200 Section - Atypical Presentation of Guillain-Barré Syndrome Following a Motor Vehicle Accident

Case Diagnosis: Acute Inflammatory Demyelinating Polyneuropathy (AIDP) subtype of Guillain-Barré Syndrome (GBS)

Case Description:

A 55-year-old female presented with inability to bear weight due to bilateral lower extremity weakness. Initially asymptomatic, her symptoms of diminished sensation rapidly progressed throughout all lower-extremity distributions, extending to the perineal region a few hours after a motor vehicle accident. The patient denied any recent history of infections. Initial exam showed preserved strength in all extremities, right and left ankle reflexes were absent. CT scans of the spine were unremarkable except for mild anterolisthesis at L5–S1. Laboratory evaluation was notable for mild leukocytosis. Lumbar puncture demonstrated elevated CSF protein at 154.6 mg/dL and negative comprehensive CSF pathogen testing. Given her acute neurologic sensory and reflex decline following trauma and CSF findings, she was diagnosed with Guillain-Barré Syndrome. She improved with Intravenous Immunoglobulin and was discharged for acute rehabilitation.

Discussions: Trauma-related GBS remains rare, with approximately 136 cases reported in the literature to date, and only a small subset following road-traffic accidents. GBS is an acute autoimmune neuropathy in which an inappropriate immune response targets peripheral nerves, producing rapidly progressive weakness, sensory loss, and sometimes autonomic dysfunction. Although many cases follow infection, trauma is an uncommon trigger, and the mechanisms linking physical injury to immune activation remain unclear. This rarity contributes to diagnostic difficulty, especially when symptoms appear immediately after trauma and resemble spinal or nerve-root injury.

Conclusions: This case highlights that physiological stress can also serve as an uncommon trigger for immune-mediated neuropathy. Although GBS most commonly follows an infectious trigger in up to two-thirds of cases, this patient developed symptoms shortly after a minor motor vehicle accident. Neurology involvement and timely initiation of immunotherapy remain essential and can significantly improve outcomes in patients with trauma-associated GBS. Clinically, this case underscores the importance of considering atypical causes of GBS.