and Aug 31, 2006, 526 patients with SCA1, SCA2, SCA3, or SCA6 were enrolled. We analysed data for 462 patients with at least one follow-up visit. Median observation time was 49 months (IQR 35–72). SARA progression data were best fitted with a linear model in all genotypes. Annual SARA score increase was 2·11 (SE 0·12) in patients with SCA1, 1·49 (0·07) in patients with SCA2, 1·56 (0·08) in patients with SCA3, and 0·80 (0·09) in patients with SCA6. The increase of the number of non-ataxia signs reached a plateau in SCA1, SCA2, and SCA3. In patients with SCA6, the number of non-ataxia symptoms increased linearly, but more slowly than in patients with SCA1, SCA2, and SCA3 (p<0·0001). Factors that were associated with faster progression of the SARA score were short duration of follow-up (p=0·0179), older age at inclusion (0.04 SE 0·02 per additional year; p=0·0476), and longer repeat expansions (0·06 SE 0·02 per additional repeat unit; p=0·0128) in SCA1, short duration of follow-up (p<0·0001), lower age at onset (–0·02 SE 0·01 per additional year; p=0·0014), and lower baseline SARA score (–0·02 SE 0·01 per additional SARA point; p=0·0083) in SCA2, and lower baseline SARA score (–0·03 SE 0·01 per additional SARA point; p=0·0195) in SCA6. In SCA3, we did not identify factors that affected progression of the SARA score. Interpretation Our study provides quantitative data on the progression of the most common spinocerebellar ataxias based on a follow-up period that exceeds those of previous studies. Our data could prove useful for sample size calculation and patient stratification in interventional trials. Funding EU FP6 (EUROSCA), German Ministry of Education and Research (BMBF; GeneMove), Polish Ministry of Science, EU FP7 (NEUROMICS).
•The clinical heterogeneity of hereditary spastic paraplegia is unpredictable.•Perception of spasticity is modified by intrinsic and extrinsic factors.•Participants report that stressful situations ...exacerbate spasticity.•Physiotherapy most effectively reduces lower limb spasticity.•Physiotherapy and physical activity should be performed at least 3 times a week.
Background: Phenotypic variability is a consistent finding in neurogenetics and therefore applicable to hereditary spastic paraparesis. Identifying reasons for this variability is a challenge. We hypothesized that, in addition to genetic modifiers, extrinsic factors influence variability.
Objectives: Our aim was to describe the clinical variability in hereditary spastic paraparesis from the person's perspective. Our goals were to identify individual and environmental factors that influence muscle tone disorders and derive interventions which could improve spasticity.
Methods: This study was based on self-assessments with questions on nominal and ordinal scales completed by participants with hereditary spastic paraparesis. A questionnaire was completed either in-person in the clinic or electronically via lay organization websites.
Results: Among the 325 responders, most had SPG4/SPAST (n = 182, 56%) with a mean age at onset of 31.7 (SD 16.7) years and a mean disease duration of 23 (SD 13.6) years at the time of participation. The 2 factors identified as improving spasticity for > 50% of the responders were physiotherapy (193/325, 59%), and superficial warming (172/308, 55%). Half of the responders (n = 164, 50%) performed physical activity at least once a month and up to once a week. Participants who reported physiotherapy as effective were significantly more satisfied with ≥ 3 sessions per week. Psychologically stressful situations (246/319, 77%) and cold temperatures (202/319, 63%) exacerbated spasticity for most participants.
Conclusion: Participants perceived that physiotherapy reduced spasticity and that the impact of physiotherapy on spasticity was much greater than other medical interventions. Therefore, people should be encouraged to practice physical activity at least 3 times per week. This study reported participants’ opinions: in hereditary spastic paraparesis only functional treatments exist, therefore the participant's expertise is of particular importance.
Summary Background TRACK-HD is a multinational prospective observational study of Huntington's disease (HD) that examines clinical and biological findings of disease progression in individuals with ...premanifest HD (preHD) and early-stage HD. We aimed to describe phenotypic changes in these participants over 36 months and identify baseline predictors of progression. Methods Individuals without HD but carrying the mutant huntingtin gene (classed as preHD-A if ≥10·8 years and preHD-B if <10·8 years from predicted onset), participants with early HD (classed as HD1 if they had a total functional capacity score of 11–13 and HD2 if they had a score of 7–10), and healthy control individuals were assessed at four study sites in the Netherlands, the UK, France, and Canada. We measured 36-month change for 3T MRI, clinical, cognitive, quantitative motor, and neuropsychiatric assessments and examined their prognostic value. We also assessed the relation between disease progression and the combined effect of CAG repeat length and age. All participants were analysed according to their baseline subgroups. Longitudinal results were analysed using a combination of repeated-measure weighted least squares models and, when examining risk of new diagnosis, survival analysis. Findings At baseline, 366 participants were enrolled between Jan 17, and Aug 26, 2008, and of these 298 completed 36-month follow-up: 97 controls, 58 participants with preHD-A, 46 with preHD-B, 66 with HD1, and 31 with HD2. In the preHD-B group, several quantitative motor and cognitive tasks showed significantly increased rates of decline at 36 months, compared with controls, whereas few had at 24 months. Of the cognitive measures, the symbol digit modality test was especially sensitive (adjusted mean loss 4·11 points 95% CI 1·49–6·73 greater than controls; p=0·003). Among psychiatric indicators, apathy ratings specifically showed significant increases (0·34 points 95% CI 0·02–0·66 greater than controls; p=0·038). There was little evidence of reliable change in non-imaging measures in the preHD-A group, with the exception of the speeded tapping inter-tap interval (0·01 s 95% CI 0·01–0·02 longer than controls; p=0·0001). Several baseline imaging, quantitative motor, and cognitive measures had prognostic value, independent of age and CAG repeat length, for predicting subsequent clinical diagnosis in preHD. Of these, grey-matter volume and inter-tap interval were particularly sensitive (p=0·013 and 0·002, respectively). Longitudinal change in these two measures was also greater in participants with preHD who received a diagnosis of HD during the study compared with those who did not, after controlling for CAG repeat length and age-related risk (p=0·006 and 0·0003, respectively). In early HD, imaging, quantitative motor, and cognitive measures were predictive of decline in total functional capacity and tracked longitudinal change; also, neuropsychiatric changes consistent with frontostriatal pathological abnormalities were associated with this loss of functional capacity (problem behaviours assessment composite behaviour score p<0·0001). Age and CAG repeat length explained variance in longitudinal change of multimodal measures, with the effect more prominent in preHD. Interpretation We have shown changes in several outcome measures in individuals with preHD over 36 months. These findings further our understanding of HD progression and have implications for clinical trial design. Funding CHDI Foundation.
Summary Background Blood biomarkers of neuronal damage could facilitate clinical management of and therapeutic development for Huntington's disease. We investigated whether neurofilament light ...protein NfL (also known as NF-L) in blood is a potential prognostic marker of neurodegeneration in patients with Huntington's disease. Methods We did a retrospective analysis of healthy controls and carriers of CAG expansion mutations in HTT participating in the 3-year international TRACK-HD study. We studied associations between NfL concentrations in plasma and clinical and MRI neuroimaging findings, namely cognitive function, motor function, and brain volume (global and regional). We used random effects models to analyse cross-sectional associations at each study visit and to assess changes from baseline, with and without adjustment for age and CAG repeat count. In an independent London-based cohort of 37 participants (23 HTT mutation carriers and 14 controls), we further assessed whether concentrations of NfL in plasma correlated with those in CSF. Findings Baseline and follow-up plasma samples were available from 97 controls and 201 individuals carrying HTT mutations. Mean concentrations of NfL in plasma at baseline were significantly higher in HTT mutation carriers than in controls (3·63 SD 0·54 log pg/mL vs 2·68 0·52 log pg/mL, p<0·0001) and the difference increased from one disease stage to the next. At any given timepoint, NfL concentrations in plasma correlated with clinical and MRI findings. In longitudinal analyses, baseline NfL concentration in plasma also correlated significantly with subsequent decline in cognition (symbol-digit modality test r =–0·374, p<0·0001; Stroop word reading r =–0·248, p=0·0033), total functional capacity ( r =–0·289, p=0·0264), and brain atrophy (caudate r =0·178, p=0·0087; whole-brain r =0·602, p<0·0001; grey matter r =0·518, p<0·0001; white matter r =0·588, p<0·0001; and ventricular expansion r =–0·589, p<0·0001). All changes except Stroop word reading and total functional capacity remained significant after adjustment for age and CAG repeat count. In 104 individuals with premanifest Huntington's disease, NfL concentration in plasma at baseline was associated with subsequent clinical onset during the 3-year follow-up period (hazard ratio 3·29 per log pg/mL, 95% CI 1·48–7·34, p=0·0036). Concentrations of NfL in CSF and plasma were correlated in mutation carriers ( r =0·868, p<0·0001). Interpretation NfL in plasma shows promise as a potential prognostic blood biomarker of disease onset and progression in Huntington's disease. Funding Medical Research Council, GlaxoSmithKline, CHDI Foundation, Swedish Research Council, European Research Council, Wallenberg Foundation, and Wolfson Foundation.
Summary Background TRACK-HD is a prospective observational study of Huntington's disease (HD) that examines disease progression in premanifest individuals carrying the mutant HTT gene and those with ...early stage disease. We report 12-month longitudinal changes, building on baseline findings. Methods We did a 12-month follow-up of patients recruited from the four TRACK-HD study sites in Canada, France, the Netherlands, and the UK. Participants were premanifest individuals (preHD) carrying the mutant HTT gene, patients with early HD, and controls matched by age and sex with the combined preHD and early HD groups. Data were collected by use of 3T MRI and clinical, cognitive, quantitative motor, oculomotor, and neuropsychiatric measures. Statistical analysis assessed annualised change with the use of linear regression models to estimate differences between groups. Findings 116 preHD individuals, 114 early HD patients, and 115 people in the control group completed follow-up. Four preHD individuals, nine early HD patients, and eight people in the control group did not complete the follow-up. A further nine participants, who completed follow-up assessments, were unable to undergo MRI. After adjustment for demographics, annualised rates of generalised and regional brain atrophy were higher in preHD and early HD groups than in controls. Whole-brain atrophy rates were 0·20% (95% CI 0·05–0·34; p=0·0071) per year higher in preHD participants and 0·60% (0·44–0·76; p<0·0001) in early HD patients, and caudate atrophy rates were 1·37% (0·99–1·75; p<0·0001) per year higher in preHD and 2·86% (2·34–3·39; p<0·0001) in early HD. Voxel-based morphometry revealed grey-matter and white-matter atrophy, even in subjects furthest from predicted disease onset. Quantitative imaging showed statistically significant associations with disease burden, an indicator of disease pathology, and total functional capacity, a widely-used clinical measure of disease severity. Relative to controls, decline in cognition and quantitative motor function was detectable in both pre- and early HD, as was deterioration in oculomotor function in early HD. Interpretation Quantitative imaging showed the greatest differentiation across the spectrum of disease and functional measures of decline were sensitive in early HD, with cognitive and quantitative motor impairment also detectable in preHD. We show longitudinal change over 12 months in generalised and regional brain volume, cognition, and quantitative motor tasks in individuals many years from predicted disease onset and show the feasibility of obtaining quantifiable endpoints for future trials. Funding CHDI/HighQ Foundation Inc.
Summary Background TRACK-HD is a prospective observational biomarker study in premanifest and early Huntington's disease (HD). In this report we define a battery of potential outcome measures for ...therapeutic trials. Methods We assessed longitudinal data collected at baseline, 12 months, and 24 months at sites in Leiden (Netherlands), London (UK), Paris (France), and Vancouver (Canada). Participants were individuals without HD but carrying the mutant HTT gene (ie, premanifest HD), patients with early HD, and healthy control individuals matched by age and sex to the combined HD groups. Data were collected with 3T MRI, clinical, cognitive, quantitative motor, oculomotor, and neuropsychiatric assessments. We estimated adjusted, between-group differences in rates of change in these measures and concomitant longitudinal effect sizes. Findings Longitudinal data were available for 116 control individuals, 117 premanifest gene carriers, and 116 participants with early HD. Significantly greater progressive grey-matter, white-matter, whole-brain, and regional atrophy was recorded in the premanifest and early HD groups than in the control group. Effect sizes for atrophy rates between participants with early HD and controls were largest in the caudate (2·04, 95% CI 1·68 to 2·48) and white matter (1·70, 1·40 to 2·08). Functional, quantitative motor, and cognitive measures deteriorated to a greater extent in the early HD group than in controls, with the largest effect size in the symbol digit modality test (1·00, 0·67 to 1·27). In the early HD group, changes in structural imaging and various cognitive and quantitative motor scores were associated with worsening total motor score (TMS) and total functional capacity (TFC). In the premanifest group, despite significant declines in regional and overall brain volumes, few functional variables showed significant 24 month change compared with controls; TMS, emotion recognition, and speeded tapping were exceptions. Premanifest individuals with progression, predefined as an increase in TMS score of 5 points or more, any TFC decline, or a new diagnostic confidence score of 4, exhibited higher rates of brain atrophy and deterioration on some quantitative motor tasks compared with other premanifest participants. Interpretation On the basis of longitudinal effect size, we recommend several objective outcome measures for clinical trials in participants with early HD. Hypothetical treatment effects defined by slower longitudinal changes in these measures would be detectable over a realistic timescale with practical sample sizes. The restricted 24 month cognitive or motor decline in the premanifest sample illustrates the greater challenge in trial design for this group. Funding CHDI/HighQ Foundation Inc.
Summary Background Mutations in LRRK2 , the gene that encodes leucine-rich repeat kinase 2, are a cause of Parkinson's disease (PD). The International LRRK2 Consortium was established to answer three ...key clinical questions: can LRRK2 -associated PD be distinguished from idiopathic PD; which mutations in LRRK2 are pathogenic; and what is the age-specific cumulative risk of PD for individuals who inherit or are at risk of inheriting a deleterious mutation in LRRK2 ? Methods Researchers from 21 centres across the world collaborated on this study. The frequency of the common LRRK2 Gly2019Ser mutation was estimated on the basis of data from 24 populations worldwide, and the penetrance of the mutation was defined in 1045 people with mutations in LRRK2 from 133 families. The LRRK2 phenotype was defined on the basis of 59 motor and non-motor symptoms in 356 patients with LRRK2 -associated PD and compared with the symptoms of 543 patients with pathologically proven idiopathic PD. Findings Six mutations met the consortium's criteria for being proven pathogenic. The frequency of the common LRRK2 Gly2019Ser mutation was 1% of patients with sporadic PD and 4% of patients with hereditary PD; the frequency was highest in the middle east and higher in southern Europe than in northern Europe. The risk of PD for a person who inherits the LRRK2 Gly2019Ser mutation was 28% at age 59 years, 51% at 69 years, and 74% at 79 years. The motor symptoms (eg, disease severity, rate of progression, occurrence of falls, and dyskinesia) and non-motor symptoms (eg, cognition and olfaction) of LRRK2 -associated PD were more benign than those of idiopathic PD. Interpretation Mutations in LRRK2 are a clinically relevant cause of PD that merit testing in patients with hereditary PD and in subgroups of patients with PD. However, this knowledge should be applied with caution in the diagnosis and counselling of patients. Funding UK Medical Research Council; UK Parkinson's Disease Society; UK Brain Research Trust; Internationaal Parkinson Fonds; Volkswagen Foundation; National Institutes of Health: National Institute of Neurological Disorders and Stroke and National Institute of Aging; Udall Parkinson's Disease Centre of Excellence; Pacific Alzheimer Research Foundation Centre; Italian Telethon Foundation; Fondazione Grigioni per il Morbo di Parkinson; Michael J Fox Foundation for Parkinson's Research; Safra Global Genetics Consortium; US Department of Veterans Affairs; French Agence Nationale de la Recherche.
Summary Background The European Friedreich’s Ataxia Consortium for Translational Studies (EFACTS) is a prospective international registry investigating the natural history of Friedreich’s ataxia. We ...used data from EFACTS to assess disease progression and the predictive value of disease-related factors on progression, and estimated sample sizes for interventional randomised clinical trials. Methods We enrolled patients with genetically confirmed Friedreich’s ataxia from 11 European study sites in Austria, Belgium, France, Germany, Italy, Spain, and the UK. Patients were seen at three visits—baseline, 1 year, and 2 years. Our primary endpoint was the Scale for the Assessment and Rating of Ataxia (SARA). Secondary outcomes were the Inventory of Non-Ataxia Signs (INAS), the Spinocerebellar Ataxia Functional Index (SCAFI), phonemic verbal fluency (PVF), and the quality of life measures activities of daily living (ADL) and EQ-5D-3L index. We estimated the yearly progression for each outcome with linear mixed-effect modelling. This study is registered with ClinicalTrials.gov , number NCT02069509 , and follow-up assessments and recruitment of new patients are ongoing. Findings Between Sept 15, 2010, and Nov 21, 2013, we enrolled 605 patients with Friedreich’s ataxia. 546 patients (90%) contributed data with at least one follow-up visit. The progression rate on SARA was 0·77 points per year (SE 0·06) in the overall cohort. Deterioration in SARA was associated with younger age of onset (–0·02 points per year 0·01 per year of age) and lower SARA baseline scores (–0·07 points per year 0·01 per baseline point). Patients with more than 353 GAA repeats on the shorter allele of the FXN locus had a higher SARA progression rate (0·09 points per year 0·02 per additional 100 repeats) than did patients with fewer than 353 repeats. Annual worsening was 0·10 points per year (0·03) for INAS, −0·04 points per year (0·01) for SCAFI, 0·93 points per year (0·06) for ADL, and −0·02 points per year (0·004) for EQ-5D-3L. PVF performance improved by 0·99 words per year (0·14). To detect a 50% reduction in SARA progression at 80% power, 548 patients would be needed in a 1 year clinical trial and 184 would be needed for a 2 year trial. Interpretation Our results show that SARA is a suitable clinical rating scale to detect deterioration of ataxia symptoms over time; ADL is an appropriate measure to monitor changes in daily self-care activities; and younger age at disease onset is a major predictor for faster disease progression. The results of the EFACTS longitudinal analysis provide suitable outcome measures and sample size calculations for the design of upcoming clinical trials of Friedreich’s ataxia. Funding European Commission.
Summary Background Friedreich's ataxia is a rare autosomal recessive neurodegenerative disorder. Here we report cross-sectional baseline data to establish the biological and clinical characteristics ...for a prospective, international, European Friedreich's ataxia database registry. Methods Within the European Friedreich's Ataxia Consortium for Translational Studies (EFACTS) framework, we assessed a cohort of patients with genetically confirmed Friedreich's ataxia. The primary outcome measure was the Scale for the Assessment and Rating of Ataxia (SARA) and secondary outcome measures were the Inventory of Non-Ataxia Signs (INAS), the performance-based coordination test Spinocerebellar Ataxia Functional Index (SCAFI), the neurocognitive phonemic verbal fluency test, and two quality-of-life measures: the activities of daily living (ADL) part of the Friedreich's Ataxia Rating Scale and EQ-5D. The Friedreich's ataxia cohort was subdivided into three groups: early disease onset (≤14 years), intermediate onset (15–24 years), and late onset (≥25 years), which were compared for clinical characteristics and outcome measures. We used linear regression analysis to estimate the annual decline of clinical outcome measures based on disease duration. This study is registered with ClinicalTrials.gov , number NCT02069509. Findings We enrolled 592 patients with genetically confirmed Friedreich's ataxia between Sept 15, 2010, and April 30, 2013, at 11 sites in seven European countries. Age of disease onset was inversely correlated with the number of GAA repeats in the frataxin ( FXN ) gene: every 100 GAA repeats on the smaller repeat allele was associated with a 2·3 year (SE 0·2) earlier onset. Regression analyses showed significant estimated annual worsening of SARA (regression coefficient 0·86 points SE 0·05, INAS (0·14 points 0·01), SCAFI Z scores (−0·09 0·01), verbal fluency (−0·34 words 0·07), and ADL (0·64 points 0·04) during the first 25 years of disease; the regression slope for health-related quality-of-life state from EQ-5D was not significant (−0·33 points 0·18). For SARA, the predicted annual rate of worsening was significantly higher in early-onset patients (n=354; 1·04 points 0·13) and intermediate-onset patients (n=137; 1·17 points 0·22) than in late-onset patients (n=100; 0·56 points 0·10). Interpretation The results of this cross-sectional baseline analysis of the EFACTS cohort suggest that earlier disease onset is associated with larger numbers of GAA repeats and more rapid disease progression. The differential estimated progression of ataxia symptoms related to age of onset have implications for the design of clinical trials in Friedreich's ataxia, for which SARA might be the most suitable measure to monitor disease progression. Funding European Commission.
PDF
