Motor neurone disease Flashcards
What is motor neurone disease
A devastating condition causing degeneration of the motor neurones, causing progressive weakness and death
What usually causes death in MND?
Respiratory failure or aspiration
Describe the aetiology of MND
50-75 y/o
ALS more common in non-Caucasian populations
What is the median survival after symptom onset in MND?
3 years
What causes MND?
The reason for it is unknown
What conditions are found under the term MND?
ALS
PLS
Progressive bulbar palsy
PMA
What are some benign variants of ALS?
Flail arm syndrome
Flail leg syndrome
(These will eventually progress into ALS)
What is the most common form of MND?
ALS - Amyotrophic Lateral Sclerosis
What does ALS stand for?
Amyotrophic Lateral Sclerosis
What does PLS stand for?
Primary Lateral Sclerosis
What does PMA stand for?
Progressive muscular atrophy
Describe the pattern of disease in ALS
Classic paraneoplastic presentation with simultaneous involvement of upper and lower motor neurones, usually in one limb, spreading gradually to other limbs and trunk muscles
What is split hand syndrome?
Preferential wasting of thenar group - a typical pattern of atrophy seen in ALS
Describe the pattern of disease in in progressive muscular atrophy (PMA)
Pure lower motor neurone presentation with weakness, muscle wasting and fasciculations, usually starting in one limb and gradually spreading to involve other adjacent spinal segments
Describe the pattern of disease in progressive bulbar and pseudo bulbar palsy
The lower cranial nerve nuclei and their supranuclear connections are initially involved, affecting the tongue, facial and pharyngeal muscles
How does progressive bulbar and pseudo palsy present?
Dysarthria
Dysphagia
Nasal regurgitation of fluids
Choking
Hypo/Hyper sialorrhoea
Wasting of the tongue and pharynx
Describe the pattern of disease in primary lateral sclerosis (PLS)
Confined to upper motor neurones, causing a slowly progressive tetraparesis and pseudobulbar palsy
What are some common presentations of MND?
Muscle weakness and possible speech and swallow problems
UMN and LMN signs without sensory signs
Focal onset and continuous spread
What is MND catabolism?
Loss of weight in MND despite normal eating - Cause unknown
What are some UMN signs of MND?
- Weakness or paralysis
- Spasticity
- Increased muscle tone (Hypertonia)
- Over-responsive reflexes (Hyperreflexia)
- Emotional lability
- Positive Babinski sign
What is meant by a positive Babinski sign?
When the bottom of the foot is stroked, instead of the toes curling in, the big toe extends up and the other toes fan out
Wha are some LMN signs of MND?
- Weakness or paralysis
- Decreased or absent muscle tone (Hypotonia or atonia)
- Decreased or absent reflexes (Hyporeflexia or areflexia)
- Involuntary muscle twitches (Fasiculations)
- Muscle atrophy
What are some red flag symptoms of respiratory failure in MND?
- Breathlessness
- Orthopnea
- Recurrent chest infection
- Disturbed sleep
- Non-refreshed sleep
- Nightmares
- Daytime sleepiness
- Poor concentration
What is meant by emotional lability in UMN MND?
Inappropriate crying or laughing
How is a diagnosis of MND made?
Mainly clinical diagnosis
Electrophysiology
Possible neuroimaging and lab studies
What are some on-going management strategies required in MND?
- Assessment and coordination of care
- Communication - SALT, AAC
- Nutrition - Gastrostomy, dieticians
- Respiratory - Assessment, home ventilation
What drug is the only drug licensed for MND?
Riluzole
What is riluzole?
A sodium-channel blocker that inhibits glutamate release, giving patients an extra 3 months of life
Why do most patients not choose to take riluzole?
- This will give the patient an extra 3 months of life, however, this will be during the end of their life, when they are in their worst state
- It also causes lethargy, sickness and possible cognitive impairment
Symptomatic treatment - Sialorrhoea
Hyoscine/buscopan
Glycopyrronium
Botox
Suction
Symptomatic treatment - Nutritional support
Supplements/thickeners
Liquid drug preparations
Symptomatic treatment - Bulbar dysfunction
Early communicator
Nutritional support
Care for upper respiratory tract
Symptomatic treatment - Limb dysfunction
Washing
Dressing
Feeding
Turning in bed
Mobility aids/hoists often necessary
Symptomatic treatment - Muscle cramps
Quinine
Baclofen
Symptomatic treatment - Muscle spasms
Baclofen
Tizanidine
Dantroline
Gabapentin
Symptomatic treatment - Emotional lability
Sometimes treated with antidepressants
