Motor neuron disease

Question 1

MND signs

Answer 1

No sensory/sphincter loss
Never affects eye movements
Characterised by selective loss of neurons in motor cortex, CN nuclei and anterior horn cells
UMN + LMN signs
Frontotemporal dementia in 25%

Question 2

MND clinical patterns

Answer 2

Amyotrophic lateral sclerosis - combined UMN/LMN
Progressive bulbar palsy - CN IX-XII
Progressive muscular atrophy - LMN only with distal muscle groups affected first
Primary lateral sclerosis (rare) - mainly UMN signs, spastic leg weakness + pseudobulbar palsy

Question 3

MND prognosis

Answer 3

<3 yrs post onset in 1/2 of pt

Question 4

MND management

Answer 4

Riluzole (glutamate release inhibitor, NMDA antagonist) is only medication

Propantheline/botox for excess saliva
Blend food for dysphagia
Orthotics/physio for spasticity

Communication help
Palliative care

Question 5

Bulbar vs pseudobulbar palsy

Answer 5

Bulbar is CNIX-XII in medulla affected (LMN lesion)

Pseudobulbar is corticobulbar tracts above mid-pons (UMN lesion) affected

Question 6

El Escorial diagnostic criteria ALS

Answer 6

Definite: LMN+UMN in 3 regions
Probable: LMN+UMN in 2 regions
Probable with lab support: (LMN+UMN in 1 region/UMN in 1+ regions) + EMG shows denervation in >1 limb
Possible: LMN+UMN in 1 region
Suspected: UMN or LMN in 1+ regions