Guillain-barre Syndrome Flashcards
…. syndrome is an acute, inflammatory polyneuropathy typically characterised by a progressive, ascending neuropathy resulting in weakness and reduced reflexes.
Guillain-Barré syndrome is an acute, inflammatory polyneuropathy typically characterised by a progressive, ascending neuropathy resulting in weakness and reduced reflexes.
GBS is a rare neuropathy classically presenting with progressive … … weakness. The majority of patients have history of a preceding illness (typically gastroenteritis or flu-like illness).
GBS is a rare neuropathy classically presenting with progressive lower limb weakness. The majority of patients have history of a preceding illness (typically gastroenteritis or flu-like illness).
.. jejuni is the most common identifiable trigger of GBS.
Campylobacter jejuni is the most common identifiable trigger of GBS.
Campylobacter jejuni
Campylobacter jejuni is a gram-negative rod and common cause of food poisoning and gastroenteritis. In adults it is thought to cause 25-50% of cases.
It appears to be related to more severe GBS when compared to other pathogens with slower recovery and greater risk of permanent disability.
Cytomegalovirus, Epstein-Barr virus, hepatitis E and mycoplasma pneumoniae have all been identified as triggers of what?
GB syndrome
Cytomegalovirus, Epstein-Barr virus, hepatitis E and mycoplasma pneumoniae have all been identified as triggers. It may follow a flu-like illness. More recently the Zika virus has been associated with the development of GBS. There appears to be an association in those with HIV.
Acute inflammatory … … is the most common form of GBS.
Acute inflammatory demyelinating polyneuropathy is the most common form of GBS.
Pathogenesis & variants of GBS
Acute inflammatory demyelinating polyneuropathy is the most common form of GBS.
GBS involves immune-mediated damage to peripheral nerves. One proposed mechanism is ‘molecular mimicry’ where antibodies generated in response to pathogens incorrectly cross-react with the bodies own cells.
The pattern of nerve involvement varies between variants of GBS. The myelin sheath is the target in AIDP (though the axon may be affected) whilst in AMAN and AMSAN axonal degeneration occurs.
The most common form in European countries accounting for an estimated 90% of cases. AIDP presents with ‘classical’ symptoms of GBS: (3)
Progressive symmetrical weakness in limbs Reduced or absent tendon reflexes Reduced sensation (may not be clinically apparent to patient)
Acute motor axonal neuropathy (AMAN)
AMAN is a form of GBS that results from axonal involvement typically following infection with …
It tends to progress more rapidly than AIDP and does not demonstrate sensory nerve involvement.
Acute motor axonal neuropathy (AMAN)
AMAN is a form of GBS that results from axonal involvement typically following infection with Campylobacter jejuni.
It tends to progress more rapidly than AIDP and does not demonstrate sensory nerve involvement.
Miller Fisher syndrome (MFS)
MFS is a variant of GBS characterised by a unique presentation: (3)
Ataxia
Areflexia
Ophthalmoplegia
Around 25% will also develop some weakness in the extremities. Up to 90% of patients will have antiganglioside antibodies (anti-GQ1B), a component of nerves.
Key investigations in suspected GBS include … (3)
electromyography, nerve conduction studies and lumbar puncture.
The diagnosis of GBS is suspected based on the clinical presentation. Investigations aim to confirm a diagnosis of GBS and exclude differentials. These include … (5)
The diagnosis of GBS is suspected based on the clinical presentation. Investigations aim to confirm a diagnosis of GBS and exclude differentials. These include lyme disease, sarcoidosis, thiamine deficiency, porphyria and neoplasms.
Bedside tests for suspected GB syndrome (5)
Vital signs Blood sugar Pregnancy test (if indicated) Stool culture (if indicated) Urine porphobilinogen
Bloods in suspected GBS
FBC Renal function LFTS CRP Bone profile & Mg HbA1c Thyroid profile B12/folate/thiamine Blood borne virus screen Syphilis serology Lyme serology
What may CXR identify in GBS?
CXR: May identify bilateral hilar lymphadenopathy indicative of sarcoidosis (a condition that may cause neuropathies).
An MRI spine conducted with gadolinium contrast in GB syndrome may show enhancement of…
MRI spine: Conducted with gadolinium contrast with which enhancement of the caudal equina nerve roots is often seen. Also useful to exclude alternate spinal pathologies.
Special tests in suspected GB syndrome (4)
Electrophysiology: Nerve conduction studies and electromyography can help confirm the diagnosis and differentiate between demyelinating and axonal forms.
Lumbar puncture: Albuminocytologic dissociation - a high CSF protein with normal CSF WCC - is commonly seen but depends on timing from onset of symptoms.
Antibodies: Anti-GQ1b, specific for Miller Fisher syndrome may be sent and is positive in around 90% of cases.
Spirometry: Used to monitor disease progression and involvement of respiratory muscles. Worsening results should trigger anaesthetic/ITU review for consideration of elective intubation.
Lumbar puncture in GB syndrome often shows …
Lumbar puncture: Albuminocytologic dissociation - a high CSF protein with normal CSF WCC - is commonly seen but depends on timing from onset of symptoms.
Plasma exchange or IV immunoglobulin are used to hasten recovery of …
Plasma exchange or IV immunoglobulin are used to hasten recovery of Guillain-barre syndrome
Respiratory failure in GB syndrome
Respiratory failure: Patients respiratory function should be regularly monitored with measurements of vital capacity, maximal inspiratory pressure and maximal expiratory pressure. Respiratory failure is not rare as the disease progresses and around 15-30% will need mechanical ventilation as part of their management. Patients with bulbar dysfunction or high aspiration risk may also need early intubation.
What cardiovascular monitoring is important in GB syndrome?
Blood pressure - may be labile with episodes of both hypo and hyper-tension seen
Both tachycardia and Brady-arrhythmias may occur also and telemetry should be considered
What prophylaxis is important in GB syndrome?
DVT prophylaxis: Unless contraindicated patients should receive lower limb stockings/flowtrons and LMWH prophylaxis.
What pain is common in GB syndrome? And what is used to manage this pain?
Analgesia: Neuropathic pain is common and agents such as gabapentin and carbamazepine may be used.
Measuring … is an important component of monitoring respiratory function
FVC
Measuring FVC is an important component of monitoring respiratory function. Measuring FVC should be based on weight and any significant fall should warrant referral to HDU/ITU for closer monitoring, of if significantly low, respiratory support.
Generally, an FVC < … ml/kg should warrant referral to HDU/ITU
If weight 55 kg: FVC < 1.1L, should warrant HDU/ITU referral
If weight 90 kg: FVC <1.8L, should warrant HDU/ITU referral
Generally, an FVC < 20 ml/kg should warrant referral to HDU/ITU
If weight 55 kg: FVC < 1.1L, should warrant HDU/ITU referral
If weight 90 kg: FVC <1.8L, should warrant HDU/ITU referral
Four hourly monitoring is recommended. This should be increased to 1-2 hourly if FVC < 20 ml/kg.
FVC monitoring - how often should this be monitored in GB patients?
Four hourly monitoring is recommended. This should be increased to 1-2 hourly if FVC < 20 ml/kg.
The Hughes disability score, also known as the GBS disability score, refers to a functional assessment of patients with GBS. It is graded 0-6 and used in some assessment and treatment pathways.
0 - Healthy state
1 - Minor symptoms, capable of running
2 - Able to walk 10 m or more without assistance but unable to run
3 - Able to walk 10 m across an open space with help
4 - Bedridden or chairbound
5 - Requiring assisted ventilation for at least part of the day
6 - Dead
The … disability score, also known as the GBS disability score, refers to a functional assessment of patients with GBS. It is graded 0-6 and used in some assessment and treatment pathways.
The Hughes disability score, also known as the GBS disability score, refers to a functional assessment of patients with GBS. It is graded 0-6 and used in some assessment and treatment pathways.
There are two main disease modifying treatments for GBS; what are they?
Intravenous immunoglobulin: Involves the peripheral infusion of immunoglobulin, the mechanism of action is not fully understood. As a blood product there is a risk though low of HIV, Hep B/C or CJD transmission. It is contraindicated in IgA deficient patients where it may cause anaphylaxis
Plasma exchange: Patients blood is removed, separated and the plasma removed and replaced. This removes circulating antibodies and other immune modulators..
Intravenous immunoglobulin: Involves the peripheral infusion of immunoglobulin, the mechanism of action is not fully understood. As a blood product there is a risk though low of HIV, Hep B/C or CJD transmission. It is contraindicated in IgA deficient patients where it may cause ….
Intravenous immunoglobulin: Involves the peripheral infusion of immunoglobulin, the mechanism of action is not fully understood. As a blood product there is a risk though low of HIV, Hep B/C or CJD transmission. It is contraindicated in IgA deficient patients where it may cause anaphylaxis.
GBS is described as a progressive post-infectious neuropathy that follows a … disease course.
GBS is described as a progressive post-infectious neuropathy that follows a monophasic disease course.
GBS - clinical course and prognosis
Typically symptoms develop rapidly over two weeks before plateauing, with recovery beginning around week four. Plasma exchange and IVIG have been shown to speed up recovery.
At 6-months around 80-85% of patients can walk unaided. Relapses are uncommon but affect up to 10% of patients with worsening of weakness seen.
Factors associated with a poorer prognosis of GB syndrome include: (4)
Old age
Preceding campylobacter jejuni infection
Rapid onset and severe presenting symptoms
Need for mechanical ventilation
What is the one-year mortality for GB syndrome?
The one-year mortality is estimated at 3-7% with causes including respiratory failure, infection, cardiovascular dysfunction and pulmonary embolism.
Clinical course of GB
… criteria for GB syndrome
Brighton criteria
Can be supported by investigations - nerve conduction and LP
Management of Guillain-Barré syndrome
May need ITU if resp failure
Prognosis of GB syndrome
80% fully recover
15% some neuro disability
5% will die
