Motor Neuron Disease (MND) Flashcards
What is MND?
A group of neurodegenerative diseases, characterised by selective loss of neurons in motor cortex, cranial nerve nuclei and anterior horn cells
Loss of neurons in the motor cortex results in what sign?
UMN signs
Loss of neurons in cranial nerve nuclei results in what sign?
Mixed UMN + LMN signs
Loss of neurons in anterior horn cells results in what sign?
LMN signs
How can you distinguish MS and polyneuropathies from MND?
MND doesn’t have sensory loss or sphincter disturbance
How can you distinguish MND from myasthenia gravis?
MND never affects eye movements
What are upper limb symptoms of MND? (3)
- Reduced dexterity
- Stiffness
- Wasting of intrinsic muscles of hand
What are lower limb symptoms of MND? (3)
- Stumbling gait
- Tripping
- Foot drop
What are bulbar (cranial nerve IX, X, XI, XII) symptoms of MND? (3)
- Slurred speech
- Hoarseness of voice
- Dysphagia
What are the overall symptoms of MND? (2)
- Muscle atrophy
- Spasticity
How does amyotrophic lateral sclerosis (ALS) present?
UMN + LMN signs
How does progressive bulbar palsy (PBP) present?
UMN + LMN + cranial nerve IX, X, XI, XII signs
How does progressive muscular atrophy (PMA) present?
LMN signs only
How does primary lateral sclerosis (PLS) present?
UMN signs only (no cognitive decline)
How would you investigate MND? (5)
- Bloods: raised creatinine due to muscle destruction
- Electromyography: assesses denervation of muscles
- Nerve conduction studies: rule out motor neuropathies
- LP: exclude inflammatory causes
- MRI: exclude structural causes
