Date	Event	Description
22 October 2018	New search has been performed	Protocol modification in primary and secondary outcomes. Protocol modification in SMA type. Transformation of disability scores into MRC scores has been removed, since it is not possible for the included study population. We revised the methods to conform to current Cochrane standards.
20 June 2017	New citation required and conclusions have changed	Updated search October 2018. Four new trials included. Inclusion of 'Summary of findings' tables. Re‐evaluation of 'Risk of bias' assessments. One author (J Wokke) retired from authorship. Fay‐Lynn Asselmann joined the author team.