Atypical Autonomic-Predominant Guillain-Barré Syndrome With Pandysautonomia Mimicking Parkinsonism and Recurrent Syncope: A Case Report.

Guillain-Barré syndrome with pandysautonomia can mimic neurodegenerative and cardiogenic conditions, particularly in elderly patients presenting with autonomic symptoms and parkinsonian features. Timely neurologic evaluation and ganglioside antibody testing-especially anti-GM2-are essential for accurate diagnosis and the initiation of immunotherapy, which may result in significant clinical improvement even in atypical, chronic presentations.