SARA—Scale for Assessment and Rating of Ataxia. This is an 8-category, 40-point scale. This scale assesses a single numeric value from 0 – 40 to reflect the combined severity of one’s ataxia symptoms. Category summary:
SARA is used by neurologists to assess an individual patient’s decline. Different people with the same score will have a different set of issues. Increases and decreases across the eight categories can cancel each other out; it is perhaps expected that each symptom will worsen and not improve.
Informative links:
https://www.physio-pedia.com/Scale_for_the_Assessment_and_Rating_of_Ataxia_(SARA)
http://www.ataxia-study-group.net/html/about/ataxiascales/sara/SARA.pdf
https://en.wikipedia.org/wiki/Dysmetria
Criticisms
SARA tries to cover symptoms common to all cerebellar ataxias and therefore doesn’t cover disease-specific symptoms, such as vestibulo-ocular areflexia, peripheral neuropathy, double vision, and neurogenic bladder dysfunction for SCA3.
SARA is susceptible to changes in different categories canceling each other out. There’s an assumption that one’s condition will only worsen and not improve, but then SARA is used for clinical drug trials, which increases the chances of this combination of worsening and improving.
Different neurologists will/would compute different SARA scores if computed independently (i.e., without a detailed breakdown as a starting point). The test is intended to be objective, but the human element prevails.
I and others can go a year or more with no change in our SARA scores but with issues clearly worsening. I cannot emphasize enough the worthlessness of using SARA as the primary outcome measure in a study, especially when testing goes for 6 – 12 months. (My SARA score in 2009 was 2, in 2014 was 4, and in 2019 was 20.) Especially in mildly symptomatic people, the SARA score might be increasing by zero to two points per year (i.e., a step function that is stable for one or two years, then jumps two to four points). If I ingest something for a full year and my SARA score doesn’t change during that time, everybody has learned absolutely nothing useful. For example: the trehalose tests.
The point-weights make little sense. If you transition from a walker to a wheelchair, that’s one point on the SARA scale. If you transition from having no speech disturbances to the suggestion of speech disturbances, that’s one point on the SARA scale.
Other scales
BARS—Brief Ataxia Rating Scale. This is an 8-category, 40-point scale.
ICARS—International Cooperative Ataxia Rating Scale. This is a 19-category, 100-point scale. More.
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