Friedreich Ataxia Caregiver-Reported Health Index: Development of a Novel, Disease-Specific Caregiver-Reported Outcome Measure.

Background and Objectives: The Friedreich ataxia (FRDA) scientific community needs access to patient-centered outcome measures that satisfy regulatory guidelines and are capable of tracking clinically meaningful changes in FRDA disease burden. The objective of this research was to develop a novel, disease-specific caregiver-reported outcome measure for use in FRDA research and clinical care. Methods: In prior work, we conducted qualitative interviews and a cross-sectional study of FRDA caregivers and patients to determine the symptoms of greatest importance to individuals with FRDA. We designed the Friedreich Ataxia Caregiver-Reported Health Index (FACR-HI) to serially measure the symptoms of greatest importance to patients and utilized factor analysis, beta testing, reliability testing, and cross-sectional subgroup analysis to further evaluate and optimize this disease-specific outcome measure. Results: The FACR-HI was designed to measure total disease burden and disease burden in 18 symptomatic domains. The FACR-HI total score demonstrated high internal consistency (Cronbach's α = 0.98) and test-retest reliability (intraclass correlation coefficient = 0.96). Beta interview participants found the FACR-HI to be highly relevant, comprehensive, and easy to use. FACR-HI total and subscale scores were associated with functional staging for ataxia scores and speech impairment. Discussion: Initial evaluation of the FACR-HI supports its content validity, test-retest reliability, and construct validity as a caregiver-reported outcome measure for assessing how pediatric individuals with FRDA feel and function. The FACR-HI provides a potential mechanism to quantify changes in multifactorial FRDA disease burden during future clinical trials.

Characterization of clinical serum cardiac biomarker levels in individuals with Friedreich ataxia.

Friedreich ataxia is a progressive autosomal recessive neurodegenerative disorder characterized by ataxia, dyscoordination, and cardiomyopathy. A subset of patients with Friedreich ataxia have elevated levels of serum cardiac troponin I, but associations with disease outcomes and features of cardiomyopathy remain unclear. In this study, we characterized clinically obtained serum cardiac biomarker levels including troponin I, troponin T, and B-type natriuretic peptide in subjects with Friedreich ataxia and evaluated their association with markers of disease. While unprovoked troponin I levels were elevated in 36% of the cohort, cTnI levels associated with a cardiac event (provoked) were higher than unprovoked levels. In multivariate linear regression models, younger age predicted increased troponin I values, and in logistic regression models younger age, female sex, and marginally longer GAA repeat length predicted abnormal troponin I levels. In subjects with multiple assessments, mean unprovoked troponin I levels decreased slightly over time. The presence of abnormal troponin I values and their levels were predicted by echocardiographic measures of hypertrophy. In addition, troponin I levels predicted long-term markers of clinical cardiac dysfunction over time to a modest degree. Consequently, troponin I values provide a marker of hypertrophy but only a minimally predictive biomarker for later cardiac manifestations of disease such as systolic dysfunction or arrhythmia.

Friedreich's Ataxia-Health Index: Development and Validation of a Novel Disease-Specific Patient-Reported Outcome Measure.

Background and Objectives: To develop a valid, disease-specific, patient-reported outcome (PRO) measure for adolescents and adults with Friedreich ataxia (FA) for use in therapeutic trials. Methods: We conducted semistructured qualitative interviews and a national cross-sectional study of individuals with FA to determine the most prevalent and burdensome symptoms and symptomatic themes to this population. These symptoms and symptomatic themes were included as questions in the first version of the Friedreich's Ataxia-Health Index (FA-HI). We subsequently used factor analysis, beta interviews with 17 individuals with FA, and test-retest reliability assessments with 20 individuals with FA to evaluate, refine, and optimize the FA-HI. Finally, we determined the capability of the FA-HI to differentiate between subgroups of FA participants with varying levels of disease severity. Results: Participants with FA identified 18 symptomatic themes of importance to be included as subscales in the FA-HI. The FA-HI demonstrates high internal consistency and test-retest reliability, and it was identified by participants as highly relevant, comprehensive, and easy to complete. FA-HI total and subscale scores statistically differentiated between subgroups of participants with varying levels of disease burden. Discussion: Initial evaluation of the FA-HI supports its validity and reliability as a PRO for assessing how individuals with FA feel and function.

Retinal hypoplasia and degeneration result in vision loss in Friedreich ataxia.

OBJECTIVE: Friedreich ataxia (FRDA) is an inherited condition caused by a GAA triplet repeat (GAA-TR) expansion in the FXN gene. Clinical features of FRDA include ataxia, cardiomyopathy, and in some, vision loss. In this study, we characterize features of vision loss in a large cohort of adults and children with FRDA. METHODS: Using optical coherence tomography (OCT), we measured peripapillary retinal nerve fiber layer (RNFL) thickness in 198 people with FRDA, and 77 controls. Sloan letter charts were used to determine visual acuity. RNFL thickness and visual acuity were compared to measures of disease severity obtained from the Friedreich Ataxia Clinical Outcomes Measures Study (FACOMS). RESULTS: The majority of patients, including children, had pathologically thin RNFLs (mean = 73 ± 13 µm in FRDA; 98 ± 9 µm in controls) and low-contrast vision deficits early in the disease course. Variability in RNFL thickness in FRDA (range: 36 to 107 µm) was best predicted by disease burden (GAA-TR length X disease duration). Significant deficits in high-contrast visual acuity were apparent in patients with an RNFL thickness of ≤68 µm. RNFL thickness decreased at a rate of -1.2 ± 1.4 µm/year and reached 68 µm at a disease burden of approximately 12,000 GAA years, equivalent to disease duration of 17 years for participants with 700 GAAs. INTERPRETATION: These data suggest that both hypoplasia and subsequent degeneration of the RNFL may be responsible for the optic nerve dysfunction in FRDA and support the development of a vision-directed treatment for selected patients early in the disease to prevent RNFL loss from reaching the critical threshold.

Omaveloxolone: an activator of Nrf2 for the treatment of Friedreich ataxia.

INTRODUCTION: Friedreich ataxia (FRDA) is a rare autosomal recessive degenerative disorder characterized by ataxia, dysarthria, diabetes, cardiomyopathy, scoliosis, and occasionally vision loss in late-stage disease. The discovery of the abnormal gene in FRDA and its product frataxin has provided insight into the pathophysiology and mechanisms of treatment. AREAS COVERED: Although the neurologic phenotype of FRDA is well defined, there are currently no established pharmacological treatments. Omaveloxolone, a nuclear factor erythroid 2-related factor 2 (Nrf2) activator, is currently under review by the Food and Drug Administration (FDA) and has the potential to be the first approved treatment for FRDA. In the present report, we have reviewed the basic and clinical literature on Nrf2 deficiency in FRDA, and evidence for the benefit of omaveloxolone. EXPERT OPINION: The present perspective suggests that omaveloxolone is a rational and efficacious therapy that is possibly disease modifying in treatment of FRDA.

Patient-Reported Impact of Symptoms in Friedreich Ataxia.

BACKGROUND AND OBJECTIVES: To determine the prevalence and relative importance of symptoms experienced by children and adults with Friedreich ataxia (FA) and to identify factors associated with a higher burden of disease. METHODS: We conducted qualitative interviews with individuals with FA and caregivers of pediatric individuals with FA to identify potential symptoms of importance to those living with FA. We subsequently performed a cross-sectional study to assess which symptoms have the highest prevalence and importance in FA and to determine which factors are associated with a higher burden of disease. RESULTS: Thirty-nine participants provided 2,527 quotes regarding the symptomatic burden of FA. Two hundred two individuals (153 individuals with FA and 49 caregivers) participated in a subsequent cross-sectional study. Individuals with FA and caregivers identified impaired coordination, limitations with mobility and walking, inability to do activities, fatigue, and lower extremity weakness as the most prevalent and life-altering symptomatic themes in FA. Muscle stiffness and functional staging for ataxia were associated with the prevalence of symptomatic themes in FA. In addition, the length of smaller GAA expansion and the mean length of both GAA expansions were strongly associated with the onset of symptoms in FA. DISCUSSION: There are a wide variety of symptoms that affect the lives of individuals with FA. These symptoms, many underrecognized, have different levels of importance and occur at different rates in the FA population. The most common and life altering of these symptoms represent potential targets for future therapeutic interventions.

Friedreich's Ataxia related Diabetes: Epidemiology and management practices.

AIMS: Friedreich's Ataxia (FRDA) is a progressive neuromuscular disorder typically caused by GAA triplet repeat expansions in both frataxin gene alleles. FRDA can be complicated by diabetes mellitus (DM). The objective of this study was to describe the prevalence of, risk factors for, and management practices of FRDA-related DM. METHODS: FACOMS, a prospective, multi-site natural history study, includes 1,104 individuals. Extracted data included the presence of DM and other co-morbidities, genetic diagnosis, and markers of disease severity. We performed detailed medical record review and a survey for the subset of individuals with FRDA-related DM followed at one FACOMS site, Children's Hospital of Philadelphia. RESULTS: FRDA-related DM was reported by 8.7% of individuals. Age, severe disease, and FRDA cardiac complications were positively associated with DM risk. FRDA-related DM was generally well-controlled, as reflected by HbA1c, though diabetic ketoacidosis did occur. Insulin is the mainstay of treatment (64-74% overall); in adults, metformin use was common and newer glucose-lowering agents were used rarely. CONCLUSIONS: Clinical factors identify individuals at increased risk for FRDA-related DM. Future studies should test strategies for FRDA-related DM screening and management, in particular the potential role for novel glucose-lowering therapies in preventing or delaying FRDA-related cardiac disease.

Outcomes of an inpatient medical nutritional rehabilitation protocol in children and adolescents with eating disorders.

BACKGROUND: Medical stabilization through inpatient nutritional rehabilitation is often necessary for patients with eating disorders (EDs) but includes the inherent risk of refeeding syndrome. Here we describe our experience of implementing and sustaining an inpatient nutritional rehabilitation protocol designed to strategically prepare patients with EDs and their families for discharge to a home setting in an efficient and effective manner from a general adolescent medicine unit. We report outcomes at admission, discharge, and 4-weeks follow-up. METHODS: Protocol development, implementation, and unique features of the protocol, are described. Data were collected retrospectively as part of a continuous quality improvement (QI) initiative. Safety outcomes were the clinical need for phosphorus, potassium, and magnesium supplementation, other evidence of refeeding syndrome, and unexpected readmissions within one month of discharge. The value outcome was length of stay (LOS). Treatment outcomes were the percentage median BMI (MBMI) change from admission to discharge, and from discharge to 4-weeks follow-up visit. RESULTS: A total of 215 patients (88% F, 12% M) were included. Patients averaged 15.3 years old (5.8-23.2y); 64% had AN, 18% had atypical anorexia (AtAN), 6% bulimia nervosa (BN), 5% purging disorder (PD), 4% avoidant-restrictive food intake disorder (ARFID), and 3% had an unspecified food and eating disorder (UFED). Average LOS was 11 days. Initial mean calorie level for patients at admission was 1466 and at discharge 3800 kcals/day. Phosphorus supplementation for refeeding hypophosphatemia (RH) was needed in 14% of inpatients; full-threshold refeeding syndrome did not occur. Only 3.8% were rehospitalized in the thirty days after discharge. Patients averaged 86.1% of a median MBMI for age and gender, 91.4% MBMI at discharge, and 100.9% MBMI at 4-weeks follow-up. Mean percentage MBMI differences between time points were significantly different (admission-discharge: 5.3%, p <0.001; discharge-follow-up: 9.2%, p <0.001). CONCLUSIONS: Implementation of the CHOP inpatient nutritional rehabilitation protocol aimed at rapid, efficient, and safe weight gain and integration of caregivers in treatment of patients with diverse ED diagnoses led to excellent QI outcomes in percentage MBMI at discharge and 4-weeks follow-up, while maintaining a short LOS and low rates of RH phosphorus supplementation.