The present invention relates to the fields of biology, genetics and medicine. In particular it concerns new methods for the detection, characterisation and/or treatment (or management) of neurodegenerative diseases, particularly amyotrophic lateral sclerosis. The invention equally concerns methods for identifying or screening compounds active in these diseases. The invention further concerns the compounds, genes, cells, plasmids or compositions useful for implementing the hereinabove methods. In particular, the invention describes the role of PDE4B in these diseases and its use as a therapeutic, diagnostic or experimental target.