The invention provides methods of treating diseases, disorders or injuries involving motor neuron survival and axonal growth, including amylotrophic lateral sclerosis, by the administration of a LINGO-2 antagonist. An exemplary method for promoting survival of a motor neuron, comprising contacting said motor neuron with an effective amount of a composition comprising a LINGO-2 antagonist selected from the group consisting of: (i) a soluble LINGO-2 polypeptide; (ii) a LINGO-2 antibody or antigen-binding fragment thereof; (iii) a LINGO-2 antagonist polynucleotide; (iv) a LINGO-2 aptamer; and (v) a combination of two or more of said LINGO-2 antagonists.