Motor Neurone Disease Flashcards
What is motor neurone disease
an untreatable and rapidly progressive neurodegenerative condition resulting in progressive muscle weakness and wasting
What is the average MND survival time
3 years
How many cases of MND are familial
10 percent
What type of signs are seen in MDN
Both upper and lower motor neurone signs without sensory problems
What is the most common site of onset for MND
70 percent begin in the extremities
25 percent bulbar, 2 percent thoracic
Does the disease usually begin in the upper or lower motor neurones
usually lower -90 percent
Other than motor problems, what other problems may occur in someone with MND
frontal/cognitive deficits
What are the four main clinical patterns of MND? - please note these usually merge as the disease progresses
ALS - amyotrophic lateral sclerosis
Progressive muscular atrophy
Progressive bulbar and pseudobulbar palsy
Primary lateral sclerosis
What is the features of the bulbar varient
Affects 25 percent of patients
More common in woman and in those ages 60-80
always generalises into ALS
What is the pathological mechanisms of the bulbar varient
Lower cranial nerve nuclei and their supranuclear connection are initially involved.
How would the bulbar variant usually present
dysarthria
dysphagia
nasal regurge
What is ALS
‘classic’ MND
presents with upper and lower motor neuron signs in one limb which then gradually progresses to other limbs and the trunk
What is an unusual but important form of MND that can be easily missed?
thoracic
may present with dypsnoe at rest, pneumonia etc
What is progressive muscular atrophy?
A rare variant of MND only affecting the lower motor neurons
Can sometimes only by contained to one limb eg flail arm/leg syndrome
What is clinically important about PMA
better prognosis
What is primary lateral sclerosis
another rare form of mnd which only affects the upper motor neurones
what is Kennedy’s disease
an variant of SMA (spinobulbar muscular atrophy)
resulting in muscle cramps and progressive weakness due to degeneration of motor neurons in the brain stem and spinal cord
What signs would be classified as UMN signs
Spasticity
Babinski sign
BULBAR signs- exaggerated snout reflec, clinic jaw jerk, emotional lability, forced yawning
Cervica and lumbar region - clonic deep tendon reflexes, preserves reflec in a weak waster limb, Hoffman reflex, hyperrefelxia
Abdo- loss of superficial adbo reflexes
what Is a babinski’s signs
A positive babinskis test is dorsiflexion of the big toe when the sole of the foot is stimulated with a blunt instument
What is hoffmans reflex
The test involves tapping the nail or flicking the terminal phalanx of the middle or ring finger. A positive response is seen with flexion of the terminal phalanx of the thumb.
What are lower motor neurone signs
weakness fasiculations cramps hypotonicity atrophy hyporeflexia
What has now been ideniified as the patholgogical signature of MND
presence of TDP43 in 95 percent of cases