MOTOR NEURONE DISEASE Flashcards
What is motor neurone disease?
A neurodegenerative condition that affects the brain and spinal cord
Characterised by degeneration of primarily motor neurones, leading to muscle weakness
Unknown cause
Types of motor neurone disease?
Amytrophic lateral sclerosis - 50%
Primary lateral sclerosis
Progressive muscular atrophy
Progressive bulbar palsy
What is the progressive bulbar palsy subtype characterised by?
Rapidly progressive
The initial insult is on bulbar motor cranial nerves - wasting/weakness of tongue, muscles of chewing/swallowing and facial muscles, diffiuclty speaking, drooling
Worst prognosis
What is the progressive muscular atrophy subtype characterised by?
Initial degeneration is of the anterior horn cells
Manifests with progressive lower motor neurone signs only
Typically affects the distal muscles before the proximal
Note that over time UMN may be involved and diagnosis changes to ALS
Best prognosis
What is the primary lateral sclerosis subtype characterised by?
Uncommon form
Initially causes degeneration of first order motor neurones
Manifests with progressive UMN symptoms and signs only
Note that overtime LMN can become involved and diagnose changes to ALS
What is the amytrophic lateral sclerosis subtype characterised by?
Typically causes LMN signs in the arms and UMN signs in the legs - i.e. asymmetric limb weakness
Onetime it progresses and different areas of the body become involved e.g. speech, swallowing
Most common form of MND
Which subtype of MND has the best and which has the worst prognosis?
Best - progressive muscular atrophy
Worst - progressive bulbar palsy
Prognosis of progressive bulbar palsy?
Less than 1 year from diagnosis
Prognosis of amytrophic lateral sclerosis?
3-5 years
Prognosis of primary lateral sclerosis and progressive muscular atrophy?
About 10 years
What age is most common to get motor neurone disease?
55-79
Rare before 40
Diagnosis of motor neurone disease?
Clinical diagnosis
Some investigations are commonly done:
Nerve conduction studies will show normal motor conduction and exclude neuropathy
Electromyography shows a reduced number of action potentials with increased amplitude
MRI to exclude DDx of cervical cord compression and myelopathy
Management of MND?
No cure
Care focuses on maintaining functional ability and enabling people with MND and their family members to live a full and life as possible
Riluzole can prevent stimulation of glutamate receptors - prolongs life by about 3 months in ALS
Resp care e.g. NIV used at night - may increase survival by 7 months
PEG tube to support nutrition
What is motor neurone disease association?
A membership organisation that focuses on improving acces to care, research and campaigning for those people living with or affected by MND
What % of patients with MND die within 2 years?
50%
