Motor neurone disease Flashcards Preview

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Flashcards in Motor neurone disease Deck (15):
1

Signs of MND on examination

Inspection: Wasting and fasciculation, especially tongue fasciculation.
Tone: spastic.
Power: weak.
Reflexes: absent or brisk (mixed UMN and LMN signs in MND).
Sensation is Normal.

2

Completion of an MND exam

Speech: bulbar palsy - nasal speech. Pseudobulbar - hot potato speech.
Jaw-jerk: bulbar - absent, pseudobulbar - brisk.
Eye movements: MND does not involve the eyes.

3

Lesion difference between bulbar and pseudobulbar palsy

Bulbar palsy: Lower motor neurone lesion of CN9, 10 and 12.
Pseudobulbar palsy: Upper motor neurone lesion of CN9, 10 and 12.

4

Distinguishing bulbar versus pseudobulbar clinically

LMN (bulbar) = nasal speech + tongue fasciculating + wasting
UMN (pseudobulbar) = hot potato speech + increased jaw jerk + spastic

5

DDx for apparent MND

Cervical cord compression leading to myelopathy
Brainstem lesions
Polio: asymmetrical LMN paralysis
Mixed UMN and LMN signs:
"MAST"
MND
Ataxia, Friedrich's
SCDC (B12)
Taboparesis

6

Investigations for MND

Brain/cord MRI to exclude structural cause (cervical cord compression or brainstem lesion)
EMG: fasciculation
Lumbar puncture to exclude inflammatory cause (e.g. multiple sclerosis)

7

Diagnostic criteria for MND

Revised El Escorial Criteria (for ALS only)

8

General management for MND

MDT
Discussion of end-of-life decisions, e.g. DNAR, advanced directive

9

Medical management of MND

Riluzole is the only drug with proven benefit - prolongs lifespan by 3 months.
Symptomatic:
Drooling - hyoscine.
Muscle cramps - baclofen, quinine, diazepam.
Respiratory distress - opiates (palliative setting).
Depression - antidepressants.
Pain - analgesia.

10

Prognosis in MND

Most die within 3 years due to bronchopneumonia and respiratory failure.
Worse prognosis: elderly, female, bulbar involvement.

11

Types of MND

50% Amyotrophic Lateral Sclerosis
30% Primary Lateral Sclerosis
10% Progressive Bulbar Palsy
10% Progressive Muscular Atrophy

12

Pathophysiology of Amyotrophic Lateral Sclerosis

Corticospinal tracts affected - UMN and LMN signs + fasciculation

13

Pathophysiology of Primary Lateral Sclerosis

Loss of Betz cells in motor cortex - mainly UMN signs. Marked spastic leg weakness and pseudobulbar palsy. No cognitive decline.

14

Pathophysiology of Progressive Bulbar Palsy

Only affects CN9-12 - bulbar palsy

15

Pathophysiology of Progression Muscular Atrophy

Anterior horn cell lesion - LMN signs only. Distal to proximal. Better prognosis compared to ALS.