Study	Reason for exclusion
Arnold 2006	No control group or randomisation of participants
Artuch 2002	No control group or randomisation of participants
Artuch 2006	Single case study
Boesch 2007	No control group or randomisation of participants
Boesch 2008	No control group or randomisation of participants. Open‐label clinical pilot study
Bonnan 2008	No control group or randomisation
Botez 1996	Speech not included as an outcome measure
Botez 1997	Single case study
Broccoletti 2008	No control group or randomisation of participants
Ershova 2007	No control group
Heo 2008	No control group
Ilg 2012	No randomisation or placebo
Lagedrost 2011	6‐month extension of Lynch 2010, focused on cardiac outcomes
Meier 2012	No control group or randomisation of participants in the open label extension of Lynch 2010 and Lagedrost 2011 (the subsequent 12 months)
Melancon 1982	No randomisation
Nakamura 2009	No control group or randomisation of participants
Ogawa 2003	No randomisation. Single‐blinded only. Heterogenous group of spinocerebellar degeneration
Pineda 2008	No randomisation. Open‐label design
Shimizu 1999	No control group or placebo
Sobue 1980	No control group or placebo
Strupp 2011	No relevant outcome measures included
Trouillas 1984	No randomisation
Trouillas 1997	Unclear clinical diagnosis. All participants presented with a sporadic form of pure cerebellar cortical atrophy. Speech not reported as an outcome measure
Velasco‐Sanchez 2011	No control group or randomisation of participants
Yabe 1999	No control group or randomisation of participants