Impairment and disability in 20 CIDP patients according to disease activity status. A principal component (PC) analysis and the correlations between the following scores were performed: Neurological Symptom Score; MRC sum score; Neurological Impairment Score; Hammersmith Functional Motor Scale; Inflammatory Neuropathy Cause and Treatment (INCAT). The INCAT disability score: A critical analysis of its measurement properties. Background: The INCAT (Inflammatory Neuropathy Cause and Treatment) disability score is a measure of activity limitation. It is used frequently as a primary endpoint in inflammatory polyneuropathy clinical trials. > Validated, point assessment used to evaluate disability in neuropathy research. > Patients evaluated on their ability to walk (scale of 0 to 5) and to perform certain arm functions (scale of 0 to 5) > Overall point INCAT disability score is the sum of arm and leg scores.