Friedreich Ataxia Global Clinical Consortium UNIFIED Natural History Study

Change in modified Friedreich Ataxia Rating Scale (mFARS) Score

The modified Friedreich Ataxia Rating Scale (mFARS) is a disease-specific scale that measures progression of neurological effects of FA. The mFARS is a validated and reliable scale; comprised of the neurologic component of the FARS and evaluates bulbar, upper limb, lower limb, and upright stability/gait function. For each item, responses categorize the corresponding neurological finding, and the findings are assigned a score ranging from 0 to 3, 4, or 5 with 0 being normal and higher numbers indicative of greater impairment. The score ranges from 0 to 93. The score will be compared to the previous year annually for up to 25 years.

Change in Scale for the Assessment and Rating of Ataxia (SARA) Score

The Scale for the Assessment and Rating of Ataxia (SARA) is a semi-quantitative assessment of ataxia, measuring ataxia of upper limb, lower limb, gait, balance and speech. It has eight items: gait, stance, sitting, speech disturbance, finger chase, nose-finger test, fast alternating hand movement, and heel-shin slide. The total score ranges from 0 (no ataxia) to 40 (severe ataxia). The score will be compared to the previous year annually for up to 25 years.

Change in FA Activities of Daily Living (ADL) Score

The FARS-ADL is a subsection of the FARS questionnaire that assesses activities of daily living, including speech, personal hygiene, feeding, and mobility. Participants rank each category using a scale of 0 (normal) to 4 (severe disability/ inability to carry out activity independently), with lower scores indicative of "normal" function/activity. The score will be compared to the previous year annually for up to 25 years.

Change in Upright Stability (US) Score

The Upright Stability (US) assessment is part of the neurological examination within the Modified Friedreich Ataxia Rating Scale (mFARS). This component comprises nine items: sitting position, stance with feet apart, stance with feet apart and eyes closed, stance with feet together, stance with feet together and eyes closed, tandem stance, stance with dominant foot, tandem walk, and gait. The score ranges from 0 to 9, with a higher score reflecting poorer upright stability (i.e., greater neurological severity). The score will be compared to the previous year annually for up to 25 years.

Change in 9-hole peg test mean time (seconds)

The 9 Hole Peg Test (9HPT) examines finger dexterity and involves placing and removing nine pegs in a pegboard in the quickest possible time. Two consecutive trials of the dominant hand, followed immediately by two consecutive trials of the non-dominant hand, are undertaken. The average time in seconds taken to complete the task, for each of the dominant and non-dominant hand, is calculated. The 9HPT has high intra- and inter-rater reliability and is the most commonly used measure of upper limb function in FA. The score will be compared to the previous year annually for up to 25 years.

Change in Timed walk (25-foot or 8-meter) mean time (seconds)

The timed 25-foot/8-meter walk examines upright stability, balance and mobility and involves walking a predetermined distance. Two consecutive trials are undertaken. The average time in seconds taken to complete the task, is calculated. The score will be compared to the previous year annually for up to 25 years.

Change in Speech analysis scores

A battery of speech evaluations will be administered and recorded on a laptop for analysis, using Redenlab software. This will include: reading of a phonetically-balanced passage, sustained vowel sound, listing days of the week, repeating syllables, and a monologue task. This will form a measure of dysarthria. Redenlab is a US-Australian speech-testing company, https://redenlab.com. The score will be compared to the previous year annually for up to 25 years.

Change in Ataxia Instrumented Measures (AIMs)clinical severity score

The Ataxia Instrumented Measures (AIMs) system consists of three components: 1) the data logger which is either a spoon, cup or pendant each containing sensors, Wi-Fi and processor; 2) algorithms that distinguishes between movements made by control and users with ataxia and grades the severity of ataxia when detected; and 3) ataxia scores presented in a manner that has utility for clinicians (the AIM "score"). This score is continuous and features an ataxia severity threshold which has been established through the process of machine learning and is based on the separation between individuals with ataxia and control participants. Any value below the severity threshold of a specific device is expected for controls/very mild ataxia, and any value beyond is expected for individuals with moderate/severe ataxia. The score will be compared to the previous year annually for up to 25 years.