Neuro: Motor neuron disease Flashcards
What is meant by ‘motor neuron disease’?
Umbrella term for a range of neurological conditions in which the motor neurons stop functioning. It is progressive and ultimatley fatal.
What are the most common types of motor neuron disease?
ALS: Amyotrophic lateral sclerosis (ALS) - most common specific motor neurone disease
Progressive bulbar palsy: second most common and well-known specific motor neurone disease.
Specific types of motor neurone disease?
ALS (amyotrophic lateral sclerosis)
Progressive bulbar palsy
Progressive muscular atrophy
Primary lateral scelrosis
What muscles are primarily affected by progressive bulbar palsy?
Muscles of talking and swallowing
What is the very basic pathophysiology of motor neurone disease?
Progressive degeneration of both upper and lower motor neurones.
Sensory neurones are spared.
Risk factors for motor neurone disease?
Family history - genetics. Many genes linked with increased risk and 5-10% cases are inherited.
Smoking
Exposure to heavy metals
Exposure to cetrain pesticides
How does motor neurone disease typically present?
Typical patient: middle aged male (+/- affected relative)
Incidious, progressive
Weakness first noticed in upper limbs but progressive to trunk face and speech
Increased fatigue when exercising
Clumsiness, tripping, dropping things
Dysarthria (slurred speech)
Signs of motor neuron disease
Signs of LOWER motor neurone disease?
Muscle wasting
Reduced tone
Fasiculations
Reduced reflexes
Signs of UPPER motor neurone disease
Increased tone or spasticity
Hyperreflexia
Upgoing plantar responses
How is motor neuron disease diagnosed?
The diagnosis of motor neurone disease needs to be made very carefully. It is based on the clinical presentation and excluding other conditions that can cause motor neurone symptoms. It should only be made by a specialist when there is certainty. Unfortunately, the diagnosis is often delayed, which causes considerable anxiety and stress.
Pharmacological management of ALS?
Riluzole can slow progression and extend survival by a few months (initiated by specilists)
(Edaravone licesnced in US but not UK)
Non pharmacological management of motor neurone disease?
NIV at home to support breathing at night - improves survival and QOL
MDT involvement
End of life care planning
Advanced directives to anticipate disease progression
What is the most common cause of mortality in motor neurone disease patients?
Respiratory failure or pneumonia
What is the only liscenced treatment for motor neuron disease?
Riluzole
ALS presenting symptoms?
Weakness in muscles of the hands, arms or legs
Impairment in the use of arms and legs
Twitching and cramping of muscles, especially those in the hands and feet
Weakness in the muscles that control speech, swallowing or breathing
Slow or slurred speech (called dysarthria or “thick speech”) and difficulty in projecting the voice
ALS prognosis?
Life expectancy 2-5 years following onset of symptoms
Progressive Bulbar Palsy presenting symptoms?
Patients with progressive bulbar palsy initially develop symptoms restricted to the bulbar muscles. They usually present with a several-month history of progressive dysarthria with gagging, choking, and weight loss. The speech disturbance may lead to complete anarthria.
Progressive bulbar palsy prognosis?
Life expectancy 6 months to 3 years of onset of symptoms?
Between what ages does ALS typically present?
40-70 years
Between what ages are the typical onset of symptoms in progressive bulbar palsy?
50-70 years
First line treatments for muscle cramps in MND?
Quinine
Management of sialorrhoea in MND?
Consider a trial of antimuscarinic medicine as the first‑line treatment for sialorrhoea in people with MND
Consider glycopyrrolate as the first‑line treatment for sialorrhoea in people with MND who have cognitive impairment
Management of dysphaGIA in MND?
Modify diet and fluids
Involve salt
Reduce risks of aspirations
Reduce excess secretions
Early gastronomy
Management of respiratory failure in MND?
Address excessive secretions
NIV
CHest physio
Opioids
Consider benzos
What does hyperreflexia indicate?
Upper motor neurone lesion at a spinal level above that responsible for the reflex
What motor neurone signs occur in ALS and why
disease affecting the motor cortex and the anterior horn of the spinal cord, and thus characterised by the presence of both upper and lower motor neuron signs and symptoms
