The present invention relates to methods for treating disorders affecting motor function, such as motor function affected by disease, injury to the brain and/or spinal cord using an adeno-associated virus (AAV) gene therapy vector comprising adeno-associated virus 5 (AAV5) capsid proteins and a gene product of interest flanked by AAV ITRs. In particular, the gene therapy vector of the present invention is administered via injection into the cerebrospinal fluid (CSF), preferably by lumbar injection and/or injection into the cisterna magna.