Its many mimics and grave prognosis make confident diagnosis essential

Advanced motor neurone disease is easily recognised. Progressively worsening dysphagia and dysarthria, and widespread wasting and weakness of the limbs with hyperactive reflexes in a corresponding wasted myotome in the absence of other neurological signs are unmistakable features. In North America patients with such symptoms and signs would be described as suffering from amyotrophic lateral sclerosis, while on both sides of the Atlantic the term motor neurone diseases (with an “s”) describes a heterogeneous group of sporadic and inherited disorders in which anterior horn cell degeneration forms part, or all, of the pathological picture.

More often patients present with incompletely developed disease, leading to a variety of specialist referrals: alteration in voice quality may lead to an ear, nose, and throat examination; foot drop may lead to an orthopaedic assessment and scrutiny of the lower back; and nocturnal breathlessness due to early intercostal and diaphragmatic weakness may lead to treatment for asthma. Initially signs may be confined to either the upper or lower motor neurones or the disease may be restricted to one anatomical area, such as the cervical segment. About a third of patients will begin their inexorable decline with symptoms of a bulbar or pseudobulbar palsy, a third with weakness in the upper limbs, …