Guillain-barre Syndrome

Question 1

…. syndrome is an acute, inflammatory polyneuropathy typically characterised by a progressive, ascending neuropathy resulting in weakness and reduced reflexes.

Answer 1

Guillain-Barré syndrome is an acute, inflammatory polyneuropathy typically characterised by a progressive, ascending neuropathy resulting in weakness and reduced reflexes.

Question 2

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).

Answer 2

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).

Question 3

.. jejuni is the most common identifiable trigger of GBS.

Answer 3

Campylobacter jejuni is the most common identifiable trigger of GBS.

Question 4

Campylobacter jejuni

Answer 4

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.

Question 5

Cytomegalovirus, Epstein-Barr virus, hepatitis E and mycoplasma pneumoniae have all been identified as triggers of what?

Answer 5

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.

Question 6

Acute inflammatory … … is the most common form of GBS.

Answer 6

Acute inflammatory demyelinating polyneuropathy is the most common form of GBS.

Question 7

Pathogenesis & variants of GBS

Answer 7

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.

Question 8

The most common form in European countries accounting for an estimated 90% of cases. AIDP presents with ‘classical’ symptoms of GBS: (3)

Answer 8

Progressive symmetrical weakness in limbs
Reduced or absent tendon reflexes
Reduced sensation (may not be clinically apparent to patient)

Question 9

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.

Answer 9

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.

Question 10

Miller Fisher syndrome (MFS)

MFS is a variant of GBS characterised by a unique presentation: (3)

Answer 10

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.

Question 11

Key investigations in suspected GBS include … (3)

Answer 11

electromyography, nerve conduction studies and lumbar puncture.

Question 12

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)

Answer 12

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.

Question 13

Bedside tests for suspected GB syndrome (5)

Answer 13

Vital signs 
Blood sugar
Pregnancy test (if indicated)
Stool culture (if indicated)
Urine porphobilinogen

Question 14

Bloods in suspected GBS

Answer 14

FBC
Renal function 
LFTS
CRP
Bone profile & Mg
HbA1c
Thyroid profile
B12/folate/thiamine
Blood borne virus screen 
Syphilis serology
Lyme serology

Question 15

What may CXR identify in GBS?

Answer 15

CXR: May identify bilateral hilar lymphadenopathy indicative of sarcoidosis (a condition that may cause neuropathies).

Question 16

An MRI spine conducted with gadolinium contrast in GB syndrome may show enhancement of…

Answer 16

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.

Question 17

Special tests in suspected GB syndrome (4)

Answer 17

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.

Question 18

Lumbar puncture in GB syndrome often shows …

Answer 18

Lumbar puncture: Albuminocytologic dissociation - a high CSF protein with normal CSF WCC - is commonly seen but depends on timing from onset of symptoms.

Question 19

Plasma exchange or IV immunoglobulin are used to hasten recovery of …

Answer 19

Plasma exchange or IV immunoglobulin are used to hasten recovery of Guillain-barre syndrome

Question 20

Respiratory failure in GB syndrome

Answer 20

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.

Question 21

What cardiovascular monitoring is important in GB syndrome?

Answer 21

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

Question 22

What prophylaxis is important in GB syndrome?

Answer 22

DVT prophylaxis: Unless contraindicated patients should receive lower limb stockings/flowtrons and LMWH prophylaxis.

Question 23

What pain is common in GB syndrome? And what is used to manage this pain?

Answer 23

Analgesia: Neuropathic pain is common and agents such as gabapentin and carbamazepine may be used.

Question 24

Measuring … is an important component of monitoring respiratory function

Answer 24

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.

Question 25

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

Answer 25

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.

Question 26

FVC monitoring - how often should this be monitored in GB patients?

Answer 26

Four hourly monitoring is recommended. This should be increased to 1-2 hourly if FVC < 20 ml/kg.

Question 27

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.

Answer 27

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

Question 28

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.

Answer 28

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.

Question 29

There are two main disease modifying treatments for GBS; what are they?

Answer 29

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..

Question 30

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 ….

Answer 30

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.

Question 31

GBS is described as a progressive post-infectious neuropathy that follows a … disease course.

Answer 31

GBS is described as a progressive post-infectious neuropathy that follows a monophasic disease course.

Question 32

GBS - clinical course and prognosis

Answer 32

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.

Question 33

Factors associated with a poorer prognosis of GB syndrome include: (4)

Answer 33

Old age
Preceding campylobacter jejuni infection
Rapid onset and severe presenting symptoms
Need for mechanical ventilation

Question 34

What is the one-year mortality for GB syndrome?

Answer 34

The one-year mortality is estimated at 3-7% with causes including respiratory failure, infection, cardiovascular dysfunction and pulmonary embolism.

Question 35

Clinical course of GB

Answer 35

Question 36

… criteria for GB syndrome

Answer 36

Brighton criteria

Can be supported by investigations - nerve conduction and LP

Question 37

Management of Guillain-Barré syndrome

Answer 37

May need ITU if resp failure

Question 38

Prognosis of GB syndrome

Answer 38

80% fully recover
15% some neuro disability
5% will die