The diagnosis of motor neurone disease is often clinically difficult, and sometimes it is necessary to review a person for some time before the diagnosis becomes relatively certain. A general practitioner may suspect a neurological problem, and organise referral to a neurologist.
Several other neurological conditions resemble motor neurone disease, especially in the early stages, and need careful exclusion.
The diagnosis can be assisted through a range of tests, including some which eliminate other conditions. Nerve conduction studies (NCS) and electromyography (EMG) are often performed and may help in establishing the diagnosis. NCS involve analysing neural function by electrical stimulation of nerves and recording muscle activity. EMG consists of inserting a needle electrode into various muscles to measure their electrical activity.