What are the key clinical features to consider when diagnosing Motor Neurone Disease (MND) in a patient presenting with progressive weakness?

When diagnosing Motor Neurone Disease (MND) in a patient presenting with progressive weakness, key clinical features to consider include a combination of motor symptoms and possible cognitive or behavioural changes. The hallmark is progressive muscular weakness that may initially present as isolated and unexplained symptoms such as loss of dexterity, frequent falls or trips, muscle wasting, twitching (fasciculations), cramps, stiffness, and bulbar symptoms including speech and swallowing difficulties or tongue fasciculations. Respiratory symptoms like exertional shortness of breath or unexplained respiratory issues may also be early signs. Additionally, cognitive features such as behavioural changes, emotional lability, or frontotemporal dementia can be present in some cases, reflecting the broader spectrum of MND manifestations NICE NG42.

Clinically, the weakness in MND typically involves both upper and lower motor neurons, leading to a mixed pattern of muscle wasting, fasciculations, spasticity, and hyperreflexia, which helps differentiate it from other neuromuscular disorders. The pattern of weakness can be focal or multifocal and often progresses to involve multiple regions. Bulbar onset, characterized by speech and swallowing problems, is an important presentation associated with a poorer prognosis NICE NG42 Statland et al. 2015Orrell 2016Masrori & Van Damme 2020.

Early recognition of these features is critical, and unexplained progressive weakness with these associated signs should prompt urgent referral to a neurologist for further assessment. The diagnosis is clinical but supported by electrophysiological studies and exclusion of mimics. Awareness of cognitive and behavioural symptoms is also important as they may affect communication and decision-making capacity NICE NG42.