- The subject has a rapid degenerative neurological disease such as lateral sclerosis, amyotrophic lateral sclerosis (ALS), rapidly progressive Multiple Sclerosis, inherited or rapidly progressive leukodystrophies, Moyamoya disease, cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL), thrombophilias, rapidly progressive autoimmune disorders, or any disorder where progression of the underlying spinal cord or a central nervous system (CNS) disease is expected to progress significantly over the next 3 years