Instead, certain potential risk factors for chronic pain like peripheral neuropathy, or preexistent chronic back pain as well as neuromyotonia tended to occur more frequently in patients with anti-Caspr2 autoantibodies and pain, arguing in favor of hyper-excitability, preexisting sensitization and/or decreased pain thresholds to play a role in pain induction. This evidence concerns the gene CNTNAP2 and Isaacs syndrome.