Motor Neurone Disease Flashcards
What is MND?
Untreatable and rapidly progressive neurodegenerative condition
-Mainly clinical diagnosis
What does MND cause?
Progressive weakness and eventually death usually as a result of respiratory failure or aspiration
What is death from MND usually as a result of?
Respiratory failure
Aspiration
Most common type of MND?
Amyotrophic lateral sclerosis
What is MND AKA?
ALS
Lou Gehrig’s disease
Who gets MND?
- Males > females
- 90% sporadic and 10% familial
- Sporadic MND peaks at 50-75 y/o
Aetiology of MND?
Thought to be links with some genes such as
-C90RF72 gene
(which is linked to FTD suggesting conditions are interlinked)
Which MND is least common in non-Caucasians?
ALS
How does MND present?
- Muscle weakness and potentially problems with speech, swallow and breathing
- Upper and/or lower motor neurone signs without sensory problems
- Focal onset and continuous spread, finally generalized paresis
- Cognitive impairment
What are upper motor neurone signs?
- Pseudobulbar affect
- Increased tone
- Hyper-reflexia
- Extensor plantar responses
- Spastic gait
- Exaggerated jaw jerk
- Slowed movements
Lower motor neurone signs?
- Muscle wasting
- Weakness
- Fasciculations
- Absent or reduced deep tendon reflexes
- Muscle cramps
- Muscle hypotonicity
What is bulbar dysfunction?
Affects tongue muscles, facial muscles and pharyngeal muscles
What is spinal dysfunction?
- Variable
- Muscle wasting
- Loss of tone or contractures
- Consider: washing, dressing and feeding
- Mobility aids/hoists often necessary
Presentation of ALS?
- Flail arm syndrome
- Flail leg syndrome
- Focal distal spinal muscular dystrophy
- Kennedys disease (SMA Variant)
Presentation of emotional lability?
Inappropriate crying or laughing
Sometimes treated with anti-depressants
Types of MND?
- PLS: Primary Lateral Sclerosis
- ALS: Amyotrophic Lateral sclerosis
- PMA: Progressive muscular atrophy
- PBP: Progressive bulbar palsy:
What is PLS?
Primary Lateral Sclerosis
- UMN variant
- 1-3% of MND cases (less common)
- Good survival (>5 years)
What physiologically is PLS?
-Confined to UMN causing a slow progressive tetraparesis and pseudobulbar palsy
(Tetraparesis: 4 limbs muscle weakness)
What is ALS?
- Most common MND phenotype
- Upper and lower motor neurone features
- Poor survival (median 3-5 years)
- Muscle wasting and fasciculations
- Brisk reflexes
Presnetation of ALS?
Progressive Focal Muscle Weakness
- Muscle twitching
-Weakness in arm
-Wasting with muscle fasciculations due to spontaneous firing of abnormality large motor units formed by surviving axons branching to innervate muscle fibres that have lost their nerve supply
Initial presentation of ALS?
Weakness often starts in one limb and the spreads to other parts of body
-Cramps are common
What is PMA?
Progressive muscular atrophy
- Pure LMN presentations
- 10% of MND cases (Rare)
Presnetation of PMA?
- Weakness
- Muscle wasting
- Fasciculations that start in one limb and spread
What is progressive bulbar palsy?
- 1-2% MND cases
- Women > men (60-80 y/o)
- Limbs are preserved but symptoms in mouth
Mixed UMN and LMN but confined to the mouth is?
Progressive Bulbar Palsy
Progressive bulbar palsy mouth symptoms?
- Bulbar and wasted tongue
- Affected speech
- Tongue fasciculations with slow stiff tongue movements
- Choking
- Nasal regurgitation
- Dysarthria
- Dysphagia
Therapeutic interventions in progressive bulbar palsy?
- Early communicator
- Nutritional support
- Care for respiratory tract
How is MND diagnosed?
- Electrophysiology
- ALS: EI Escorial criteria
How is MND treated?
-Access to specialist MND services
Treatment plans of MND?
- Keyworker assessing needs and coordination of care
- Communication needs
- Nutritional needs
- Resp needs
- Riluzole
- Muscle cramps/spasms
Drug treatment for muscle cramps?
Quinine
Baclofen
Drug treatment for muscle spasms?
Baclofen
Tizanidine
Dantrolene
Gabapentin
what are the consequences of respiratory dysfunction?
- Weakness of resp muscles is one of the main causes of death in MND
- Resp management from diagnosis is vital
MND Resp red flags?
Breathlessness Orthopnoea Recurrent chest infection Disturbed sleep Non-refreshed sleep Nightmares Daytime sleepiness Poor concentration
When is non-invasive ventilation offered in resp dysfunction?
To support T2 Resp failure
Prognosis of MND?
3 years after symptom onset
Presentation of MND?
- Functional effects of muscle weakness eg loss of dexterity, falls or trips
- Speech/swallowing problems or tongue fasciculations
- Muscle problems: weakness, wasting, twitching, cramps, stiffness
- Breathing Problems: SOB, resp symptoms
- XSive daytime sleepiness, fatigue, early morning headache, SOB lying down
- Cognitive symptoms: Frontotemporal dementia, behavioural changes and emotional lability
- UMN and or LMN signs on examination
Diagnosis of MND?
Largely clinical
-No specific diagnostic tests but investigations can exclude other conditions
What does an EMG confirm? And what is that?
-Electromyography
Denervation of muscles due to degeneration of LMN
How long do most MND survive?
Most cases don’t survive past 3 years but some variants do better than others
What drug slows progression of MND?
Riluzole
What is riluzole?
Na+ channel blocker
-Inhibits glutamate release and slows progression slighlty by 3-4 months
Is riluzole popular?
NO
-Extra time added to life tends to be when you are most disabled
WHat is increased in MND?
Metabolic rate (wt loss expected)
What treats muscle spasms?
Baclofen
Management of MND?
- MDT approach
- Communication aids
- Dietician advice
- Gastrostomy
- Physiotherapy
- Baclofen for muscle spasms
- Non-invasive ventilatory support- BiPAP at night
