Motor neurone disease (MND) has been in the spotlight recently courtesy of the film, ‘The Theory of Everything’. This summary produced by the MND Association with the RCGP aims to aid GPs in diagnosing this rare condition, and has been reproduced with kind permission of the MND Association.
Diagnosis of MND
Remember that MND can present at any age and presentation is usually asymmetrical.
Firstly, ask yourself: does your patient have one or more of the following symptoms?
70% present with limb features
- Focal weakness (painless with preserved sensation)
- Distal weakness
- Falls/trips from foot drop
- Loss of dexterity, e.g. problems with zips and buttons
- Muscle wasting
- Hands and shoulders
- Typically asymmetrical
- Muscle twitching/fasciculation
- No sensory features
25% present with these
- Dysarthria (painless progressive dysarthria: consider neurology rather than ENT referral)
- Slurred speech often when tired
- Quiet, hoarse or altered speech
- More often liquids first then solids
- Initially can be a sensation of catching in the throat or choking when drinking quickly
- Choking sensation when lying flat
- Excessive saliva
- Tongue fasciculation
- Weak cough
Rarely a presenting feature, usually occurs later
- Hard to explain respiratory symptoms (not explained by pulmonary or cardiac causes)
- Shortness of breath
- Excessive daytime sleepiness
- Early morning headache
- Weak cough and sniff
- Behavioural changes (apathy, lack of motivation)
- Fronto-temporal dementia (loss of empathy, loss of inhibitions, lack of motivation but not sad, or new problems with language)
- Emotional lability (not caused by dementia)
- Ask specifically about a family history of similar features
The following features do NOT support a diagnosis of MND:
- Bladder/bowel involvement
- Prominent sensory symptoms
- Double vision/ptosis
- Symptoms that improve
Secondly ask yourself: are these symptoms progressive?
If yes to both questions, this could be MND: refer to neurology and specifically query the diagnosis in the referral letter. Common causes of delay are initial referrals to either ENT or orthopaedics.
The MND Association has an enormous amount of useful information presented in a sensitive way.