Motor neurone disease Flashcards
Where would you find upper motor lesion and lower motor lesions
Features of Upper motor neurone lesion
Upper motor neuron lesion are lesions anywhere from the cortex to the descending tracts.
Muscle weakness and decreased control - plegia
+
Poor balance
UP UP UP:
Hyperreflexia
hypertonia ~ Rigidity
Spasticity /
Ankle Clonus +
More disuse - disuse muscle atrophy
NO tongue fasciculations
+ve Babinski’s sign
Dyasrthia and dyshagia
Normal on nerve conduction studies
Features of lower motor neurone lesions
Lower motor neuron lesions present from from the anterior horn of the spinal cord, peripheral nerve, neuromuscular junction, or muscle.
Muscle weakness- plegia
Down down down
Flaccidity/ clonus -
Hypotonia
Hyporeflexia
Babinski -ve
+
Denervation atrophy
Tongue fasciculations
+ Dysarthia and dysphagia
Abnormal nerve conduction studies
TABLE UMN VS LMN
What is motor neurone disease?
Group of neurodegenerative disorders affecting motor neurones.
Rarely presents before 40 years old
HAS NO Eye sx (MS, MG) or sensory Sx(MS)
What is the general pathogenesis underlying motor neurone diseases ?
Genetic association / trauma - initiates inflammation = proliferation of glial cells/recruitment of other inflammatory mediators/ release of cytokines/chemokines -> neuronal damage = progressive loss
RF of motor neurone disease?
male
SOD-1 gene muatation
Age
What are the most common motor neurone diseases?
Amyotrophic lateral sclerosis
Progressive bulbar palsy
Primary lateral sclerosis
Progressive muscular atrophy
What are the features of Amyotrophic lateral sclerosis ALS
Most common motor neurone disaease 50%
Mix UMN/LMN signs
Associated with superoxide dismutase SOD1 GENE
Assymetrial onset
Can progress to bublar palsy
How would ALS present?
LMN/UMN signs and sx
Assymetrical presetntaton
LMN sx usually predominates e.g weakness, atrophy, fasciculations
Onset in limb is typical: foot drop/ wrist drop/ gait/ excess fatigue
+
Cognitive sx - ^% association with frontl-temporal dementia
Bulbar onset - dyarthira, dysphagia
What are the features of progressive bulbar palsy?
Affects the suprabulbar nuclei and cranial nerves, producing speech and swallow issues
Worst prognosis
Phargyngeal muscle weakness - diffculty talking, chewing , swallowing
Brisk jaw reflex
Dysarthia
Dysphagia
What are the features of primary lateral sclerosis?
UMN signs: predominantly affects the corticospinal tracts
What are the features of primary muscular atrophy?
Progressive muscular atrophy:
LMN signs: predominantly affects the anterior horn cells
Muscle wasting
Best prognosis
What is ABSENT IN MND?
How is MND investigate?
Genetic testing
Electromyography
Nerve conduction studies
MRI spine - exclude other ddx
Blood - exclude other reasons (Ab-AchR ~MG, Ab-CaR~LE)
El escorial criteria:
1- Presence of LMN (nerve conduction)
2- Presence of UMN (clinical examination)
+progressive spread of sx
+ Absence of evidence of other disease (Neuroimaging)
