GPs have key role in managing motor neurone disease

Motor neurone disease (MND) is a rapidly progressive neurodegenerative condition. It affects people of all ages, but is more common with increasing age (especially over 50 years) and men are affected twice as often as women. The causes remain unknown, although around 5% of cases have a genetic basis. Survival is usually only three to five years from diagnosis. MND affects both upper and lower motor neurones, with variable contributions. The nerve involvement in MND usually has a focal onset, is asymmetrical, but tends to spread to adjacent regions of the body. If the affected region is in the legs, a common presenting feature is tripping, falls or foot drop. If it is in the arms there may be difficulty with fine tasks such as fastening buttons, or raising an arm, and if the cranial nerves are affected there may be slurring of speech, or difficulty swallowing. Key to the diagnosis is evidence of progression, and this may lead to some delay in considering and also confirming the diagnosis. When examining the patient, evidence of more widespread neuromuscular involvement should be looked for. In a patient with foot drop, and fasciculation of the tongue, MND would be a likely diagnosis. Upper motor neurone involvement may be readily determined by examining the reflexes. Brisk reflexes, in the arms, legs or jaw, in the context of features of lower motor neurone denervation are highly suggestive of MND. Suspicion of MND should lead to referral for a neurology opinion. The most useful investigation is likely to be EMG with nerve conduction studies, and probably MRI scan of relevant areas. Blood tests are arranged to screen for any other causative condition. Riluzole is a disease modifying drug licensed to extend the life of patients with MND. There is no treatment that will reverse, or halt, progression of the disease.