From the Guidelines
Guillain-Barré Syndrome (GBS) affects the peripheral nervous system, with predominant involvement of the somatic nervous system rather than the autonomic nervous system, but when autonomic dysfunction does occur, it typically affects the sympathetic nervous system (SNS) more than the parasympathetic nervous system (PSNS). This is based on the most recent and highest quality evidence available, including a study published in 2021 in the Journal of Clinical Oncology 1. The study highlights the importance of monitoring for autonomic dysfunction in patients with GBS, particularly those with severe cases, as it can lead to significant morbidity and mortality.
Key Points
- Autonomic dysfunction in GBS can manifest as cardiovascular abnormalities, including blood pressure fluctuations, cardiac arrhythmias, and abnormal hemodynamic responses to medications.
- The pathophysiology involves demyelination and axonal damage to sympathetic fibers, disrupting normal sympathetic tone and reflexes.
- Patients with significant autonomic involvement require careful cardiovascular monitoring, especially during the acute phase of illness, as sudden cardiac arrest can occur.
- Treatment focuses on supportive care, with cautious use of medications that might further affect autonomic function, and management of specific symptoms like hypertension or bradycardia as they arise.
Evidence Summary
The evidence suggests that GBS is a complex condition that can affect both the somatic and autonomic nervous systems. While the somatic nervous system is primarily affected, autonomic dysfunction can occur, particularly in severe cases. The sympathetic nervous system is more commonly affected than the parasympathetic nervous system, leading to cardiovascular abnormalities and other complications. Studies have consistently shown that monitoring for autonomic dysfunction and providing supportive care can improve outcomes in patients with GBS 1.
Clinical Implications
In clinical practice, it is essential to monitor patients with GBS closely for signs of autonomic dysfunction, particularly those with severe cases. This includes regular assessment of cardiovascular function, including blood pressure and heart rate, as well as monitoring for other complications such as respiratory failure. Treatment should focus on supportive care, with cautious use of medications that might further affect autonomic function. By prioritizing monitoring and supportive care, clinicians can improve outcomes and reduce morbidity and mortality in patients with GBS.
From the Research
Autonomic Nervous System Involvement in Guillain-Barré Syndrome
The autonomic nervous system, which includes both the Sympathetic Nervous System (SNS) and the Parasympathetic Nervous System (PSNS), can be affected in Guillain-Barré Syndrome (GBS).
- Dysautonomia, a condition characterized by autonomic nervous system dysfunction, has been observed in GBS patients, with symptoms such as ileus, hypertension, hypotension, fever, tachycardia or bradycardia, and urinary retention 2.
- The study found that 38% of GBS patients had at least one manifestation of dysautonomia, with the demyelinating form of GBS being more commonly associated with dysautonomia 2.
- Another study reported a case of GBS presenting with primarily psychiatric and autonomic dysfunction preceding muscle weakness, highlighting the potential for CNS involvement in GBS 3.
Comparison of SNS and PSNS Involvement
While the studies do not provide a direct comparison of the involvement of the SNS and PSNS in GBS, they suggest that both systems can be affected.
- The symptoms of dysautonomia observed in GBS patients, such as hypertension and hypotension, suggest that both the SNS and PSNS can be involved 2.
- However, the studies do not provide sufficient evidence to determine which system is more affected in GBS.
Clinical Implications
The involvement of the autonomic nervous system in GBS can have significant clinical implications.