PNS - GUILLIÁN-BARRÉ SYNDROME

Question 1

Guillán-Barré Syndrome (GBS)

aka

Answer 1

Acute Inflammatory Demyelinating Polyneuropathy (AIDP)

Question 2

Guillán-Barré Syndrome (GBS) may be caused by

Answer 2

Post-viral: Respiratory and/or GI infections

• Mononucleosis
• Epstein-Barr virus
• Cytomegalovirus
• Campylobacter Jejuni enteritis
• Swine flu inoculation

Question 3

Pathogenesis of Guillán-Barré Syndrome (GBS)

Answer 3

Autoimmune attack of Schwann cells -> demyelination

Affects PNS from spinal nerve roots to distal termination of motor & sensory fibers

Inflammatory response results in macrophages & lymphocytes that strip myelin from PNS nerves

Question 4

Remyelination and GBS

Answer 4

Mediated by Schwann cells

Recovery time depends on whether axonal degeneration has occurred
80% w/ Segmental Demyelination only
-segmental is better - so most people recover pretty well

20% also suffer from Wallerian Degeneration

Recovery results in shorter internodes

Question 5

Disease progression of GBS

Answer 5

Acute progression w/ peak impairment in 3-4 wks
Followed by a plateau period w/ no change in function (2-4 wks)
Then followed by a recovery phase (months to years, proximal to distal)

less extreme more likely to recover fully

could die from respiratory reasons

Question 6

CIDP is

Answer 6

(Chronic Inflammatory Demyelinating Polyneuropathy) – aka Relapsing Remitting GBS:

• Characterized by repeated exacerbations of demyelination & denervation (means you have multiple times)
• Some consider this a separate entity from GBS

Question 7

Clinical Presentation of GBA

Answer 7

Rapid onset, ascending, symmetrical motor & sensory deficits w/ sparing of extraocular muscles

Weakness/paralysis of the legs ->arms -> respiratory muscles -> face

Loss of proprioception, but pain/temp sense remains intact usually

CN might be affected -> bulbar symptoms

Mechanical ventilation required (~30%)

Pain/Dysesthesias

LMN signs

Autonomic symptoms

Question 8

If CNs are affected with GBS what type of symptoms could someone have and examples

Answer 8

Impairment of function of the cranial nerves IX, X, XI and XII,
Oropharyngeal dysarthria & dysphagia, drooling, etc.

Question 9

GBS and Mechanical ventilation prognosis

Answer 9

Respiratory failure is the most common cause of mortality

Poor Prognosis

Question 10

Pain/Dysesthesias associated with GBS resolve

Answer 10

Paresthesias resolve first & (usually) quickly – self limiting, treatment w/ standard analgesics

associated w/ pressure areas or lengthening of long myelinated axons

Question 11

LMN signs and GBS

Answer 11

Flaccid paralysis

Areflexia

Question 12

Autonomic symptoms and GBS

Answer 12

Can result from the demyelination of preganglionic ANS fibers (part of PNS - LMN):
Cardiac arrhythmias, tachycardia

BP lability
Orthostatic hypotension (>50%)

Lack of thermoregulation

Question 13

Diagnosis of GBS

Answer 13

Required Evidence:

• Rapid onset of progressive ascending symmetrical weakness of 2 or more limbs
• Areflexia (muscles do not respond)
• Disease course < 4 weeks
• Exclusion of other causes (rule out fever, fever would mean something else)

Question 14

Supportive evidence of GBS

Answer 14

Supportive Evidence
Mild sensory involvement
Facial nerve or other cranial nerve involvement
Absence of fever
Lumbar puncture: elevated albumin levels in CSF w/o ↑ cell count (r/o infectious cause)
Electrophysiologic evidence of demyelination from EMG or NCV studies

Question 15

Medical Management of GBS

Answer 15

Intravenous Immunoglobulins (high doses)

Plasmapheresis

Methylprednisolone

Question 16

What are Intravenous Immunoglobulins

Answer 16

IVIg – MOA unknown, but possibly blocks macrophage & antibody binding

Better chance of fighting infection because it increases immune system

Question 17

Plasmapheresis and treatment of GBS

Answer 17

Plasma contains antibodies: plasma is replaced with “clean” plasma
Typically a 5-day treatment regimen

Question 18

Methylprednisolone and treatment of GBS

Answer 18

Steroid

-Efficacy is highly debatable

Question 19

Rehab Management of GBS in Acute phase

Answer 19

Respiratory support – mechanical ventilation, pulmonary hygiene (suction, assisted cough, etc)

Positioning to prevent contractures/pressure ulcers

Provide education/support to the pt/families

Question 20

Rehab Management of GBS in Later phase

Answer 20

Muscle strengthening – avoid overwork weakness

Respiratory training

Functional activity training

Endurance & aerobic training

Question 21

Prognosis for GBS

Answer 21

80% recover completely, 15% minimally disabled, 5% severely disabled

Poor prognosticators:

• Need for mechanical ventilation
• Axonal damage
• Older age
• Rapid progression of disease to tetraplegia w/in 1 wk from onset