Current clinical rating scales to measure disease progression in people with spasticity and ataxia are focused solely on either spasticity symptoms (stiffness of muscles leading to involuntary spasms) or ataxia symptoms, not both. This is despite the fact that they can occur together. With this in mind, as part of the European PROgression chart of SPAstic ataxias (PROSPAX) Project, researchers have developed the SPAXCOM scale. The SPAXCOM scale has been designed to sensitively measure both spasticity and ataxia symptoms over time, known as a composite scale.
Longitudinal data from 127 people over the age 10 with Spastic Paraplegia Type 7 (SPG7) and 112 people with autosomal recessive Spastic Ataxia Charlevoix-Saguenay (ARSACS) were collected from study sites in seven European countries. These were Germany, Italy, Turkey, The Netherlands, France and the UK. The SPAXCOM scale, consisting of a combination of items from the Scale for Rating and Assessment of Ataxias (SARA), Spastic Paraplegia Rating Scale (SPRS), and the Activities of Daily Living subscale of the Friedreich’s Ataxia Rating Scale (FARS-ADL) was evaluated for its sensitivity to change over a 2-year period compared to the scales as they are normally used.
The results of this research showed that the SPAXCOM scale was better able to detect changes in disease progression in SPG7 and ARSACS and this was the case across a range of different genetic variants of the conditions. Only 7 of the 30 items tested were needed to achieve this higher sensitivity compared to the other scales.
The more sensitive to change a clinical scale is, the more accurately it is able to measure disease progression over time, and the smaller the number of participants that are needed to take part in a trial using this scale to measure outcomes, for example how effective a drug is in treating the condition. Therefore, these findings suggest that using SPAXCOM to measure progression of SPG7 and ARSACS in clinical trials may require fewer participants taking part in the trial. The more sensitive to change a clinical rating scale is, the shorter the timeframe needed for it to detect change in the progression of a disease.
Dr Sophie Tezenas Du Montcel, lead author on the paper reflects,
“This is the first scale that allows for the quantification of the progression of both ataxia and spasticity. The next steps will be to test this scale in independent cohorts and with longer follow-up periods”.
Read more about the PROSPAX Project here.
Read the paper here.
