BDNF and amyotrophic lateral sclerosis: Several intrathecal therapies are currently being trialled in ALS, including anti-sense oligonucleotides (ASOs), mesenchymal stem cells (MSCs) and growth factors, such as brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF) and vascular endothelial growth factor (VEGF) [193].