Compare and  contrast the  clinical  and  diagnostic  features of ascending  polyneuritis (Guillain Barre Syndrome), myasthenia gravis and motor neurone disease.

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This could be answered using a table format. Suggestions include the following:

ascending,
polyneuritis

myasthenia
gravis

motor neurone
disease

weakness

yes

yes

yes

reflexes

absent

present

May be increased (eg. amyotrophic lateral sclerosis)

characteristic distribution

ascending
symmetrical

Eyes & cranial
nerves

asymmetrical`

progression

acute and
recovery

relapsing

progressive

fatigue

no

characteristic

no

fasiculation

no

no

characteristic

increased CSF protein

yes

no

no

UMN signs present

no

no

May be present(eg. amyotrophic lateral sclerosis)

sensory features

often dysthesia
+ pain

no

no

pain

May be
present

no

no

delayed nerve conduction

yes

no

no

fade + post tetanic facilitation

no

yes

no

‘jitter’ on EMG

no

no

yes

response to anticholinesterases

no

yes

no

response to plasmapheresis

May occur

yes

no

Discussion

Approach to the ICU patient with generalised weakness is discussed elsewhere.

This table is a detailed version. The features listed by the college here have been incorporated into the greater table in the abovelinked summary ("Causes of Weakness in Intensive Care Patients ")

In short:

  • Only Guillain-Barre will have delayed nerve conduction, increased CSF protein and sensory features
  • Only myasthenia will have characteristic fatiguability, and will respond to anticholinesterase treatment (or plasmapheresis)
  • Only motor neuron disease will have increased reflexes, and will be assymetrical.

References

References

Oh's Intensive Care manual:

 

Chapter   51   (pp. 568)  Acute  cerebrovascular  complications by Bernard  Riley  and  Thearina  de  Beer

 

Chapter   57   (pp. 617)  Neuromuscular  diseases  in  intensive  care by George  Skowronski  and  Manoj  K  Saxena

 

Reeves and Swenson have an excellent online textbook chapter (12) entitled "Evaluation of the Patient with Weakness"