MND ☺️

Question 1

Presentation

Answer 1

On a spectrum of UMN, LMN involvement
-gradual loss of motor function which will eventually affect swallowing, breathing

UMN

• spasticity
• hyperreflexia
• Babinski
• weakness

LMN

• atrophy
• fasciculations - hyperexcitability of compensating motor neurones
• areflexia
• weakness

Thenar, 1st dorsal web, tibialis ant, tongue atrophy
-initially asymmetrical
speech slurring, clumsy hands, trips

Question 2

Investigations

Answer 2

Investigations support diagnosis and exclude mimics

• MRI brain/spine => exclude cord compression
• NCS => normal motor conduction
• EMG => fibrillations, positive sharp waves/large long APs
• FBC, renal/liver profile, B12/folate, HIV, CK

Needle electromyography - mixed pattern of acute and chronic denervation
acute - fibrillation, positive sharp waves - signs of fasciculations
chronic - large, long polyphasic waves

Question 3

Epidemiology

Answer 3

Men
Majority sporadic - 90% 
Genetic (SOD1, C9ORF72) - 10%
Onset from 50+
Medial survival 24-50months

Question 4

Management
-disease modifying
-symptomatic
Prognosis

Answer 4

Disease modifying - riluzole

Symptomatic - with support from palliative care

• labile emotions - nuedexta
• D+A - citalopram, mirtazapine
• cramps - quinine
• spasticity - baclofen
• drooling - hyoscine, atropine (anticholinergics)

Resp care - BIPAP at night

Poor prognosis - 1/2 die in 3 years

Question 5

Pathophysiology

Answer 5

TDP43 cytoplasmic aggregation in motor neurones

On the spectrum with FTD
Progressive motor unit loss

Question 6

Characteristics of ALS
Characteristics of PLS
Characteristics of PMA
Characteristics of PBP

Answer 6

ALS - Most common
-LMN, UMN involvement

PLS - Mainly UMN
PMA - Mainly LMN

Tongue, masticators, swallowers, facial palsy

Question 7

History findings

Answer 7

Progressive weakness in multiple body regions
Initially asymmetrical
-slurred speech
-clumsy hands
-foot drop (tibialis ant involvement)
-few sensory changes

Fasciculations
Cramps
Ataxia
Falls
Labile emotions
Weight loss

Question 8

Differentials

• LMN mimics
• UMN mimics

Answer 8

Very few conditions cause mixed UMN/LMN damage within same body region

• spinal lesion - LMN at level, UMN below
• VitB12 deficiency
• neurosyphyllis

LMN mimics
Structural => MRI spine
-spine tumour/degeneration
AI  => AChR AB, CK
-myasthenia gravis
Infective => serology
-HIV
Metabolic => B12 blood test
-Vit B12 deficiency

UMN mimics
Vascular => Head MRI
-stroke
Infective => serology
-neurosyphilis

Question 9

Progression of disease

Answer 9

1st region involvement
2nd region involvement
3rd region involvement
Nutritional and respiratory failure
Death

Linear decline can be tracked with ALS
-biomarkers of decline - motor unit numbers
Functional Rating Scale

Question 10

Diagnosis

Answer 10

Clinical but takes 1 year for diagnosis to be made

No of body regions with UMN and LMN impairment
1 - possible
2 - probable
3 - definite
Assess bulbar, resp, cervical and lumbar motor