Chantal Depondt

Scale for the assessment and rating of ataxia: development of a new clinical scale.

Objective: To develop a reliable and valid clinical scale measuring the severity of ataxia. Methods: The authors devised the Scale for the Assessment and Rating of Ataxia (SARA) and tested it in two trials of 167 and 119 patients with spinocerebellar ataxia. Results: The mean time to administer SARA in patients was 14.2 ± 7.5 minutes (range 5 to 40). Interrater reliability was high, with an intraclass coefficient (ICC) of 0.98. Test-retest reliability was high with an ICC of 0.90. Internal consistency was high as indicated by Cronbachs α of 0.94. Factorial analysis revealed that the rating results were determined by a single factor. SARA ratings showed a linear relation to global assessments using a visual analogue scale, suggesting linearity of the scale (p < 0.0001, r2 = 0.98). SARA score increased with the disease stage (p < 0.001) and was closely correlated with the Barthel Index (r = −0.80, p < 0.001) and part IV (functional assessment) of the Unified Huntingtons Disease Rating Scale (UHDRS-IV) (r = −0.89, p < 0.0001), whereas it had only a weak correlation with disease duration (r = 0.34, p < 0.0002) Conclusions: The Scale for the Assessment and Rating of Ataxia is a reliable and valid measure of ataxia, making it an appropriate primary outcome measure for clinical trials.

Spinocerebellar ataxia types 1, 2, 3, and 6: disease severity and nonataxia symptoms.

Objective: To identify factors that determine disease severity and clinical phenotype of the most common spinocerebellar ataxias (SCAs), we studied 526 patients with SCA1, SCA2, SCA3. or SCA6. Methods: To measure the severity of ataxia we used the Scale for the Assessment and Rating of Ataxia (SARA). In addition, nonataxia symptoms were assessed with the Inventory of Non-Ataxia Symptoms (INAS). The INAS count denotes the number of nonataxia symptoms in each patient. Results: An analysis of covariance with SARA score as dependent variable and repeat lengths of the expanded and normal allele, age at onset, and disease duration as independent variables led to multivariate models that explained 60.4% of the SARA score variance in SCA1, 45.4% in SCA2, 46.8% in SCA3, and 33.7% in SCA6. In SCA1, SCA2, and SCA3, SARA was mainly determined by repeat length of the expanded allele, age at onset, and disease duration. The only factors determining the SARA score in SCA6 were age at onset and disease duration. The INAS count was 5.0 ± 2.3 in SCA1, 4.6 ± 2.2 in SCA2, 5.2 ± 2.5 in SCA3, and 2.0 ± 1.7 in SCA6. In SCA1, SCA2, and SCA3, SARA score and disease duration were the strongest predictors of the INAS count. In SCA6, only age at onset and disease duration had an effect on the INAS count. Conclusions: Our study suggests that spinocerebellar ataxia (SCA) 1, SCA2, and SCA3 share a number of common biologic properties, whereas SCA6 is distinct in that its phenotype is more determined by age than by disease-related factors.

Responsiveness of different rating instruments in spinocerebellar ataxia patients.

Objective: To determine the longitudinal metric properties of recently developed clinical assessment tools in spinocerebellar ataxia (SCA). Methods: A subset of 171 patients from the EUROSCA natural history study cohort (43 SCA1, 61 SCA2, 37 SCA3, and 30 SCA6) were examined after 1 year of follow-up. Score changes and effect size indices were calculated for clinical scales (Scale for the Assessment and Rating of Ataxia [SARA], Inventory of Non-Ataxia Symptoms [INAS]), functional tests (SCA Functional Index [SCAFI] and components), and a patient-based scale for subjective health status (EQ-5D visual analogue scale [EQVAS]). Responsiveness was determined in relation to the patients global impression (PGI) of change and reproducibility described as retest reliability for the stable groups and smallest detectable change. Results: Within the 1-year follow-up period, SARA, INAS, and SCAFI but not EQVAS indicated worsening in the whole group and in the groups with subjective (PGI) worsening. SCAFI and its 9-hole pegboard (9HPT) component also deteriorated in the stable groups. Standardized response means were highest for 9HPT (−0.67), SARA (0.50), and SCAFI (−0.48) with accordingly lower sample size estimates of 143, 250, or 275 per group for a 2-arm interventional trial that aims to reduce disease progression by 50%. SARA and EQVAS performed best to distinguish groups classified as worse by PGI. All scales except EQVAS reached the criterion for retest reliability. Conclusion: While both the Scale for the Assessment and Rating of Ataxia and the SCA Functional Index (SCAFI) (and its 9-hole pegboard component) had favorable measurement precision, the clinical relevance of SCAFI and 9-hole pegboard score changes warrants further exploration. The EQ-5D visual analogue scale proved insufficient for longitudinal assessment, but validly reflected patients impression of change.

SCA Functional Index A useful compound performance measure for spinocerebellar ataxia

Objective: To evaluate the usefulness of functional measures in patients with spinocerebellar ataxia (SCA). Methods: We assessed three functional measures—8 m walking time (8MW), 9-hole peg test (9HPT), and PATA repetition rate—in 412 patients with autosomal dominant SCA (genotypes 1, 2, 3, and 6) in a multicenter trial. Results: While PATA rate was normally distributed (mean/median 21.7/20.5 per 10 s), the performance times for 8MW (mean/median 10.8/7.5 s) or 9HPT (mean/median 47.2/35.0 s in dominant, 52.2/37.9 s in nondominant hand) were markedly skewed. Possible learning effects were small and likely clinically irrelevant. A composite functional index (SCAFI) was formed after appropriate transformation of subtest results. The Z-scores of each subtest correlated well with the Scale for the Assessment and Rating of Ataxia (SARA), the Unified Huntingtons disease Rating Scale functional assessment, and disease duration. Correlations for SCAFI with each of these parameters were stronger (Pearson r = −0.441 to −0.869) than for each subtest alone. Furthermore, SCAFI showed a linear decline over the whole range of disease severity, while 9HPT and 8MW had floor effects with respect to SARA. Analysis of possible confounders showed no effect of genotype or study site and only minor effects of age for 8MW. Conclusion: The proposed functional measures and their composite SCAFI have favorable properties to assess patients with spinocerebellar ataxia.

Early symptoms in spinocerebellar ataxia type 1, 2, 3, and 6.

Onset of genetically determined neurodegenerative diseases is difficult to specify because of their insidious and slowly progressive nature. This is especially true for spinocerebellar ataxia (SCA) because of varying affection of many parts of the nervous system and huge variability of symptoms. We investigated early symptoms in 287 patients with SCA1, SCA2, SCA3, or SCA6 and calculated the influence of CAG repeat length on age of onset depending on (1) the definition of disease onset, (2) people defining onset, and (3) duration of symptoms. Gait difficulty was the initial symptom in two‐thirds of patients. Double vision, dysarthria, impaired hand writing, and episodic vertigo preceded ataxia in 4% of patients, respectively. Frequency of other early symptoms did not differ from controls and was regarded unspecific. Data about disease onset varied between patients and relatives for 1 year or more in 44% of cases. Influence of repeat length on age of onset was maximum when onset was defined as beginning of permanent gait disturbance and cases with symptoms for more than 10 years were excluded. Under these conditions, CAG repeat length determined 64% of onset variability in SCA1, 67% in SCA2, 46% in SCA3, and 41% in SCA6 demonstrating substantial influence of nonrepeat factors on disease onset in all SCA subtypes. Identification of these factors is of interest as potential targets for disease modifying compounds. In this respect, recognition of early symptoms that develop before onset of ataxia is mandatory to determine the shift from presymptomatic to affected status in SCA.

Novel locus on chromosome 12q22-q23.3 responsible for familial temporal lobe epilepsy associated with febrile seizures

Idiopathic epilepsies have a genetic basis and are characterised by the absence of an overt underlying neurological abnormality. Most idiopathic epilepsies are complex diseases with considerable clinical and genetic heterogeneity and an unclear inheritance pattern because of genetic and environmental factors. Families in which the disease segregates as an autosomal dominant trait with reduced disease penetrance have been identified occasionally. In some of these families, a single gene defect was identified as the cause of epilepsy. To date, mutations in 13 genes have been identified for distinct epilepsy types. Most genes encode subunits of ion channels.1,2 In addition, the gene remains to be identified for 21 mapped loci for epilepsy, which highlights the genetic heterogeneity of the idiopathic epilepsy syndromes.3,4nnFamilial temporal lobe epilepsy (MIM 608096) was first described by Berkovic et al . and was recognised as a distinct epileptic syndrome by the International League Against Epilepsy.5 It is defined by familial occurrence of simple partial seizures, complex partial seizures, and secondarily generalised seizures of temporal lobe origin.6 Two genetically distinct autosomal dominant familial temporal lobe epilepsy syndromes have been reported. Autosomal dominant lateral temporal lobe epilepsy (MIM 600512), or autosomal dominant partial epilepsy with auditory features, was described first by Ottman et al . ,7 and recently, mutations in the leucine rich glioma inactivated 1 ( LGI1 ) gene on chromosome 10q24 were identified.8,9 Auras that present as auditory and visual hallucinations are a clinical hallmark of this syndrome. The other variant of familial temporal lobe epilepsy is characterised clinically by onset in teenage years or early adulthood, absence of antecedent factors, low frequency of deja vu, and a usually good prognosis. This variant, which still can be heterogeneous genetically, is not mapped yet. In a large family with febrile seizures …

Biological and clinical characteristics of the European Friedreich's Ataxia Consortium for Translational Studies (EFACTS) cohort: a cross-sectional analysis of baseline data.

BACKGROUNDnFriedreichs 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 Friedreichs ataxia database registry.nnnMETHODSnWithin the European Friedreichs Ataxia Consortium for Translational Studies (EFACTS) framework, we assessed a cohort of patients with genetically confirmed Friedreichs 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 Friedreichs Ataxia Rating Scale and EQ-5D. The Friedreichs 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.nnnFINDINGSnWe enrolled 592 patients with genetically confirmed Friedreichs 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]).nnnINTERPRETATIONnThe 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 Friedreichs ataxia, for which SARA might be the most suitable measure to monitor disease progression.nnnFUNDINGnEuropean Commission.

Spinocerebellar Ataxia Types 1, 2, 3 and 6: the Clinical Spectrum of Ataxia and Morphometric Brainstem and Cerebellar Findings

To assess the clinical spectrum of ataxia and cerebellar oculomotor deficits in the most common spinocerebellar ataxias (SCAs), we analysed the baseline data of the EUROSCA natural history study, a multicentric cohort study of 526 patients with either spinocerebellar ataxia type 1, 2, 3 or 6. To quantify ataxia symptoms, we used the Scale for the Assessment and Rating of Ataxia (SARA). The presence of cerebellar oculomotor signs was assessed using the Inventory of Non-Ataxia Symptoms (INAS). In a subgroup of patients, in which magnetic resonance images (MRIs) were available, we correlated MRI morphometric measures with clinical signs on an exploratory basis. The SARA subscores posture and gait (items 1–3), speech (item 4) and the limb kinetic subscore (items 5–8) did not differ between the genotypes. The scores of SARA item 3 (sitting), 5 (finger chase) and 6 (nose–finger test) differed between the subtypes whereas the scores of the remaining items were not different. In SCA1, ataxia symptoms were correlated with brainstem atrophy and in SCA3 with both brainstem and cerebellar atrophy. Cerebellar oculomotor deficits were most frequent in SCA6 followed by SCA3, whereas these abnormalities were less frequent in SCA1 and SCA2. Our data suggest that vestibulocerebellar, spinocerebellar and pontocerebellar circuits in SCA1, SCA2, SCA3 and SCA6 are functionally impaired to almost the same degree, but at different anatomical levels. The seemingly low prevalence of cerebellar oculomotor deficits in SCA1 and SCA2 is most probably related to the defective saccadic system in these disorders.

Central role and mechanisms of β-cell dysfunction and death in friedreich ataxia-associated diabetes.

Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused in almost all cases by homozygosity for a GAA trinucleotide repeat expansion in the frataxin gene. Frataxin is a mitochondrial protein involved in iron homeostasis. FRDA patients have a high prevalence of diabetes, the pathogenesis of which is not known. We aimed to evaluate the relative contribution of insulin resistance and β‐cell failure and the pathogenic mechanisms involved in FRDA diabetes.

Depression comorbidity in spinocerebellar ataxia

This is a description of the prevalence and profile of depressive symptoms in dominant spinocerebellar ataxia (SCA). Depressive symptoms were assessed in a convenience sample of 526 genetically confirmed and clinically affected patients (117 SCA1, 163 SCA2, 139 SCA3, and 107 SCA6) using the Patient Health Questionnaire (PHQ). In addition, depressive status according to the examiner and the use of antidepressants was recorded. Depression self‐assessment was compared with an interview‐based psychiatric assessment in a subset of 26 patients. Depression prevalence estimates were 17.1% according to the PHQ algorithm and 15.4% when assessed clinically. The sensitivity of clinical impression compared with PHQ classification was low (0.35), whereas diagnostic accuracy of PHQ compared with psychiatric interview in the subset was high. Antidepressants were used by 17.7% of patients and in >10% of patients without current clinically relevant depressive symptoms. Depression profile in SCA did not differ from a sample of patients with major depressive disorder except for the movement‐related item. Neither depression prevalence nor use of antidepressants differed between genetic subtypes, with only sleep disturbance more common in SCA3. In a multivariate analysis, ataxia severity and female sex independently predicted depressive status in SCA. The PHQ algorithmic classification is appropriate for use in SCA but should stimulate further psychiatric evaluation if depression is indicated. Despite a higher risk for depression with more severe disease, the relation of depressive symptoms to SCA neurodegeneration remains to be shown.