Guillain-Barré Syndrome

a rare and serious condition of the peripheral nervous system. It occurs when the body's

immune system attacks part of the nervous system.

ETIOLOGY

GBS is common to all races and ages; mild increase in frequency in patients between ages 30-50; GBS is less common in infants or the elderly.

GBS has a yearly incidence of 0.6-1.9 cases/100,000 population.

Prior infection is well established as a precipitating event in the development of GBS. GBS preceded by an acute illness, 1-4 weeks before, in about 75% of cases.

ETIOLOGY

GBS may rarely develop within a day or two, or after 4-6 weeks, of an acute illness.

Most antecedent illnesses associated with GBS affect the upper respiratory or GI tracts.

Cytomegalovirus (CMV) is the most common viral antecedent infection with serologic evidence in up to 15% of cases

ETIOLOGY

Epstein Barr (EBV) infection may precede GBS in about 10% of cases; preceding clinical signs include mononucleosis, hepatitis, or pharyngitis.

GBS may occur with HIV seroconversion.

Camplylobacter jejuni (C. jejuni) is, overall, the most common antecedent infection and has been reported in up to 32% of cases.

GBS may possibly occur after surgery, trauma, and in the post-partum period.

PATHOGENESIS

Guillain-Barré syndrome is an autoimmune disorder that affects the nerves.

In Guillain-Barré syndrome, the immune response damages peripheral nerves, which are the nerves that connect the central nervous system (the brain and spinal cord) to the limbs and organs.

PATHOGENESIS

Specifically, the immune response affects a particular part of peripheral nerves called axons, which are the extensions of nerve cells (neurons) that transmit nerve impulses.

Guillain-Barré syndrome can affect the neurons that control muscle movement (motor neurons);

PATHOGENESIS

The neurons that transmit sensory signals such as pain, temperature, and touch (sensory neurons); or both.

As a result, affected individuals can experience muscle weakness or lose the ability to feel certain sensations.

TYPES

Acute Inflammatory Demyelinating Polyradiculoneuropathy (AIDP)

In AIDP, the immune response damages myelin, which is the covering that protects axons and promotes the efficient transmission of nerve impulses.

TYPES

Acute motor axonal neuropathy (AMAN)

The axons of motor neurons are damaged.

Acute motor-sensory axonal neuropathy (AMSAN).

The axons of motor and sensory neurons are also damaged.

TYPES

Because of sensory nerve damage, affected individuals can lose the ability to sense the position of their limbs and can have abnormal or absent reflexes (areflexia).

TYPES

Miller Fisher Syndrome Involves cranial nerves, which

extend from the brain to various areas of the head and neck. Miller Fisher syndrome is characterized by three features: weakness or paralysis of the muscles that move the eyes (ophthalmoplegia), problems with balance and coordination (ataxia), and areflexia.

CLINICAL MANIFESTATIONS

Muscle weakness or paralysis. The weakness often begins in the legs and spreads to the arms, torso, and face and is commonly accompanied by numbness, tingling, or pain.

Dysphagia and Dyspnea. Occasionally, the nerves that control

involuntary functions of the body such as blood pressure and heart rate are affected, which can lead to fluctuating blood pressure or an abnormal heartbeat (cardiac arrhythmia).

DIFFERENTIAL DIAGNOSIS

History taking Standard blood tests Cerebrospinal fluid examination Electromyography – may be

helpful to establish the diagnosis.

NEUROLOGIC EXAMINATION

Facial weakness (cranial nerve VII) is observed most frequently, followed by symptoms associated with cranial nerves VI, III, XII, V, IX, and X.

Upper extremity, trunk, facial, and oropharyngeal weakness is observed to a variable extent.

Reflexes are absent or reduced early in the disease course.

TREATMENT

Plasma Exchange (PE) or Plasmapheresis

a process in which some of the patient's blood is removed, the liquid part separated, and the blood cells returned to the body, has been used for severe cases.

TREATMENT

Intravenous Immunoglobulin (IVIg)

healthy immunoglobulin is taken from blood donors and given to intravenously (directly into a vein). The healthy antibodies block and destroy the harmful antibodies that are attacking the nerves. IVIg is given usually every day for five days. Each infusion takes about two hours.

MANAGEMENT

Supportive Care: ICU monitoring & basic medical management

Maintaining Respiratory Function: Monitoring for changes in vital capacity and

negative inspiratory force Mechanical ventilation is required if the vital

capacity falls, making spontaneous breathing impossible and tissue oxygenation inadequate.

Suctioning may be needed to maintain a clear airway.

MANAGEMENT

For autonomic dysfunction: Assessment of BP and HR

frequently. Sustained hypertension managed

by ACE inhibitor or beta blocking agent.

Postural hypotension treated with fluid bolus or positioning.

Urinary difficulties may require intermittent catheterization.

MANAGEMENT

For nosocomial infections: Antibiotic therapy should be

reserved.

For Deep Vein Thrombosis: Range-of-motion exercises,

position changes, anticoagulation, the use of anti-embolism stockings or sequential compression boots, and adequate hydration decrease the risk of DVT.

MANAGEMENT

Nutritional Support: Administer IV fluids and

parenteral nutrition as a supplement and monitor for the return of bowel sounds.

Nasogastric tube needed in patients who are intubated or have significant oropharyngeal weakness.

PROGNOSIS

Results of studies on recovery rates differ, but most indicate that 60% to 75% of patients recover completely.

Residual deficits of varying degree occur in 20% to 25% of patients. Residual deficits are most likely in patients with rapid disease progression, those who require mechanical ventilation, and those 60 years of age or older.

Death occurs in 5% of cases, resulting from respiratory failure, autonomic dysfunction, sepsis, or pulmonary emboli.