1. Guillain-Barre´ Syndrome

2. Introduction
the most common cause of acute or subacute generalized paralysis
acute-onset, monophasic, immune-mediated polyneuropathy that often follows an antecedent infection
Usually preceded by 1-3 week history of mild respiratory or gastrointestinal symptoms
Campylobacter jejuni – most frequent identifiable antecedent infection
Viral exanthems, other viral illness (CMV, EBV, HIV)
Bacterial infections

3. Antecedent Events Respiratory Infection Gastrointestinal Infection
Campylobacter jejuni
Immunization
Viral Exanthems
Viral illnesses (EBV, CMV, HIV)
Bacterial infections (other than Campylobacter)
Exposure to thrombolytics
Lymphoma (Hodgkin’s)
Trauma
Surgery

4. Epidemiology 0.4 – 1.7% per year Age range: 8 months - 81 years old
Highest: 50 – 74 years old

5. Pathogenesis
autoimmune disease resulting from aberrant immune responses against various components of peripheral nerve fibers
involving both humoral and cell-mediated factors
circumscribed areas containing lymphocytes, macrophages, and localized demyelination are present, scattered throughout the PNS

6. Pathogenesis
Involves roots, plexuses, proximal nerve trunks, some cranial nerves, and autonomic fibers
Often with a predilection, soon after onset, for roots and distal peripheral nerve fibers
Specifically targets the myelin sheath
Macrophages
Penetrate the basal lamina surrounding the axon
Displace the Schwann cell from the myelin sheath
Then phagocytoses the myelin lamellae

7. Clinical Manifestations
Cardinal Features:
Paresthesia
Weakness
Diminished DTRs

8. Clinical Manifestations
Paresthesias and slight numbness in the toes and fingers – earliest
Weakness, symmetrical (several days to weeks)
Proximal  distal
Lower extremities before the upper extremities
Total motor paralysis with respiratory failure (5% of patients)
Ocular motor nerve paralysis

9. Clinical Manifestation
Pain and aching discomfort in the muscles (hips, thighs and back)
Burning sensation on fingers and toes
Sensory loss
Deep sensibility (touch-pressure-vibration) > superficial (pain-temperature)
Loss of DTRs
Disturbances of autonomic function
Sinus tachycardia, facial flushing, fluctuating hypertension and hypotension, episodic profuse diaphoresis

11. Clinical Manifestations
Begins abruptly with distal symmetrical onset of paresthesia.
Sensory disturbances are accompanied by or quickly followed by progressive limb weakness.
Rapid progression
50% of patients – nadir by 2 weeks
90% of patients – by weeks

12. Ancillary Procedures CSF Analysis Nerve Conduction Studies Normal
Elevated protein with normal cell count ~ 50%
Nerve Conduction Studies
Support the clinical impression that the acute motor paralysis is cause by peripheral neuropathy
Conduction block
Differential slowing
Focal slowing

13. Pathophysiology
Acute Inflammatory Demyelinating Polyradiculoneuropathy
Most common form of GBS
characterized pathologically by demyelination, lymphocytic infiltration, and macrophage-mediated clearance of myelin.
2/3 of cases occur weeks after an infection such as C. jejuni, CMV, Mycoplasma pneumonia, or influenza virus
Focal areas of demyelination
Conduction slowing or conduction block
Depending on the severity of the process
Some minor associated axon loss

14. Pathophysiology Acute axonal forms
Present as axon loss polyradiculoneuropathies
Affects motor, or motor and sensory fibers, depending upon the particular subgroup
Roots more affected than peripheral nerves
Motor pattern - wallerian degeneration prominent in ventral roots alone
Motor-sensory pattern - prominent wallerian degeneration in both ventral and dorsal roots

15. Miller Fisher Syndrome
shares many pathophysiological events with AIDP and acute motor axonal neuropathy.
Characterized by the triad of:
Ophthalmoplegia
Ataxia
Areflexia
CSF protein is usually is elevated, but the NCS findings are more suggestive of axon loss than SD

16. Outcome Usually associated with spontaneous remission
15% complete recovery
65% minor deficits not interfering with activities of daily life
5-10% permanent disabling weakness
3-8% mortality

17. Management Supportive care Specific therapy ICU monitoring
Ventilatory support
DVT precautions
Pain management
Nutritional support
Specific therapy

18. Management Immunotherapy Plasma exchange Immunoglobulins
Demonstrated to be beneficial if started within 1 week of illness
Efficacy reduced if started after 3 weeks
Immunoglobulins
Sandoglobulin trial: as efficacious as plasma exchange with few adverse effects
Mechanism:
neutralization of proinflammatory cytokines
down regulation of pathogenic antibodies
modulation of Fc receptor-mediated phagocytosis
inhibition of complement deposition
promotion of remyelination
Corticosteroids