BandersnatchF
Well-known member
An abnormal NCS can indicate quite a few disorders, none of which is ALS. Instead, it can mean trapped nerve (typically carpal tunnel, trapped ulnar nerve, or nerve in the leg) or other forms of general peripheral neuropathy. The reason it's done is that there are many things that twitching can indicate (neuromuscular irritation can have many causes, including "nothing at all"), and an NCS can help diagnose them.