INFLAMMATORY DEMYELINATING NEUROPATHIES Flashcards
What is Guillain-Barre syndrome?
Weakness of the limbs as a result of an acute polyneuropathy, a disorder affecting the peripheral nervous system. Usually triggered by an infection, which provokes immune-mediated nerve dysfunction.
What types of infections usually precede a diagnosis of Guillain-Barre syndrome?
Respiratory infection
Diarrhoea
What bacteria has been particularly associated with Guillain-Barre syndrome?
Campylobacter jejuni
How long after the infection do patient’s tend to start experiencing symptoms of Guillain Barre syndrome?
1-3 weeks
Which virus has been particularly associated with Guillain Barre syndrome?
Cytomegalovirus
What are the classical features of Guillain Barre syndrome?
Distal parasthesia (often with no sensory loss) Proximal or generalized weakness Facial weakness (often asymmetrical) Back pain Muscle pain Pain in neck and head
What is the time course of disease progression in Guillain Barre syndrome?
Symptoms ascend up lower limbs and body over days to weeks - often reaching a peak within 6 weeks
Plateau phase where disease persists but at a stable level
Recovery over many months
What is the pattern of affected muscles in Guillain Barre syndrome?
Symmetrical weakness in arm and legs, and possible neck involvement
50% have some cranial nerve involvement - leading to eye problems, problems using face muscles and dysphagia.
How long does the plateau phase of Guillain Barre syndrome tend to last for?
Median time is a week
What are the classical signs of Guillain Barre syndrome that would be elicited on examination?
Reduced power
Reduced or absent reflexes
What are the most worrying complications of Guillain Barre syndrome?
Weakness of breathing leading to respiratory failure, as well as infection.
Autonomic dysfunction leading to arrythmias
PE from not moving
What is the treatment for those with respiratory failure as a result of Guillain Barre syndrome?
Intubation of the windpipe and breathing support through mechanical ventilation, generally on an intensive care unit.
How might you be able to anticipate the need for ventilatory support in a patient with Guillain Barre syndrome?
Measurement of two spirometry-based breathing tests: the forced vital capacity (FVC) and the negative inspiratory force (NIF). An FVC of less than 15 ml per kilogram body weight or an NIF of less than 60 cmH2O are considered markers of severe respiratory failure.
Other than respiratory failure, what other serious complications do a proportion of Guillain Barre syndrome patients experience?
Autonomic dysfunction
What are the autonomic complications associated with Guillain Barre syndrome, affecting up to 60% of patients?
Severe blood pressure fluctuations Irregularities in the heart beat, sometimes to the point that the heart beat stops and requiring pacemaker-based treatment. Abnormalities in perspiration Changes in the pupillary response Urinary retention Constipation
What is the proximal variant of Guillain Barre syndrome?
Miller-Fisher syndrome
What is affected in Miller-Fisher syndrome?
This is a variant of Guillain Barre, affecting the more proximal muscles such as ocular muscles, muscles associated with areflexia and ataxia.
How would you diagnose Guillain Barre syndrome?
Usually a clinical diagnosis
Supported by slowed conduction velocity studies
Raised CSF protein
Normal CSF cell count or mild lymphocytosis
What antibodies will patients with Miller-Fisher syndrome have?
Anti-GQ1b ganglioside antibodies
What is the differential diagnosis for someone showing the signs and symptoms of Guillain Barre syndrome?
Poliomyelitis
Myasthenia gravis
Botulism
Primary muscle disease
How do you treat someone with Guillain Barre syndrome?
Recovery is usually spontaneous as long as the patient is monitored and maintained well enough - by the MDT team Constant monitoring of heart and lung function is necessary - often in ITU Pain management Plasmapheresis Intravenous immunoglobulin (IVIg)
Are steroids used in the management of Guillain Barre syndrome?
Steroids have not been shown to be particularly successful in treatment of Guillain Barre syndrome.
What is the mortality rate of Guillain Barre syndrome and what is this associated with?
5% - associated with inadequate ventilatory support, arrythmias, as well as complications of immobility (infection, PE).
At what point do we no longer classify an inflammatory demyelinating neuropathy as Guillain Barre syndrome and what do we call it?
8 weeks
Chronic inflammatory demyelinating polyradiculoneuropathy
What are the clinical features of chronic inflammatory demyelinating polyradiculoneuropathy?
Symmetrical weakness (both proximal and distal)
Sensory loss
Parasthesia
Which muscles are more commonly affected by chronic inflammatory demyelinating polyradiculoneuropathy?
Arms
Legs
Neck
(NOT facial muscles)
How could the pattern of sensory loss in inflammatory demyelinating neuropathies be described?
Glove and stocking
What will examination of the CSF reveal in someone with chronic inflammatory demyelinating polyradiculoneuropathy?
High protein
Normal cell count
Are steroids used in the treatment of chronic inflammatory demyelinating polyradiculoneuropathy?
Yes, unlike in Guillain Barre syndrome.
What is the treatment for someone newly diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy?
Management must always involve the MDT Prednisolone Plasmapheresis Intravenous immunoglobulin Immunosuppressants - eg Rituximab, cyclophosphamide or cyclosporins, azathioprine
What is multifocal motor neuropathy?
Lower motor neuron variant of motor neuron disease, characterised by progressive, asymmetrical weakness without sensory involvement. Rare disease.
What are the antibodies associated with multifocal motor neuropathy?
Anti-GM1 ganglioside antibodies
What is the treatment for multifocal motor neuropathy?
Intravenous immunoglobulins