Motor Neuron Disease Flashcards
Motor neuron disease is a n________ disease, causing ___ and ___ signs
neurodegenerative
UMN and LMN
What is the main motor tract called?
Corticospinal tract
True or false: an UMN lesion causes hypotonia
False
UMN causes hypertonia, rigidity and spasticity
A LMN lesion causes hypotonia (flaccid and muscle wasting)
True or false: an UMN lesion causes hyperreflexia
True
What are fasciculations?
Muscle twitching due to an overactive nerve resulting in involuntary muscle movement
Are fasciculations present in an UMN or LMN lesion?
LMN
True or false: an UMN lesion gives a positive Babinski sign
True
What is Babinski sign?
Sole of foot is firmly stroked causing big toe to move upward and the other toes fan out
Normal reflex in infants (up to 2 y/o)
In adults, indicates problem with brain or spinal cord.
In an UMN lesion are the the flexor or extensor muscles in the arm more powerful?
Flexors
In an UMN lesion are the the flexor or extensor muscles in the leg more powerful?
Extensors
True or false: A LMN lesion can result in hyporeflexia, no fasciculations, positive Babinski sign and less power?
False
In a LMN lesion, get: hyporeflexia, fasciculations, negative Babinski sign and generally less power
If you see mixed UPN and LMN signs what could it be?
Motor neuron disease
What are risk factors for MND?
Male
Family history
SOD-1 mutation
Age
True or false: MND can cause paralysis of ocular muscles
False
Never affects eye muscles unlike in MS and MG (myasthenia gravis)
Does MND affect sensory function?
No. Sensory function can be affected in MS and polyneuropathies
After the idea of movement has begun in the association cortexes and pre-motor cortex and the UMNs have been activated in the motor cortex, where does the impulse travel next?
Down corticospinal tract with modulations at the cerebellum for fine tuning and basal ganglia to continue impulse.
What are 2 classifications of MND?
ALS (more common) and progressive bulbar palsy
What does ALS stand for?
Amyotrophic Lateral Sclerosis
Does ALS affect UMN, LMN or both?
Both
Does Progressive Muscular Atrophy occur in UMNs, LMNs or both?
LMN only
Is the degeneration of LMNs, generalised and progressive loss of muscle function
What is PLS (primary lateral sclerosis)?
Type of motor neuron disease. Weakness in voluntary muscle movement due to nerve cells degenerating in motor regions.
What is affected and in what order with primary lateral sclerosis?
Movements are slow and effortful first in legs, then body, trunk, arms, hands and bulbar muscles
Does Primary Lateral Sclerosis occur in UMNs, LMNs or both?
UMNs only
What is progressive bulbar palsy (PBP)?
Worst prognosis
Impaired function of lower cranial nerves that arise from brainstem
CN 9-12 affected
Difficulty chewing and swallowing, reduced gag reflex, nasal regurgitation, slurred speech, aspiration of secretions, dysphonia (hoarseness) and dysarthria
There is an increased chance of _____ failure with progressive bulbar disease
respiratory
What signs aren’t present in MND to help differentiate it from other neuro conditions?
No eye signs
No sensory signs
Cerebellar function fine
No Parkinson’s signs
How is MND diagnosed?
Mainly clinical
EMG (electromyography) shows fibrillation potentials due to degeneration of muscles with LMN dysfunction
How is MND managed?
Riluzole (anti-glutaminergic)
Supportive physio and breathing support
What are complications of MND?
Respiratory failure
Aspiration pneumonia
Swallowing failure
What is PMA (progressive muscular atrophy)?
A type of MND whereby there is degeneration of lower motor neurons only causing progressive loss of muscle function
What are some symptoms of Progressive Muscular Atrophy?
Muscle weakness and wasting in legs, arms, body and hands
Flail arm syndrome
Fasciculations
Difficulty breathing
