MOTOR NEURONE DISEASE Flashcards
Is motor neuron disease a disease of the upper or lower motor neurons?
Both
What are the five main types of motor neuron disease?
Amyotrophic lateral sclerosis Progressive bulbar palsy Primary lateral sclerosis Primary muscular atrophy Pseudobulbar palsy
Does motor neuron disease affect only the motor neurons?
No, it also affects the cognitive centres, cerebellar and extrapyramidal pathways, as well as sensory system in some cases.
What is the incidence of amyotrophic lateral sclerosis?
2 per 100,000
Is amyotrophic lateral sclerosis more common in men or women?
Men (2:1)
What is the mean age of onset of amyotrophic motor neuron disease?
60 years
What is the mean duration of survival post diagnosis of amyotrophic motor disease?
3 years
Does amyotrophic lateral sclerosis affect upper motor neurons, lower motor neurons or both?
Both
What are the classical signs of amyotrophic lateral sclerosis?
Wasting of intrinsic muscles of the hand Wasting and fasciculations of the legs Wasting and fasciculations of the tongue Brisk reflexes in the triceps, brachioradialis, knee and ankle and brisk jaw jerk reflex Extensor plantar reflex Dysarthria Dysphagia Increased tone
Is amyotrophic lateral sclerosis normally generalised or focal?
Focal
Is amyotrophic lateral sclerosis normally distal or proximal?
Distal
Is amyotrophic lateral sclerosis normally symmetrical or asymmetrical?
Asymmetrical
What are the features of ‘flail arm variant’ of motor neuron disease?
Symmetrical, proximal flaccid weakness of the arms, with sparing elsewhere.
What are the extra-motor features associated with motor neuron disease?
Cognitive impairment
Frontotemporal dementia
Does progressive muscular atrophy affect upper motor neurons, lower motor neurons or both?
Lower motor neurons predominantly but then progresses to involve upper motor neurons as well.
What are the signs associated with progressive muscular atrophy (PMA)?
Wasting
Weakness
Fasciculations
Tendon reflexes are usually preserved
Where does progressive muscular atrophy (PMA) usually start?
In the small muscles of the hands or feet. Asymmetric distribution
What does ‘bulbar’ refer to, in bulbar palsy?
The lower brainstem motor nuclei
Does progressive bulbar palsy affect the upper motor neurons, lower motor neurons or both?
Lower motor neurons
What are the classic clinical features associated with progressive bulbar palsy?
Prominent fasciculations of the tongue Wasting of the tongue Weak palate - nasal regurgitation Nasal voice Normal or absent jaw jerk
What are the classic clinical features associated with pseudobulbar palsy?
Spastic dysarthria (Donald-Duck voice) Dysphagia Hypersalivation Laryngospasm Emotional lability
What symptoms do 25% of motor neuron disease patients initially develop?
Bulbar signs
Do those who motor neuron disease patients, who have symptoms restricted to the tongue and muscles innervated by lower cranial nerves, have a better or worse prognosis than more generalised ALS? Why?
Those with progressive bulbar palsy and pseudobulbar palsy often have a worse prognosis because they are more at risk of aspiration. These patients often lose the ability to speak.
Does pseudobulbar palsy affect the upper motor neurons, lower motor neurons or both?
Upper motor neurons
Does primary lateral sclerosis affect the upper motor neurons, lower motor neurons or both?
Upper motor neurons
How is the diagnosis of primary lateral sclerosis made?
After the signs and symptoms of motor neuron disease have remained for three years as solely upper motor neuron.
Do patients with primary lateral sclerosis have a better or worse prognosis than other motor neuron disease patients?
Better
What is the gene associated with motor neuron disease?
Superoxide dismutase-1 (SOD-1)
What does electromyography of a patient with motor neuron disease show?
Fibrillation potentials and positive sharp waves - indicating presence of denervation in the muscles supplied by more than one spinal region.
What might a nerve conduction study in someone with motor neuron disease reveal?
Reduction in amplitude
What are the drugs used in the management of motor neuron disease?
Riluzole - a glutamate receptor antagonist
What effect on morbidity prognosis does riluzole have for motor neuron disease?
Nothing. It has no effect on disability but it increases survival by 2-3 months.
