Motor Neuron Disease Flashcards
What is motor neuron disease?
A group of progressive and fatal conditions where motor neurons stop functioning.
Is sensation affected in MND?
No - only motor is affected
What is the most common form of MND?
ALS - amyotrophic lateral sclerosis
What are the other forms of MND?
Progressive bulbar palsy
Progressive muscular atrophy
Primary lateral scleorosis
Which motor neurons does ALS affect?
Upper and lower motor neurons
What is the aetiology of MND?
Most cases are sporadic but there are genetic components.
What are 3 risk factors for developing MND?
Smoking
Pesticides
Heavy metal exposure
Which motor neurons does progessive bulbar palsy affect?
Upper and lower motor neurons
Which motor neurons does progressive muscular atrophy affect?
Only lower motor neurons
Which motor neurons does primary lateral sclerosis affect?
Only upper motor neurons
What type of patient typically presents with MND?
Middle to late middle aged male patient
What are the classical symptoms of MND at presentation?
Asymmetrical weakness - typically in the upper limb first
Slurred speech
Fatiguability
Tripping over
Clumsiness
Wasting of muscles
What are the UMN signs?
Hypertonia
Hyperreflexia
Spasticity
Positive babinski sign
What are the LMN signs?
Hypotonia
Hyporeflexia
Fasciculations
Muscle atrophy
What investigations can be performed in the diagnosis of MND?
EEG
EMG
MRI brain and spine
ACh and MuSK antibodies
Lumbar puncture
Blood tests
What types of cells die in ALS?
Anterior horn cells and motor cortex neuronal cells
What features on history would point away from MND?
Sensory loss
Involvement of ocular muscles
What is the only disease modifying treatment for MND?
Riluzole
What does riluzole do?
Slows down the progression of ALS and prolongs life by a few months
What other management options are involved in MND?
Analgesia
Botox injections
Baclofen injections
Anticholinergics for drooling
NG/PEG tube
Advance care planning
Psychological support
Cough assist machines
Voice banking
What are the differentials of MND?
Myasthenia Gravis
Malignancy
Stroke
Motor neuropathy
MS
Disc prolapse
Which type of MND has the best prognosis?
Progressive muscular atrophy
Which type of MND has the worst prognosis?
Progressive bulbar palsy
What type of dementia is associated with motor neuron disease?
Fronto-temporal dementia
What nutritional support is preferred in MND?
PEG feeding
