Neurological, cardiological, and oculomotor progression in 104 patients with Friedreich ataxia during long-term follow-up

Therapeutic Biomarkers in Friedreich's Ataxia: a Systematic Review and Meta-analysis

Although a large array of biomarkers have been investigated in Friedreich's ataxia (FRDA) trials, the optimal biomarker for assessing disease progression or therapeutic benefit has yet to be identified. We searched PubMed, MEDLINE, and EMBASE databases up to June 2023 for any original study (with ≥ 5 participants and ≥ 2 months' follow-up) reporting the effect of therapeutic interventions on any clinical, cardiac, biochemical, patient-reported outcome measures, imaging, or neurophysiologic biomarker. We also explored the biomarkers' ability to detect subtle disease progression in untreated patients. The pooled standardized mean difference (SMD) was calculated using a random-effects model. The study's protocol was registered in PROSPERO (CRD42022319196). In total, 43 studies with 1409 FRDA patients were included in the qualitative synthesis. A statistically significant improvement was observed in Friedreich Ataxia Rating Scale scores [combining Friedreich Ataxia Rating Scale (FARS) and modified FARS (mFARS): SMD =  - 0.32 (- 0.62 to - 0.02)] following drugs that augment mitochondrial function in a sensitivity analysis. Left ventricular mass index (LVMI) was improved significantly [SMD =  - 0.34 (- 0.5 to - 0.18)] after 28.5 months of treatment with drugs that augment mitochondrial function. However, LVMI remained stable [SMD = 0.05 (- 0.3 to 0.41)] in untreated patients after 6-month follow-up. None of the remaining biomarkers changed significantly following any treatment intervention nor during the natural disease progression. Nevertheless, clinical implications of these results should be interpreted with caution because of low to very low quality of evidence. Further randomized controlled trials of at least 24 months' duration using a biomarker toolbox rather than a single biomarker are warranted.

Quantitative Oculomotor Assessment in Hereditary Ataxia: Systematic Review and Consensus by the Ataxia Global Initiative Working Group on Digital-motor Biomarkers

Oculomotor deficits are common in hereditary ataxia, but disproportionally neglected in clinical ataxia scales and as outcome measures for interventional trials. Quantitative assessment of oculomotor function has become increasingly available and thus applicable in multicenter trials and offers the opportunity to capture severity and progression of oculomotor impairment in a sensitive and reliable manner. In this consensus paper of the Ataxia Global Initiative Working Group On Digital Oculomotor Biomarkers, based on a systematic literature review, we propose harmonized methodology and measurement parameters for the quantitative assessment of oculomotor function in natural-history studies and clinical trials in hereditary ataxia. MEDLINE was searched for articles reporting on oculomotor/vestibular properties in ataxia patients and a study-tailored quality-assessment was performed. One-hundred-and-seventeen articles reporting on subjects with genetically confirmed (n=1134) or suspected hereditary ataxia (n=198), and degenerative ataxias with sporadic presentation (n=480) were included and subject to data extraction. Based on robust discrimination from controls, correlation with disease-severity, sensitivity to change, and feasibility in international multicenter settings as prerequisite for clinical trials, we prioritize a core-set of five eye-movement types: (i) pursuit eye movements, (ii) saccadic eye movements, (iii) fixation, (iv) eccentric gaze holding, and (v) rotational vestibulo-ocular reflex. We provide detailed guidelines for their acquisition, and recommendations on the quantitative parameters to extract. Limitations include low study quality, heterogeneity in patient populations, and lack of longitudinal studies. Standardization of quantitative oculomotor assessments will facilitate their implementation, interpretation, and validation in clinical trials, and ultimately advance our understanding of the evolution of oculomotor network dysfunction in hereditary ataxias.

Predictors of Survival in Friedreich's Ataxia: A Prospective Cohort Study

BACKGROUND

Friedreich's ataxia (FA) is a rare multisystemic disorder which can cause premature death.

OBJECTIVES

To investigate predictors of survival in FA.

METHODS

Within a prospective registry established by the European Friedreich's Ataxia Consortium for Translational Studies (EFACTS; ClinicalTrials.gov identifier NCT02069509) we enrolled genetically confirmed FA patients at 11 tertiary centers and followed them in yearly intervals. We investigated overall survival applying the Kaplan-Meier method, life tables, and log-rank test. We explored prognostic factors applying Cox proportional hazards regression and subsequently built a risk score which was assessed for discrimination and calibration performance.

RESULTS

Between September 2010 and March 2017, we enrolled 631 FA patients. Median age at inclusion was 31 (range, 6-76) years. Until December 2022, 44 patients died and 119 terminated the study for other reasons. The 10-year cumulative survival rate was 87%. In a multivariable analysis, the disability stage (hazard ratio [HR] 1.51, 95% CI 1.08-2.12, P = 0.02), history of arrhythmic disorder (HR 2.93, 95% CI 1.34-6.39, P = 0.007), and diabetes mellitus (HR 2.31, 95% CI 1.05-5.10, P = 0.04) were independent predictors of survival. GAA repeat lengths did not improve the survival model. A risk score built on the previously described factors plus the presence of left ventricular systolic dysfunction at echocardiography enabled identification of four trajectories to prognosticate up to 10-year survival (log-rank test P < 0.001).

CONCLUSIONS

Arrhythmias, progressive neurological disability, and diabetes mellitus influence the overall survival in FA. We built a survival prognostic score which identifies patients meriting closer surveillance and who may benefit from early invasive cardiac monitoring and therapy. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Quantitative Oculomotor Assessment in Hereditary Ataxia: Discriminatory Power, Correlation with Severity Measures, and Recommended Parameters for Specific Genotypes

Characterizing bedside oculomotor deficits is a critical factor in defining the clinical presentation of hereditary ataxias. Quantitative assessments are increasingly available and have significant advantages, including comparability over time, reduced examiner dependency, and sensitivity to subtle changes. To delineate the potential of quantitative oculomotor assessments as digital-motor outcome measures for clinical trials in ataxia, we searched MEDLINE for articles reporting on quantitative eye movement recordings in genetically confirmed or suspected hereditary ataxias, asking which paradigms are most promising for capturing disease progression and treatment response. Eighty-nine manuscripts identified reported on 1541 patients, including spinocerebellar ataxias (SCA2, n = 421), SCA3 (n = 268), SCA6 (n = 117), other SCAs (n = 97), Friedreich ataxia (FRDA, n = 178), Niemann-Pick disease type C (NPC, n = 57), and ataxia-telangiectasia (n = 85) as largest cohorts. Whereas most studies reported discriminatory power of oculomotor assessments in diagnostics, few explored their value for monitoring genotype-specific disease progression (n = 2; SCA2) or treatment response (n = 8; SCA2, FRDA, NPC, ataxia-telangiectasia, episodic-ataxia 4). Oculomotor parameters correlated with disease severity measures including clinical scores (n = 18 studies (SARA: n = 9)), chronological measures (e.g., age, disease duration, time-to-symptom onset; n = 17), genetic stratification (n = 9), and imaging measures of atrophy (n = 5). Recurrent correlations across many ataxias (SCA2/3/17, FRDA, NPC) suggest saccadic eye movements as potentially generic quantitative oculomotor outcome. Recommendation of other paradigms was limited by the scarcity of cross-validating correlations, except saccadic intrusions (FRDA), pursuit eye movements (SCA17), and quantitative head-impulse testing (SCA3/6). This work aids in understanding the current knowledge of quantitative oculomotor parameters in hereditary ataxias, and identifies gaps for validation as potential trial outcome measures in specific ataxia genotypes.

Phenotype and management of neurologic intronic repeat disorders (NIRDs)

During recent years an increasing number of neurologic disorders due to expanded tri-, tetra-, penta-, or hexa-nucleotide repeat motifs in introns of various genes have been described (neurologic intronic repeat disorders (NIRDs)). The repeat may be pathogenic in the heterozygous or homozygous form. Repeat lengths vary considerably and can be stable or unstable during transmission to the next generation. The most well-known NIRDs are Friedreich ataxia, spinocerebellar ataxia types-10, -31, and -36, CANVAS, C9Orf72 familial amyotrophic lateral sclerosis (fALS), and myotonic dystrophy-2 (MD2). Phenotypically, NIRDs manifest as mono-organ (e.g. spinocerebellar ataxia type 31) or multi-organ disease (e.g. Friedreich ataxia, myotonic dystrophy-2). A number of other more rare NIRDs have been recently detected. This review aims at summarising and discussing previous findings and recent advances concerning the etiology, pathophysiology, clinical presentation, and therapeutic management of the most common NIRDs.

Cardiovascular Research in Friedreich Ataxia: Unmet Needs and Opportunities

Friedreich Ataxia (FRDA) is an autosomal recessive disease in which a mitochondrial protein, frataxin, is severely decreased in its expression. In addition to progressive ataxia, patients with FRDA often develop a cardiomyopathy that can be hypertrophic. This cardiomyopathy is unlike the sarcomeric hypertrophic cardiomyopathies in that the hypertrophy is associated with massive mitochondrial proliferation within the cardiomyocyte rather than contractile protein overexpression. This is associated with atrial arrhythmias, apoptosis, and fibrosis over time, and patients often develop heart failure leading to premature death. The differences between this mitochondrial cardiomyopathy and the more common contractile protein hypertrophic cardiomyopathies can be a source of misunderstanding in the management of these patients. Although imaging studies have revealed much about the structure and function of the heart in this disease, we still lack an understanding of many important clinical and fundamental molecular events that determine outcome of the heart in FRDA. This review will describe the current basic and clinical understanding of the FRDA heart, and most importantly, identify major gaps in our knowledge that represent new directions and opportunities for research.

Discovery of Therapeutics Targeting Oxidative Stress in Autosomal Recessive Cerebellar Ataxia: A Systematic Review

Autosomal recessive cerebellar ataxias (ARCAs) are a heterogeneous group of rare neurodegenerative inherited disorders. The resulting motor incoordination and progressive functional disabilities lead to reduced lifespan. There is currently no cure for ARCAs, likely attributed to the lack of understanding of the multifaceted roles of antioxidant defense and the underlying mechanisms. This systematic review aims to evaluate the extant literature on the current developments of therapeutic strategies that target oxidative stress for the management of ARCAs. We searched PubMed, Web of Science, and Science Direct Scopus for relevant peer-reviewed articles published from 1 January 2016 onwards. A total of 28 preclinical studies fulfilled the eligibility criteria for inclusion in this systematic review. We first evaluated the altered cellular processes, abnormal signaling cascades, and disrupted protein quality control underlying the pathogenesis of ARCA. We then examined the current potential therapeutic strategies for ARCAs, including aromatic, organic and pharmacological compounds, gene therapy, natural products, and nanotechnology, as well as their associated antioxidant pathways and modes of action. We then discussed their potential as antioxidant therapeutics for ARCAs, with the long-term view toward their possible translation to clinical practice. In conclusion, our current understanding is that these antioxidant therapies show promise in improving or halting the progression of ARCAs. Tailoring the therapies to specific disease stages could greatly facilitate the management of ARCAs.

Clinical evidence of interventions assessed in Friedreich ataxia: a systematic review

Objectives

The rare inherited autosomal recessive disease Friedreich ataxia (FA) causes progressive neurodegenerative changes and disability in patients. A systematic literature review (SLR) was carried out to understand and summarize the published efficacy and safety of therapeutic interventions in this disease.

Methods

Database searches were carried out in MEDLINE, Embase, and Cochrane by two independent reviewers. In addition, trial registries and conference proceedings were hand-searched.

Results

Thirty-two publications were deemed eligible according to PICOS criteria. Twenty-four publications detail randomized controlled trials. The most frequently identified therapeutic intervention was idebenone (n = 11), followed by recombinant erythropoietin (n = 6), omaveloxolone (n = 3), and amantadine hydrochloride (n = 2). Other therapeutic interventions were investigated in one publication: A0001, CoQ10, creatine, deferiprone, interferon-γ-1b, the L-carnitine levorotatory form of 5-hydroxytryptophan, luvadaxistat, resveratrol, RT001, and vatiquinone (EPI-743). These studies included patients from 8 to 73 years old, and disease duration varied from 4.7 to 19 years. Disease severity as per the mean GAA1 and GAA2 allele repeat length ranged from 350 to 930 and 620 to 987 nucleotides, respectively. Most frequently reported efficacy outcomes were the International Cooperative Ataxia Rating Scale (ICARS, n = 10), the Friedreich Ataxia Rating Scale (modified FARS and FARS-neuro, n = 12), the Scale for Assessment and Rating of Ataxia (SARA, n = 7), and the Activities of Daily Living scale (ADL, n = 8). Each of these assesses the severity of disability in FA patients. In many studies, patients with FA deteriorated according to these severity scales regardless of treatment, or inconclusive results were found. Generally, these therapeutic interventions were well-tolerated and safe. Serious adverse events were atrial fibrillation (n = 1), craniocerebral injury (n = 1), and ventricular tachycardia (n = 1).

Conclusion

Identified literature showed a considerable unmet need for therapeutic interventions that halt or slow the deteriorating nature of FA. Novel efficacious drugs should be investigated that aim to improve symptoms or slow disease progression.

Ectopic Burden via Holter Monitors in Friedreich Ataxia

BACKGROUND

Friedreich ataxia is the most commonly inherited ataxia; nearly 60% of deaths are cardiac in nature, with one in eight deaths due to arrhythmia. Additional or irregular heartbeats, measured as ectopy, can be quantified using portable heart rhythm monitoring. We sought to describe the ectopic burden in Friedreich ataxia.

METHODS

Using a natural history study of patients with Friedreich ataxia at a single center, we analyzed portable heart rhythm monitors (Holters). Ectopic burden was defined as the proportion of atrial or ventricular ectopic beats over total beats.

RESULTS

Of 456 patients, 131 had Holters. Sixty-eight (52.0%) were male, median age of symptom onset was 8.0 years (5.0 to 13.0, n = 111), median age at time of Holter was 17.3 years (interquartile range [IQR] 12.9 to 22.8, n = 129), and median duration of illness was 8.7 years (IQR 5.3 to 11.6, n = 110). Median GAA length on the shorter FXN allele was 706.0 (IQR 550.0 to 840.0, n = 112). Eight (7.8%, n = 103) had diminished cardiac function, and 74 (74.0%, n = 100) had ventricular hypertrophy. Ninety patients (83.0%) had atrial ectopy (supraventricular ectopy [SVE]): 85 (78.0%) with rare SVE (>0% to 5%) and five (5.0%) with frequent SVE (>10%). Twenty-five (19.0%) had supraventricular runs, and one (0.8%) had atrial fibrillation/flutter. Forty-five (41.0%) had ventricular ectopy (VE): 43 (39.0%) with rare VE (0% to 5%) and two (2.0%) with moderate VE (5% to 10%). Compared with patients with none and rare SVE, patients with frequent SVE had longer disease duration (18.3 versus 4.6 versus 9.0 years, P = 0.0005).

CONCLUSION

Patients with longer disease duration had higher rates of SVE. Heart rhythm monitoring may be considered for risk stratification; however, longitudinal analysis is needed.

Safety and efficacy of (+)-epicatechin in subjects with Friedreich's ataxia: A phase II, open-label, prospective study

BACKGROUND

(+)-Epicatechin (EPI) induces mitochondrial biogenesis and antioxidant metabolism in muscle fibers and neurons. We aimed to evaluate safety and efficacy of (+)-EPI in pediatric subjects with Friedreich's ataxia (FRDA).

METHODS

This was a phase II, open-label, baseline-controlled single-center trial including 10 participants ages 10 to 22 with confirmed FA diagnosis. (+)-EPI was administered orally at 75 mg/d for 24 weeks, with escalation to 150 mg/d at 12 weeks for subjects not showing improvement of neuromuscular, neurological or cardiac endpoints. Neurological endpoints were change from baseline in Friedreich's Ataxia Rating Scale (FARS) and 8-m timed walk. Cardiac endpoints were changes from baseline in left ventricular (LV) structure and function by cardiac magnetic resonance imaging (MRI) and echocardiogram, changes in cardiac electrophysiology, and changes in biomarkers for heart failure and hypertrophy.

RESULTS

Mean FARS/modified (m)FARS scores showed nonstatistically significant improvement by both group and individual analysis. FARS/mFARS scores improved in 5/9 subjects (56%), 8-m walk in 3/9 (33%), 9-peg hole test in 6/10 (60%). LV mass index by cardiac MRI was significantly reduced at 12 weeks (P = .045), and was improved in 7/10 (70%) subjects at 24 weeks. Mean LV ejection fraction was increased at 24 weeks (P = .008) compared to baseline. Mean maximal septal thickness by echocardiography was increased at 24 weeks (P = .031). There were no serious adverse events.

CONCLUSION

(+)-EPI was well tolerated over 24 weeks at up to 150 mg/d. Improvement was observed in cardiac structure and function in subset of subjects with FRDA without statistically significant improvement in primary neurological outcomes.

SYNOPSIS

A (+)-epicatechin showed improvement of cardiac function, nonsignificant reduction of FARS/mFARS scores, and sustained significant upregulation of muscle-regeneration biomarker follistatin.

A Cortical Substrate for Square-Wave Jerks in Progressive Supranuclear Palsy

Background and Purpose

Square-wave jerks (SWJs) are the most common saccadic intrusion in progressive supranuclear palsy (PSP), but their genesis is uncertain. We aimed to determine the characteristics of SWJs in PSP (the Richardson subtype) and Parkinson's disease (PD) and to map the brain structures responsible for abnormal SWJ parameters in PSP.

Methods

Eye movements in 12 patients with PSP, 12 patients with PD, and 12 age-matched healthy controls were recorded using an infrared corneal reflection device. The rate, mean amplitude, and velocity of SWJs were analyzed offline. Voxel-based morphometry using a 3-Tesla MRI scanner was performed to relate changes in brain volume to SWJ parameters.

Results

The SWJ rate was more than threefold higher in PSP patients than in both PD patients and controls (mean rates: 33.5, 10.3, and 4.3 SWJs per minute, respectively). The volumes of neither the midbrain nor other infratentorial brain regions were correlated with the SWJ rate. Instead, highly significant associations were found for atrophy in the superior, middle, and inferior temporal gyri in the PSP group.

Conclusions

SWJs in PSP are not mediated by midbrain atrophy. Instead, supratentorial cortical structures located mainly in the temporal lobe appear to be deeply involved in the generation of abnormally high SWJ rates in these patients. Known anatomical connections of the temporal lobe to the superior colliculus and the cerebellum might play a role in SWJ genesis.

Left ventricular structural and functional changes in Friedreich ataxia - Relationship with body size, sex, age and genetic severity

Introduction

Although a concentric pattern of left ventricular (LV) geometry appears to be common in Friedreich ataxia (FRDA), there is no accepted method for diagnosing LV abnormalities in FRDA, sex and body size have often not been taken into consideration, and it has not been clear whether children and adults should be classified using the same criteria. The aim of this study was to better define the LV geometric changes in FRDA with respect to sex, body size and subject age, and to investigate the relationship of LV changes with genetic severity, as assessed by GAA repeat length within the shorter allele of the FXN gene (GAA1).

Methods

Echocardiography was performed in 216 subjects (68 children, 148 adults), measurements were made at end-diastole of LV internal diameter (LVEDID), septal wall thickness (SWT), LV length (LVEDL) and LV volume (LVEDV), and calculations were made of relative wall thickness (RWT), LV mass and LV ejection fraction (LVEF).

Results

The most common LV abnormalities in both adults and children with FRDA were increases in RWT and age-normalized RWT. In adults with a normal LVEF, all LV variables other than RWT were larger in males independent of body surface area (BSA), and all LV variables other than SWT and RWT were positively correlated with BSA. After adjustment for sex and BSA, GAA1 was a positive correlate of SWT and RWT (but not of LV mass), and was an inverse correlate of LVEDID, LVEDL and LVEDV. In children with a normal LVEF, SWT, LV mass and LVEDL were larger in males than females after adjusting for BSA, and in combination with sex, BSA was a positive correlate of all the LV variables except SWT and RWT. In children there were no correlations of GAA1 with any of the LV variables.

Conclusion

In FRDA, increases in RWT and age-normalized RWT are the most frequent LV structural abnormalities, sex and body size are important determinants of most other LV structural variables in both children and adults, and increased genetic severity is associated with a smaller left ventricle and increased LV wall thickness in adults, but not associated with LV size or wall thickness in children.

Patient-reported outcomes in Friedreich's ataxia after withdrawal from idebenone

OBJECTIVES

Friedreich's ataxia is the most common inherited ataxia, and pathogenesis is known to involve mitochondrial oxidative stress. Idebenone is a potent antioxidant which has already been evaluated in several clinical trials in FRDA, with reports of symptomatic benefit but inconclusive objective results. Following patient consultation on design, we have completed a treatment-withdrawal study to establish whether patients could correctly determine their treatment allocation to placebo or idebenone. Our aim was to capture subjective experiences of symptoms such as fatigue, which can be difficult to measure with questionnaires or semi-quantitative scales, particularly in chronic, slowly progressive conditions.

MATERIALS AND METHODS

Patients taking idebenone for at least 12 months as part of the open-label MICONOS Extension Study were randomized to receive either placebo or idebenone continuation for 2-month treatment cycles. The primary endpoint was patient assessment of treatment assignment.

RESULTS

A total of 29 patients were randomized, forming the idebenone group (n = 16) and the placebo group (n = 13). No significant differences were detected between the idebenone and placebo groups on assessment of treatment assignment or early study withdrawal. A small but significant difference in ataxia rating scale scores was detected between treatment groups when considering ambulatory patients only.

CONCLUSIONS

This study provides no data to suggest that FRDA patients could correctly determine their treatment assignment over a 2-month period. We hope that this study design will help inform future trials so that patients' experiences of symptoms are more reliably measured.

Friedreich and dominant ataxias: quantitative differences in cerebellar dysfunction measurements

BACKGROUND

Sensitive outcome measures for clinical trials on cerebellar ataxias are lacking. Most cerebellar ataxias progress very slowly and quantitative measurements are required to evaluate cerebellar dysfunction.

METHODS

We evaluated two scales for rating cerebellar ataxias: the Composite Cerebellar Functional Severity (CCFS) Scale and Scale for the Assessment and Rating of Ataxia (SARA), in patients with spinocerebellar ataxia (SCA) and controls. We evaluated these scales for different diseases and investigated the factors governing the scores obtained. All patients were recruited prospectively.

RESULTS

There were 383 patients with Friedreich's ataxia (FRDA), 205 patients with SCA and 168 controls. In FRDA, 31% of the variance of cerebellar signs with the CCFS and 41% of that with SARA were explained by disease duration, age at onset and the shorter abnormal repeat in the FXN gene. Increases in CCFS and SARA scores per year were lower for FRDA than for SCA (CCFS index: 0.123±0.123 per year vs 0.163±0.179, P<0.001; SARA index: 1.5±1.2 vs 1.7±1.7, P<0.001), indicating slower cerebellar dysfunction indexes for FRDA than for SCA. Patients with SCA2 had higher CCFS scores than patients with SCA1 and SCA3, but similar SARA scores.

CONCLUSIONS

Cerebellar dysfunction, as measured with the CCFS and SARA scales, was more severe in FRDA than in patients with SCA, but with lower progression indexes, within the limits of these types of indexes. Ceiling effects may occur at late stages, for both scales. The CCFS scale is rater-independent and could be used in a multicentre context, as it is simple, rapid and fully automated.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT02069509.

Scales for the clinical evaluation of cerebellar disorders

Clinical scales represent an important tool not only for the initial grading/scoring of disease and assessment of progression, but also for the quantification of therapeutic effects in clinical trials. There are several scales available for the clinical evaluation of cerebellar symptoms. While some scales have been developed and evaluated for specific cerebellar disorders such as Friedreich ataxia, others reliably capture cerebellar symptoms with no respect to the underlying etiology. Each scale has its strengths and weaknesses. Extensive scales are certainly useful for thorough documentation of specific features of certain phenotypes, but this gain of information is not always essential for the purpose of a study. Therefore, compact and manageable scales like the Scale for the Assessment and Rating of Ataxia (SARA) or Brief Ataxia Rating Scale (BARS) are often preferred compared to more complex scales in observational and therapeutic studies.

The Subclinical Cardiomyopathy of Friedreich's Ataxia in a Pediatric Population

BACKGROUND

Identification of a subclinical cardiomyopathy in pediatric patients with Friedreich's ataxia (FA) has not been well-described.

METHODS

We performed echocardiography (Echo), cardiac magnetic resonance imaging (cMRI), and neurologic assessment in a cross-sectional analysis of 48 genetically confirmed FA subjects aged 9-17 years with moderate neurologic impairment but without a cardiovascular history. Echo- and cMRI-determined left ventricular mass were indexed (LVMI) to height in grams/m^2.7. LV remodeling was categorized as concentric remodeling (CR), concentric hypertrophy (CH), or eccentric hypertrophy based upon Echo- determined relative LV wall thickness.

RESULTS

Echo LVMI exceeded age-based normal values in 85% of subjects, and cMRI-determined LVMI correlated with depression of both diastolic and systolic tissue Doppler velocity (E': r = -0.65, P < .001, S': r = -0.46, P < .001) as well as increased early diastolic Doppler flow velocity/tissue velocity ratio (r= 0.55, P < .001), a marker of elevated LV filling pressure. Similar associations were found with echo-determined LV mass. Evidence of depressed LV relaxation and increased LV stiffness were observed in 88% and 71%, of subjects, respectively, despite a normal LV ejection fraction in almost all cases (mean = 60% + 7%). CR and CH were present in 40% and 44% of the study group, respectively, although significant depressions of E' and S' were observed only in subjects with CH (P < .005).

CONCLUSIONS

A subclinical hypertrophic cardiomyopathy is common in pediatric FA patients and CH is associated with both diastolic and systolic dysfunction.

Cerebellar ataxia and intrathecal baclofen therapy: Focus on patients´ experiences

Elucidating patients´ experiences of living with chronic progressive hereditary ataxia and the symptomatic treatment with intrathecal baclofen (ITB) is the objective of the current study. A multicenter qualitative study with four patients included due to the rare combination of hereditary ataxia and ITB therapy was designed to elucidate participants’ experiences through semi-structured interviews. The transcribed text was analyzed according to content analysis guidelines. Overall we identified living in the present/ taking one day at a time as the main theme covering the following categories: 1) Uncertainty about the future as a consequence of living with a hereditary disease; The disease; 2) Impact on life as a whole, 3) Influence on personal life in terms of feeling forced to terminate employment, 4) Limiting daily activities, and 5) ITB therapy, advantages, and disadvantages. Uncertainty about the future was the category that affected participants’ personal life, employment, and daily activities. The participants’ experience of receiving ITB therapy was expressed in terms of improved quality of life due to better body position and movement as well as better sleep and pain relief.

Longitudinal gait and balance decline in Friedreich's Ataxia: A pilot study

INTRODUCTION

Friedreich's Ataxia (FA) is a devastating, progressive, neurodegenerative disease. Objective measures that detect changes in neurological function in FA patients are needed to facilitate therapeutic clinical trials. The purpose of this pilot study was to analyze longitudinal changes in gait and balance in subjects with FA using the GAITRite Walkway System^® and Biodex Balance System™, respectively, and to test the ability of these measures to detect change over time compared to the Friedreich's Ataxia Rating Scale (FARS).

METHODS

This was a 24-month longitudinal study comparing ambulatory FA subjects with age- and gender-matched, healthy controls. Eight FA subjects and 8 controls were tested at regular intervals using the GAITRite and Biodex Balance systems and the FARS.

RESULTS

In the FA group, comfortable and fast gait velocity declined 8.0% and 13.9% after 12 months and 24.1% and 30.3% after 24 months, respectively. Postural stability indices increased in FA subjects an average of 41% from baseline to 24 months, representing a decline in balance. Subjects with FA also demonstrated a 17.7% increase in FARS neurological exam scores over 24 months. There were no changes in gait or balance variables in controls. In the FA group, multiple gait and balance measures correlated significantly with FARS neurological exam scores.

CONCLUSIONS

The GAITRite and Biodex Balance systems provided objective and clinically relevant measures of functional decline in subjects with FA that correlated significantly with performance measures in the FARS. Gait velocity may be an important objective measure to identify disease progression in adults with FA.

Friedreich Ataxia: current status and future prospects

Friedreich ataxia (FA) represents the most frequent type of inherited ataxia. Most patients carry homozygous GAA expansions in the first intron of the frataxin gene on chromosome 9. Due to epigenetic alterations, frataxin expression is significantly reduced. Frataxin is a mitochondrial protein. Its deficiency leads to mitochondrial iron overload, defective energy supply and generation of reactive oxygen species. This review gives an overview over clinical and genetic aspects of FA and discusses current concepts of frataxin biogenesis and function as well as new therapeutic strategies.

Pharmacological treatments for Friedreich ataxia

BACKGROUND

Friedreich ataxia is a rare inherited autosomal recessive neurological disorder, characterised initially by unsteadiness in standing and walking, slowly progressing to wheelchair dependency usually in the late teens or early twenties. It is associated with slurred speech, scoliosis, and pes cavus. Heart abnormalities cause premature death in 60% of people with the disorder. There is no easily defined clinical or biochemical marker and no known treatment. This is the second update of a review first published in 2009 and previously updated in 2012.

OBJECTIVES

To assess the effects of pharmacological treatments for Friedreich ataxia.

SEARCH METHODS

On 29 February 2016 we searched The Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, EMBASE and CINAHL Plus. On 7 March 2016 we searched ORPHANET and TRIP. We also checked clinical trials registers for ongoing studies.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) or quasi-RCTs of pharmacological treatments (including vitamins) in people with genetically-confirmed Friedreich ataxia. The primary outcome was change in a validated Friedreich ataxia neurological score after 12 months. Secondary outcomes were changes in cardiac status as measured by magnetic resonance imaging or echocardiography, quality of life, mild and serious adverse events, and survival. We excluded trials of duration shorter than 12 months.

DATA COLLECTION AND ANALYSIS

Three review authors selected trials and two review authors extracted data. We obtained missing data from the two RCTs that met our inclusion criteria. We collected adverse event data from included studies. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified more than 12 studies that used antioxidants in the treatment of Friedreich ataxia, but only two small RCTs, with a combined total of 72 participants, both fulfilled the selection criteria for this review and published results. One of these trials compared idebenone with placebo, the other compared high-dose versus low-dose coenzyme Q10 and vitamin E (the trialists considered the low-dose medication to be the placebo). We identified two other completed RCTs, which remain unpublished; the interventions in these trials were pioglitazone (40 participants) and idebenone (232 participants). Other RCTs were of insufficient duration for inclusion.In the included studies, the primary outcome specified for the review, change in a validated Friedreich ataxia rating score, was measured using the International Co-operative Ataxia Rating Scale (ICARS). The results did not reveal any significant difference between the antioxidant-treated and the placebo groups (mean difference 0.79 points, 95% confidence interval -1.97 to 3.55 points; low-quality evidence).The published included studies did not assess the first secondary outcome, change in cardiac status as measured by magnetic resonance imaging. Both studies reported changes in cardiac measurements assessed by echocardiogram. The ejection fraction was not measured in the larger of the included studies (44 participants). In the smaller study (28 participants), it was normal at baseline and did not change with treatment. End-diastolic interventricular septal thickness showed a small decrease in the smaller of the two included studies. In the larger included study, there was no decrease, showing significant heterogeneity in the study results; our overall assessment of the quality of evidence for this outcome was very low. Left ventricular mass (LVM) was only available for the smaller RCT, which showed a significant decrease. The relevance of this change is unclear and the quality of evidence low.There were no deaths related to the treatment with antioxidants. We considered the published included studies at low risk of bias in six of seven domains assessed. One unpublished included RCT, a year-long study using idebenone (232 participants), published an interim report in May 2010 stating that the study reached neither its primary endpoint, which was change in the ICARS score, nor a key cardiological secondary endpoint, but data were not available for verification and analysis.

AUTHORS' CONCLUSIONS

Low-quality evidence from two small, published, randomised controlled trials neither support nor refute an effect from antioxidants (idebenone, or a combination of coenzyme Q10 and vitamin E) on the neurological status of people with Friedreich ataxia, measured with a validated neurological rating scale. A large unpublished study of idebenone that reportedly failed to meet neurological or key cardiological endpoints, and a trial of pioglitazone remain unpublished, but on publication will very likely influence quality assessments and conclusions. A single study of idebenone provided low-quality evidence for a decrease in LVM, which is of uncertain clinical significance but of potential importance that needs to be clarified. According to low-quality evidence, serious and non-serious adverse events were rare in both antioxidant and placebo groups. No non-antioxidant agents have been investigated in RCTs of 12 months' duration.

Advances in management of movement disorders in children

Movement disorders in children are causally and clinically heterogeneous and present in a challenging developmental context. Treatment options are broad ranging, from pharmacotherapy to invasive neuromodulation and experimental gene and stem cell therapies. The clinical effects of these therapies are variable and often poorly sustained, and only a few of the management strategies used in paediatric populations have been tested in randomised controlled studies with age-appropriate cohorts. Identification of the most appropriate treatment is uniquely challenging in children because of the incomplete knowledge about the pathophysiology of movement disorders and their influence on normal motor development; thus, effective therapeutic options for these children remain an unmet need. It is vital to transfer the expanding knowledge of the movement disorders into the development of novel symptomatic or, ideally, disease-modifying treatments, and to assess these therapeutic strategies in appropriately designed and well done trials.

Friedreich Ataxia: From the Eye of a Molecular Biologist

Friedreich ataxia (FRDA) is caused by the expansion of a GAA triplet repeat in the first intron of the FXN gene. This disease was named after Nicholaus Friedreich, Germany, who depicted the essential finding. Among ataxias, FRDA is the most common hereditary ataxia. It has the autosomal recessive pattern of inheritance. The expansion of the GAA triplet repeat hinders the transcription, thereby reducing the level of the FXN transcript and consequently reducing the level of frataxin, a 210-amino acid protein. The disease pathogenesis is fundamentally due to a lack of frataxin, which is claimed to play a role in iron-sulfur cluster synthesis. Oxidative stress builds up as a result of Fe accumulation in the mitochondria, causing degeneration of the cells, which primarily occurs in the neurons and later in the cardiac tissues, and to some extent in the pancreas. The therapeutic interventions are at infancy; however, current treatments are targeted toward the reduction of iron overload and its effects.

Molecular and clinical study of a cohort of 110 Algerian patients with autosomal recessive ataxia

BACKGROUND

Autosomal recessive cerebellar ataxias (ARCA) are a complex group of neurodegenerative disorders with great genetic and phenotypic heterogeneity, over 30 genes/loci have been associated with more than 20 different clinical forms of ARCA. Genetic heterogeneity combined with highly variable clinical expression of the cerebellar symptoms and overlapping features complicate furthermore the etiological diagnosis of ARCA. The determination of the most frequent mutations and corresponding ataxias, as well as particular features specific to a population, are mandatory to facilitate and speed up the diagnosis process, especially when an appropriate treatment is available.

METHODS

We explored 166 patients (115 families) refered to the neurology units of Algiers central hospitals (Algeria) with a cerebellar ataxia phenotype segregating as an autosomal recessive pattern of inheritance. Genomic DNA was extracted from peripheral blood samples and mutational screening was performed by PCR and direct sequencing or by targeted genomic capture and massive parallel sequencing of 57 genes associated with inherited cerebellar ataxia phenotypes.

RESULTS

In this work we report the clinical and molecular results obtained on a large cohort of Algerian patients (110 patients/76 families) with genetically determined autosomal recessive ataxia, representing 9 different types of ARCA and 23 different mutations, including 6 novel ones. The five most common ARCA in this cohort were Friedreich ataxia, ataxia with isolated vitamin E deficiency, ataxia with oculomotor apraxia type 2, autosomal recessive spastic ataxia of Charlevoix-Saguenay and ataxia with oculomotor apraxia type 1.

CONCLUSION

We report here a large cohort of patients with genetically determined autosomal recessive ataxia and the first study of the genetic context of ARCA in Algeria. This study showed that in Algerian patients, the two most common types of ataxia (Friedreich ataxia and ataxia with isolated vitamin E deficiency) coexist with forms that may be less common or underdiagnosed. To refine the genotype/phenotype correlation in rare and heteregeneous diseases as autosomal recessive ataxias, more extensive epidemiological investigations and reports are necessary as well as more accurate and detailed clinical characterizations. The use of standardized clinical and molecular protocols would thus enable a better knowledge of the different forms of ARCA.

Sensorimotor skills in Fxn KO/Mck mutants deficient for frataxin in muscle

Friedreich ataxia is the most common autosomal recessive disorder of the cerebellum, causing degeneration of spinal sensory neurons and spinocerebellar tracts. The disease is caused by severely reduced levels of frataxin, a mitochondrial protein involved in iron metabolism. An experimental model has been generated by crossing mice homozygous for a conditional allele of the Fxn gene with mice heterozygous for a deleted exon 4 of Fxn carrying a tissue-specific Cre transgene under control of the muscle creatine kinase promoter. Relative to wild-type, Fxn null mutants were impaired on tests of motor coordination comprising horizontal bar, vertical pole, and the rotorod as well as displaying gait anomalies and the hindlimb clasping response. The Fxn KO/Mck model reproduces some key features of patients with Friedreich ataxia and provides an opportunity of ameliorating their symptoms with experimental therapies.

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

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.

Ataxias with Autosomal, X-Chromosomal or Maternal Inheritance

Heredoataxias are a group of genetic disorders with a cerebellar syndrome as the leading clinical manifestation. The current classification distinguishes heredoataxias according to the trait of inheritance into autosomal dominant, autosomal recessive, X-linked, and maternally inherited heredoataxias. The autosomal dominant heredoataxias are separated into spinocerebellar ataxias (SCA1-8, 10-15, 17-23, 25-30, and dentato-rubro-pallido-luysian atrophy), episodic ataxias (EA1-7), and autosomal dominant mitochondrial heredoataxias (Leigh syndrome, MIRAS, ADOAD, and AD-CPEO). The autosomal recessive ataxias are separated into Friedreich ataxia, ataxia due to vitamin E deficiency, ataxia due to Abeta-lipoproteinemia, Refsum disease, late-onset Tay-Sachs disease, cerebrotendineous xanthomatosis, spinocerebellar ataxia with axonal neuropathy, ataxia telangiectasia, ataxia telangiectasia-like disorder, ataxia with oculomotor apraxia 1 and 2, spastic ataxia of Charlevoix-Saguenay, Cayman ataxia, Marinesco-Sjögren syndrome, and autosomal recessive mitochondrial ataxias (AR-CPEO, SANDO, SCAE, AHS, IOSCA, MEMSA, LBSL CoQ-deficiency, PDC-deficiency). Only two of the heredoataxias, fragile X/tremor/ataxia syndrome, and XLSA/A are transmitted via an X-linked trait. Maternally inherited heredoataxias are due to point mutations in genes encoding for tRNAs, rRNAs, respiratory chain subunits or single large scale deletions/duplications of the mitochondrial DNA and include MELAS, MERRF, KSS, PS, MILS, NARP, and non-syndromic mitochondrial disorders. Treatment of heredoataxias is symptomatic and supportive and may have a beneficial effect in single patients.

**Please see page 424 for abbreviation list.

Consensus paper: management of degenerative cerebellar disorders

Treatment of motor symptoms of degenerative cerebellar ataxia remains difficult. Yet there are recent developments that are likely to lead to significant improvements in the future. Most desirable would be a causative treatment of the underlying cerebellar disease. This is currently available only for a very small subset of cerebellar ataxias with known metabolic dysfunction. However, increasing knowledge of the pathophysiology of hereditary ataxia should lead to an increasing number of medically sensible drug trials. In this paper, data from recent drug trials in patients with recessive and dominant cerebellar ataxias will be summarized. There is consensus that up to date, no medication has been proven effective. Aminopyridines and acetazolamide are the only exception, which are beneficial in patients with episodic ataxia type 2. Aminopyridines are also effective in a subset of patients presenting with downbeat nystagmus. As such, all authors agreed that the mainstays of treatment of degenerative cerebellar ataxia are currently physiotherapy, occupational therapy, and speech therapy. For many years, well-controlled rehabilitation studies in patients with cerebellar ataxia were lacking. Data of recently published studies show that coordinative training improves motor function in both adult and juvenile patients with cerebellar degeneration. Given the well-known contribution of the cerebellum to motor learning, possible mechanisms underlying improvement will be outlined. There is consensus that evidence-based guidelines for the physiotherapy of degenerative cerebellar ataxia need to be developed. Future developments in physiotherapeutical interventions will be discussed including application of non-invasive brain stimulation.

Molecular and clinical investigation of Iranian patients with Friedreich ataxia

BACKGROUND

Friedreich ataxia (FRDA) is an autosomal recessive disorder caused by guanine-adenine-adenine (GAA) triplet expansions in the FXN gene. Its product, frataxin, which severely reduces in FRDA patients, leads to oxidative damage in mitochondria. The purpose of this study was to evaluate the triple nucleotide repeated expansions in Iranian FRDA patients and to elucidate distinguishable FRDA clinical differences in these patients.

METHODS

A number of 22 Iranian patients (8 females and 14 males) from 16 unrelated families were studied. DNA was extracted from the peripheral blood of patients. The frequency and length of (GAA)n repeats in intron 1 of the FXN gene were analyzed using long-range PCR. In this study, the clinical criteria of FRDA in our patients and the variability in their clinical signs were also demonstrated.

RESULTS

An inverse relationship was observed between GAA repeat size and the age of onset. Although some distinguishable clinical features (such as limb ataxia and lower limb areflexia) were found in our patients, 90-95% of them had extensor plantar response and dysarthria. The results showed only one positive diabetes patient and also different effects on eye movement abnormality among our patients.

CONCLUSION

The onset age of symptoms showed a significant inverse correlation with allele size in our patients (P>0.05). Based on comparisons of the clinical data of all patients, clinical presentation of FRDA in Iranian patients did not differ significantly from other FRDA patients previously reported.

Does intrathecal baclofen have a place in the treatment of painful spasms in friedreich ataxia?

We present the case of a 50-year-old female patient with Friedreich ataxia (FA) who was treated successfully with an intrathecal baclofen (ITB)-delivering pump for painful spasms. To our knowledge, this is the second reported case of FA where ITB relieved painful and disabling spasms. We suggest that ITB should be considered in the treatment of disabling spasms in patients with FA.

Clinical neurogenetics: friedreich ataxia

Friedreich ataxia is the most common autosomal recessive ataxia. It is a progressive neurodegenerative disorder, typically with onset before 20 years of age. Signs and symptoms include progressive ataxia, ascending weakness and ascending loss of vibration and joint position senses, pes cavus, scoliosis, cardiomyopathy, and arrhythmias. There are no disease-modifying medications to either slow or halt the progression of the disease, but research investigating therapies to increase endogenous frataxin production and decrease the downstream consequences of disrupted iron homeostasis is ongoing. Clinical trials of promising medications are underway, and the treatment era of Friedreich ataxia is beginning.

Co-enzyme Q10 and idebenone use in Friedreich's ataxia

Friedreich's ataxia is a debilitating progressive neurodegenerative disease associated with cardiomyopathy and other features. The underlying cause is a deficiency of the mitochondrial protein frataxin which causes mitochondrial iron deposition, increased oxidative stress and impaired adenosine triphosphate production. Over the last 15 years, multiple clinical trials have assessed the efficacy of antioxidant agents in this disease. This article reviews trials of the two most important agents, namely co-enzyme Q10 and idebenone.

Deferiprone and idebenone rescue frataxin depletion phenotypes in a Drosophila model of Friedreich's ataxia

Friedreich's ataxia (FRDA), the most common inherited ataxia, is a neurodegenerative disease caused by a reduction in the levels of the mitochondrial protein frataxin, the function of which remains a controversial matter. Several therapeutic approaches are being developed to increase frataxin expression and reduce the intramitochondrial iron aggregates and oxidative damage found in this disease. In this study, we tested separately the response of a Drosophila RNAi model of FRDA (Llorens et al., 2007) to treatment with the iron chelator deferiprone (DFP) and the antioxidant idebenone (IDE), which are both in clinical trials. The FRDA flies have a shortened life span and impaired motor coordination, and these phenotypes are more pronounced in oxidative stress conditions. In addition, under hyperoxia, the activity of the mitochondrial enzyme aconitase is strongly reduced in the FRDA flies. This study reports that DFP and IDE improve the life span and motor ability of frataxin-depleted flies. We show that DFP eliminates the excess of labile iron in the mitochondria and thus prevents the toxicity induced by iron accumulation. IDE treatment rescues aconitase activity in hyperoxic conditions. These results validate the use of our Drosophila model of FRDA to screen for therapeutic molecules to treat this disease.

Rating disease progression of Friedreich's ataxia by the International Cooperative Ataxia Rating Scale: analysis of a 603-patient database

The aim of this cross-sectional study was to analyse disease progression in Friedreich's ataxia as measured by the International Cooperative Ataxia Rating Scale. Single ratings from 603 patients with Friedreich's ataxia were analysed as a function of disease duration, age of onset and GAA repeat lengths. The relative contribution of items and subscales to the total score was studied as a function of disease progression. In addition, the scaling properties were assessed using standard statistical measures. Average total scale progression per year depends on the age of disease onset, the time since diagnosis and the GAA repeat length. The age of onset inversely correlates with increased GAA repeat length. For patients with an age of onset ≤14 years associated with a longer repeat length, the average yearly rate of decline was 2.5 ± 0.18 points in the total International Cooperative Ataxia Rating Scale for the first 20 years of disease duration, whereas patients with a later onset progress more slowly (1.8 ± 0.27 points/year). Ceiling effects in posture, gait and lower limb scale items lead to a reduced sensitivity of the scale in the severely affected population with a total score of >60 points. Psychometric scaling analysis shows generally favourable properties for the total scale, but the subscale grouping could be improved. This cross-sectional study provides a detailed characterization of the International Cooperative Ataxia Rating Scale. The analysis further provides rates of change separated for patients with early and late disease onset, which is driven by the GAA repeat length. Differences in the subscale dynamics merit consideration in the design of future clinical trials applying this scale as a neurological assessment instrument in Friedreich's ataxia.

Antioxidants and other pharmacological treatments for Friedreich ataxia

BACKGROUND

Friedreich ataxia is a rare inherited autosomal recessive neurological disorder, characterised initially by unsteadiness in standing and walking, slowly progressing to wheelchair dependency usually in the late teens or early twenties. It is associated with slurred speech, scoliosis and pes cavus. Heart abnormalities cause premature death in 60% to 80% of people with the disorder. There is no easily defined clinical or biochemical marker and no known treatment. This is the first update of a review published in 2009.

OBJECTIVES

To examine the efficacy of antioxidants and other pharmacological treatments for Friedreich ataxia.

SEARCH METHODS

We searched The Cochrane Neuromuscular Disease Group Specialized Register (11 July 2011), CENTRAL (2011, Issue 3), MEDLINE (January 1966 to July 2011), EMBASE (January 1980 to July 2011), AMED (January 1985 to July 2011), CINAHL Plus (January 1937 to July 2011), LILACS (January 1982 to July 2011), ORPHANET (1990 to July 2011), TRIP (1998 to July 2011) and PEDRO (October 1999 to July 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs of drug treatment in people with genetically confirmed Friedreich ataxia. The primary outcome was change in ataxia rating scale as measured by the International Co-operative Ataxia Rating Scale (ICARS) after 12 months. Secondary outcomes included change in left ventricular heart mass as measured by magnetic resonance imaging or echocardiography. We excluded trials of shorter duration than 12 months.

DATA COLLECTION AND ANALYSIS

Three authors selected the trials and two authors extracted data. We obtained missing data from the one RCT that met our inclusion criteria. We planned to collect adverse event data from included studies.

MAIN RESULTS

More than 10 studies used idebenone in the treatment of Friedreich ataxia but only one small RCT, with 29 participants, using the synthetic antioxidant idebenone 5 mg/kg, fulfilled the selection criteria for this review. Other RCTs were of insufficient duration. We identified no additional RCT when the searches were updated in 2011. In the included study, the primary outcome specified for this review, change in ICARS scale, did not reveal any significant differences with idebenone treatment compared to placebo. The secondary outcome of change in left ventricular heart mass index as measured by magnetic resonance spectroscopy was not assessed. The second secondary outcome, change in left ventricular mass as measured by echocardiography, did improve significantly; there was a 10.7% worsening after 12 months of treatment in the placebo group and a 5.6% improvement in the idebenone group. The mean difference was 16.37% (95% CI 95% 2% to 31%). There were no adverse events. We considered the included study at low risk of bias in five of the seven domains assessed. A larger trial using idebenone published an interm report in May 2010 stating that the study had failed to reach its primary endpoint, which was change in the ICARS scale.

AUTHORS' CONCLUSIONS

No RCT using idebenone or any other pharmacological treatment has shown significant benefit on neurological symptoms associated with Friedreich ataxia. Idebenone has shown a positive effect on left ventricular heart mass but the clinical relevance of this change was not assessed in the included study.

Characterising the neuropathology and neurobehavioural phenotype in Friedreich ataxia: a systematic review

Friedreich ataxia (FRDA), the most common of the hereditary ataxias, is an autosomal recessive, multisystem disorder characterised by progressive ataxia, sensory symptoms, weakness, scoliosis and cardiomyopathy. FRDA is caused by a GAA expansion in intron one of the FXN gene, leading to reduced levels of the encoded protein frataxin, which is thought to regulate cellular iron homeostasis. The cerebellar and spinocerebellar dysfunction seen in FRDA has known effects on motor function; however until recently slowed information processing has been the main feature consistently reported by the limited studies addressing cognitive function in FRDA. This chapter will systematically review the current literature regarding the neuropathological and neurobehavioural phenotype associated with FRDA. It will evaluate more recent evidence adopting systematic experimental methodologies that postulate that the neurobehavioural phenotype associated with FRDA is likely to involve impairment in cerebello-cortico connectivity.

Annual change in Friedreich's ataxia evaluated by the Scale for the Assessment and Rating of Ataxia (SARA) is independent of disease severity

BACKGROUND

The objective of the study was to evaluate the sensitivity to change of the Scale for the Assessment and Rating of Ataxia (score, 0-40) in Friedreich's ataxia.

METHODS

This was a follow-up study in adult patients with genetically confirmed Friedreich's ataxia evaluated at least twice (minimum interval, 6 months). Participants were outpatients at the Center for Neurogenetics of the Pitie-Salpêtrière Hospital in Paris.

RESULTS

We included 84 patients; 60% had 3 or more evaluations. The mean score on first assessment was 22.7 ± 9, and the mean follow-up was 1.84 ± 1.10 years. The mean increase was 1.36 ± 2.3 points/year; this variation was not significantly linked to factors known to influence disease severity such as age at onset, disease duration, GAA expansion length, and wheelchair use.

CONCLUSIONS

In adult Friedreich's ataxia patients the Scale for the Assessment and Rating of Ataxia can detect annual changes independently of disease severity. In future therapeutic trials no patient stratification is globally required.

Combined therapy with idebenone and deferiprone in patients with Friedreich's ataxia

Iron chelators are a new therapeutical approach for patients with Friedreich's ataxia, on the basis that oxidative cell damage that occurs in these patients is due to the increasing deposits of mitochondrial iron pools. The objective of the study was to evaluate the effects of the combined therapy of idebenone and low oral doses of deferiprone on the neurological signs and cardiac function parameters. This study was designed as a prospective open-label single-arm study. Twenty Friedreich's ataxia patients were treated with idebenone (20 mg/kg/day) and deferiprone (20 mg/kg/day) for 11 months. Patients were evaluated before the start and throughout the study with the International Cooperative Ataxia Rating Scale (ICARS) scores, echocardiographic measurements and MRI (magnetic resonance imaging) techniques to asses brain iron deposits in the dentate nucleus. No significant differences were observed in total ICARS scores when comparing baseline status and the end of the study in the whole group of patients. Posture and gait scores increased significantly after 11 months of therapy (Wilcoxon's test, p = 0.04) and kinetic function improved significantly (Wilcoxon's test, p = 0.015). Echocardiography data showed a significant reduction of the interventricular septum thickness (Wilcoxon's test, p = 0.04) and in the left ventricular mass index (Wilcoxon's test, p = 0.038) after the start of the therapy. The MRI values in the dentate nucleus showed a statistically significant reduction (Wilcoxon's test p = 0.007) between baseline conditions and after 11 months of the therapy. Combined therapy with idebenone and deferiprone in patients with FDRA indicates a stabilizing effect in neurologic dysfunctions due to an improvement in the kinetic functions, with a worsening of gait and posture scores. Heart hypertrophy parameters and iron deposits in dentate nucleus improved significantly. Combined therapy was well tolerated with mild side effects, apart from the risk of neutropenia and progressive reduction of plasma iron parameters.

Brain diffusion-weighted imaging in Friedreich's ataxia

BACKGROUND

Friedreich ataxia (FRDA) is the commonest form of autosomal recessive ataxia. This study aimed to define the extent of the brain damage in FRDA patients and to identify in vivo markers of neurodegeneration, using diffusion-weighted imaging (DWI).

METHODS

We studied 27 FRDA patients and 21 healthy volunteers using a 1.5 T scanner. Axial DW images were obtained and mean diffusivity (MD) maps were generated. Region of interests (ROIs) included medulla, pons, inferior, middle and superior cerebellar peduncles (ICP, SCP, MCP), dentate nucleus, cerebellar white matter, thalamus, caudate, putamen, pallidus, pyramidal tracts at level of posterior limb of internal capsule (PLIC), optic radiations (OR), and corpus callosum. Histograms of MD were generated for all pixels in the whole cerebral hemispheres and infratentorial compartment. Disease severity was assessed by the International Cooperative Ataxia Rating Scale (ICARS).

RESULTS

FRDA patients had significantly higher MD values than controls in medulla (P < 0.001), ICP (P < 0.001), MCP (P < 0.01), SCP (P < 0.001), OR (P < 0.001), and at the level of the infratentorial structures such as brainstem (P < 0.01), cerebellar hemispheres (P < 0.01), and especially in the cerebellar vermis (P < 0.001). MD values were strongly correlated with disease duration and ICARS score.

DISCUSSION

Our results showed that DWI is a suitable non-invasive technique to quantify the extent of neurodegeneration in FRDA, that appears more extended than previously reported, showing a microstructural involvement of structures such as OR and MCP.