Question 10 | Deranged Physiology

With respect to the Guillain Barre Syndrome (GBS):

Outline how you would distinguish between GBS and Critical Illness Polymyoneuropathy (CIP).
What are the current treatment options in GBS? Briefly outline the supporting evidence
What is the prognosis of GBS and what factors are associated with a worse outcome?

College Answer

	GBS		CIP
History and Examination	Recent GI or resp illness. Progressive bilateral symmetric paralysis. Subtypes can be more localized e.g. MF opthalmoplegia and ataxia. Sensory involvement is common. Areflexic. Autonomic involvement may be present		Always occurs in association with a critical illness in particular severe sepsis. May have an association encephalopathy in early stages. It is a symmetrical weakness. May have muscle tenderness, hyporeflexic, diminished distal sensation Not associated with autonomic involvement
Investigations Blood		Albuminocytologic dissociation in CSF. Identification of infection with campylobacter, mycoplasma, EBV,Varicella, CMV. Elevated csf IGG levels and possible serum antiganglioside antibodies		Elevated CK which may be transient.
Nerve conduction studies and EMG		When demyelinating form is present, you get a reduction in conduction velocity as well as reduction in CMAP. In axonal forms however it is only the distribution of the findings that helps determine the diagnosis.		A axonal neuropathy resulting in a decreased CMAP without a reduction in conduction velocity

Plasma exchange and IVIG are both better than no therapy in hastening recovery from an episode and are equally effective. No value in both being given routinely.

- - Up to 20% of patients are still significantly disabled at 6 months and 15% still have significant functional disability at 1 year.

- Recurrence rate is 7% with the mean interval between recurrences being 7 years.

The distinctions between GBS and CIPN:

CIPN is associated with a severe illness, whereas GBS is associated with a mild one.
CIPN does not have autonomic dysfunction, whereas GBS does.
CIPN will not have any specific CSF findings, whereas GBS will have raised CSF protein and perhaps even a monocytosis
CIPN nerve conduction studies will not show any decrease in conduction velocity, whereas in GBS the cardinal feature is decreased conduction velocity.

As for management, Oh's Manual recommends either plasma exchanges or IV immunoglobulin, but there is no benefit in giving both together.

An even better table than the CICM college answer is available in this 2006 article fom Respiratory Care; it is reproduced below.

Clinical Features and Laboratory Findings
Critical-Illness Polyneuropathy, Guillain-Barre´ Syndrome, and Critical Illness Myopathy
	Critical illness polyneuropathy	Guillain-Barre	Critical Illness Myopathy
Clinical setting	Sepsis Multiorgan failure Septic encephalopathy	Antecedent viral illness Surgery Campylobacter jejuni HIV	Neuromuscular blocking drugs Corticosteroids Asthma Organ transplant
Motor weakness	Generalised and distal	Generalised and ascending	Generalised and proximal
Reflexes	Diminished	Absent	Preserved but weak
Cranial nerve palsy	Rare	Common	Absent
Dysautonomia	Normal autonomic function	Frequent dysautonomia	Normal autonomic function
Sensory deficit	Distal	Normal sensation, or slightly altered	Normal sensation
CK level	Normal	Normal	Elevated
Nerve conduction	Reduced CMAP and SNAP amplitude (compound muscle action potentials and sensory nerve action potentials)	Marked slowing, conduction block	Reduced CMAP amplitude Normal SNAP amplitude
Needle EMG	Abnormal spontaneous activity Reduced recruitment Large polyphasic motor unit potentials (MUPs)	Abnormal spontaneous activity Reduced recruitment Normal MUPs (early in disease)	Minimal spontaneous activity Early recruitment Small polyphasic MUPs;
Direct muscle stimulation	Normal	Normal	Absent or reduced
Muscle biopsy	Neuropathic changes	Neuropathic changes	Myopathic changes Thick myosin filament loss Muscle fiber necrosis

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

Yuki, Nobuhiro, and Hans-Peter Hartung. "Guillain–Barré syndrome." New England Journal of Medicine 366.24 (2012): 2294-2304.

Jani, Charu. "Critical Illness Neuropathy." Medicine (2011): 237.