Guillain-Barré Syndrome

 

Introduction

History

Clinical manifestations

Classification:

Diagnosis

Treatment

Prognosis

Summary

Author

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Introduction:

Guillain-Barré Syndrome (GBS) is a rare neurological disorder characterized by an aberrant immune response targeting the peripheral nerve roots (radicles). This pathological process can extend to involve the spinal cord, resulting in radiculomyelitis. In the majority of cases, the inflammatory response is not confined to the nerve radicles but also affects the greater segment, including the proximal portion of peripheral nerves, radicles, and the spinal cord, a condition known as polyradiculomyelitis.

The etiology of Guillain-Barré Syndrome (GBS) remains unclear, although it is frequently preceded by an infectious illness, such as a respiratory tract infection or gastroenteritis. GBS is classified as an acute neurological disorder characterized by a sudden and rapid onset of symptoms. The progression from initial symptoms to peak disability typically occurs within a few days to weeks, distinguishing it from chronic neurological conditions.

The acute phase of GBS often involves severe and potentially life-threatening manifestations, including profound muscle weakness or paralysis that can compromise respiratory function. This necessitates immediate medical intervention.

History:

Guillain-Barré Syndrome (GBS) has a rich history dating back to the early 20th century. Understanding the historical context of GBS provides insight into how medical knowledge and treatment of this condition have evolved.

• Early Descriptions: Late 19th Century: Some of the earliest descriptions of symptoms resembling GBS can be traced back to 1859, when Jean-Baptiste Octave Landry, a French physician, described a condition called "ascending paralysis." Landry's descriptions were pivotal in understanding the progressive nature of the syndrome.
• Identification: 1916: French neurologists Georges Guillain, Jean Alexandre Barré, and André Strohl more clearly defined the syndrome during World War I. They described two soldiers with acute, progressive muscle weakness, loss of tendon reflexes, and abnormal elevation of protein levels in the cerebrospinal fluid without an increase in cell count. This triad of symptoms became the hallmark of GBS. 
• Nomenclature and terminology: The condition was named "Guillain-Barré Syndrome" to honor the contributions of Guillain and Barré. André Strohl's name was not included, although his contributions were significant. 
• Mid-20th Century: Advancements in Diagnosis: Throughout the mid-20th century, advancements in diagnostic techniques, such as electromyography (EMG) and nerve conduction studies (NCS), helped to understand the electrophysiological characteristics of GBS better.
• Recognition of Variants: Researchers began recognizing different forms of the syndrome, such as the Miller-Fisher variant, which primarily affects the cranial nerves and is characterized by ophthalmoplegia, ataxia, and areflexia. Immunological Understanding:
• 1970s and 1980s: Research into the immunological basis of GBS gained momentum. Studies revealed that GBS is an autoimmune disorder in which the body's immune system attacks the peripheral nerves. This understanding led to the development of more targeted therapies.
• Association with Infections: It was established that GBS often follows infections such as Campylobacter jejuni, cytomegalovirus, Epstein-Barr virus, and Zika virus. The role of molecular mimicry, where the immune system mistakes nerve components for pathogens, became a focus of study.
• Modern Treatment Advances: 1980s and Beyond: Treatments such as plasma exchange (plasmapheresis) and intravenous immunoglobulin (IVIG) were developed and found to reduce the severity and duration of GBS symptoms effectively. These treatments have become standard care for managing the syndrome.
• Ongoing Research: Current research continues to explore the underlying mechanisms of GBS, identify potential triggers, and develop new treatments to improve patient outcomes.

Clinical manifestations:

Initial Symptoms: Weakness and tingling in the extremities are often the first symptoms. These sensations can quickly spread, eventually leading to paralysis.

Progression: Symptoms typically start in the feet and legs and may progress to the upper body and arms. In severe cases, the muscles used for breathing can be affected, requiring mechanical ventilation.

Peak Severity: Symptoms usually worsen over days to weeks, peaking within four weeks.

Blood pressure fluctuations and irregular heart rhythms (arrhythmias) are common complications in Guillain-Barré Syndrome (GBS). These issues arise due to the involvement of the autonomic nervous system, which controls involuntary bodily functions such as heart rate and blood pressure.

Autonomic Dysfunction in Guillain-Barré Syndrome

Autonomic Nervous System Involvement: The autonomic nervous system (ANS) controls vital functions, including heart rate, blood pressure, digestion, and respiratory rate. In GBS, the immune system's attack on the peripheral nerves can affect the autonomic nerves, leading to dysfunction in these critical areas.

Blood Pressure Fluctuations:

• Hypertension: Elevated blood pressure can occur due to autonomic dysfunction. This may be intermittent and can vary significantly.
• Hypotension: Low blood pressure can also occur significantly when changing positions (orthostatic hypotension), leading to dizziness or fainting.
• Labile Blood Pressure: Rapid and unpredictable changes in blood pressure, known as labile blood pressure, are common and challenging to manage.

Irregular Heart Rhythms (Arrhythmias):

• Bradycardia: Abnormally slow heart rate can occur due to autonomic dysfunction.
• Tachycardia: Abnormally fast heart rate is another potential issue.
• Other Arrhythmias: Irregularities in heart rhythm, including atrial fibrillation or more complex arrhythmias, can develop and may require specific treatments or interventions.

Urinary Symptoms in Guillain-Barré Syndrome:

• Urinary Retention:

Definition: Difficulty in emptying the bladder entirely or at all.

Cause: Autonomic dysfunction can impair the nerves that control bladder muscles, leading to retention.

• Incontinence:

Definition: Loss of bladder control, leading to involuntary leakage of urine.

Cause: Disruption in the neural pathways that regulate bladder function can cause incontinence.

• Frequency and Urgency:

Frequency: Needing to urinate more often than usual.

Urgency: A sudden, strong need to urinate immediately.

Cause: Autonomic dysfunction can cause the bladder to become overactive.

Cranial nerves involvement:

Cranial nerve involvement occurs in approximately 45-75% of GBS cases and can lead to symptoms, as GBS commonly affects different cranial nerves.

• Facial Nerve (CN VII): The facial nerve is the most commonly affected cranial nerve in GBS, leading to facial weakness or paralysis, often bilaterally. This can cause difficulties in facial expressions, drooping, and an inability to close the eyes thoroughly.
• Oculomotor (CN III), Trochlear (CN IV), and Abducens (CN VI): In some cases, GBS affects eye movement, resulting in ophthalmoplegia (eye muscle weakness), double vision (diplopia), or drooping of the eyelids (ptosis).
• Glossopharyngeal (CN IX) and Vagus Nerve (CN X): These nerves control functions like swallowing, gag reflex, and voice. Their involvement can lead to dysphagia (difficulty swallowing), dysphonia (hoarse voice), or aspiration, which may require medical management.
• Trigeminal Nerve (CN V): Involvement of this nerve is less common but can cause sensory deficits, pain, or weakness in the jaw muscles, affecting chewing.
• Hypoglossal Nerve (CN XII): This nerve can be affected in rare cases, leading to tongue weakness and difficulties in speech and swallowing.

Clasification: 

• Acute Inflammatory Demyelinating Polyradiculoneuropathy (AIDP):

The most common form in the U.S. It primarily affects the myelin sheath, the insulating layer surrounding nerves. 

• Acute Motor Axonal Neuropathy (AMAN) and Acute Motor-Sensory Axonal Neuropathy (AMSAN) are more common in China, Japan, and Mexico. These types affect the axons, the part of the nerve cell that transmits signals.
• Acute Motor-Sensory Axonal Neuropathy (AMSAN)

Description: Similar to AMAN, it also involves sensory nerves.

Pathophysiology: The immune response targets both motor and sensory nerve axons. Characterized by paralysis starting in the eyes, MFS is less common and primarily affects the cranial nerves.

Symptoms: Severe weakness, sensory loss, and more prolonged recovery compared to AIDP and AMAN.

• Miller Fisher Syndrome (MFS):

Description: A rare variant that accounts for about 5% of GBS cases.

Pathophysiology: The immune response explicitly targets nerves in the brainstem and cranial nerves.

Symptoms: Ophthalmoplegia (weakness of the eye muscles), ataxia (lack of voluntary coordination of muscle movements), and areflexia.

• Acute Panautonomic Neuropathy

Description: Scarce and affects the autonomic nervous system.

Pathophysiology: The immune system attacks the nerves that control involuntary body functions.

Symptoms: Severe dysfunction of the autonomic nervous system, including heart rate, blood pressure, and digestion regulation.

• Bickerstaff Brainstem Encephalitis (BBE)

Description: A rare and severe variant closely related to MFS.

Pathophysiology: The immune system attacks the brainstem, causing widespread inflammation.

Symptoms: Similar to MFS with additional signs of brainstem involvement such as consciousness disturbance and hyperreflexia.

• Pharyngeal-Cervical-Brachial (PCB) Variant

Description: Rare and primarily affects the upper limbs and facial muscles.

Pathophysiology: The immune system targets the pharynx, neck, and shoulder nerves.

Symptoms: Weakness in the facial muscles, neck, and arms without significant lower limb involvement.

Diagnosis:

• Clinical Examination: A thorough medical history and physical examination.
• Electromyography (EMG) and Nerve Conduction Studies (NCS): These tests measure the electrical activity in muscles and the speed of nerve signals, helping to confirm the diagnosis.
• Lumbar Puncture: Analyzing cerebrospinal fluid (CSF) can show elevated protein levels with an average white blood cell count, a typical finding in GBS.

Treatment:

• Plasma Exchange (Plasmapheresis): This process removes antibodies from the blood that may attack the nerves.
• Intravenous Immunoglobulin (IVIG): High doses of immunoglobulin can block the damaging antibodies.
• Supportive Care: Management of symptoms and complications, including respiratory support if necessary, physical therapy, and pain management.

Prognosis:

Most people with GBS recover fully or experience only minor, residual weakness or abnormal sensations. However, recovery can take weeks to years, and some may have lingering effects. Early and aggressive treatment can improve outcomes, but some severe cases may result in long-term disability.

Summary:

Guillain-Barré Syndrome is a severe but rare condition that affects the peripheral nervous system, leading to muscle weakness and paralysis. Early diagnosis and treatment are crucial to improve the chances of a good recovery.

By AmirHossein Mahdavian MD

Pediatric neurologist