Motor Neurone Disease Flashcards
what is motor neurone disease?
neurological condition of unknown cause which can present with both upper and lower motor neuron signs
what are the different disease patterns on motor neurone disease?
- amyotrophic lateral sclerosis
- progressive muscular atrophy
- bulbar palsy
what age do patients typically present with motor neurone disease?
> 40 years
what are the typical features of motor neurone disease?
- fasciculations
- absence of sensory signs/symptoms
- mixture of lower motor neuron and upper motor neuron signs
- wasting of the small hand muscles/tibialis anteiror is common
what will nerve conduction studies show in motor neurone disease?
normal motor conduction
what does electromyography show in motor neurone disease?
reduced number of action potentials with increased amplitude
how is motor neurone disease diagnosed?
clinical diagnosis
investigations performed to exclude alternative diagnosises:
* nerve conduction studies
* electromyography
* MRI
what condition is motor neurone disease associated with?
frontotemporal dementia
what is the clinical pattern of amyotrophic lateral sclerosis?
- 50% of patients
- typically LMN signs in arms and UMN signs in legs
- can be familial - mutation on chromosome 21 (codes for superoxide dismutase)
what is the clinical pattern of primary lateral sclerosis?
- UMN signs only
what is the clinical pattern of progressive musclar atrophy?
- LMN signs only
- affects distal muscles before proximal
- carries best prognosis
what is the clinical pattern of progressive bulbar palsy?
- palsy of the tongue, muscles of chewing/swallowing and facial muscles
- loss of function of brainstem motor nuclei
- carries worst prognosis
what type of MND carries the best prognosis?
progressive musclar atrophy
what type of MND carries the worst prognosis?
progressive bulbar palsy
what muscle group is spared in MND?
ocular muscles
