Motor Neurone Disease Flashcards
what is Motor neurone disease
neurodegenerative disorders characterised by selective loss of neurons in motor cortex, cranial nerve nuclei and anterior horn cells
what differentiates MND from MS and polynuropathies
no sensory loss or sphincter disturbances
what differentiates MND from myasthenia gravis
MDN never affects eye movements
what clinical features do you find in MND
muscle weakness
problems with speech, swallowing and breathing
UMN and LMN
general pattern of onset of MND
focal onset
general spread
final generalized paresis
UMN lesion signs
increased tone hyper-flexia extensor plantar responses spastic gait exaggerated jaw-jerk slowed movements weakness of flexors in legs, extensors in arms)
LMN lesion signs
muscle wasting
weakness
fasiculations
absent/reduced deep tendon reflexes
what are the subtypes of MND
primary lateral sclerosis
amytrophic lateral sclerosis
progressive bulbar palsy
progressive muscular atrophy
what is the most common subtype of MND
amytrophic lateral sclerosis (ALS)
what condition is linked with ALS
Pick’s disease - frontotemporal dementia
are UMN and LMN features both present in ALS
yes
ALS pathology
loss of motor neurones in motor cortex + anterior horn cells
clinical features of ALS
UMN signs in legs (weakness of flexors)
LMN signs in arms wasting (painless) - e.g. thenar group
asymmetrical
diagnostic criteria for ALS
definite ALS - UMN + LMN signs in bulbar and at least 2 spinal regions
OR
UMN + LMN in 3+ spinal regions
Investigations for ALS
neurophysiology - EMG with evidence of fasiculations
MRI brain and spine - exclude alternative
CK levels - exclude myopathy
