1100 - Autonomic dysreflexia caused by mycotic aneurysm of the abdominal aorta in a C6 tetraplegic patient

Case Diagnosis: Autonomic dysreflexia caused by mycotic aneurysm of the abdominal aorta in a C6 tetraplegic patient

Case Description:

A 69-year-old male with complete C6 tetraplegia (AIS A), tracheostomy, and percutaneous endoscopic gastrostomy presented to clinic with autonomic dysreflexia (AD), manifesting as diaphoresis, tachycardia, and severe hypertension. Repositioning failed to reduce his blood pressure. A bladder scan ruled out urinary retention. Given his recent history of respiratory failure and a known L2 Chance fracture from a fall three months prior, he was transferred to the ED for hypertensive urgency. CT pulmonary angiography, initially obtained to rule out pulmonary embolism, instead revealed pseudoaneurysmal dilation of the abdominal aorta and a diffuse infiltrative process at L1-L2, consistent with a mycotic aneurysm. Notably, blood cultures were negative.

Discussions:

AD is a neurologic emergency in patients with SCI at or above T6. While a search for common noxious stimuli like urinary retention or pressure injuries is imperative, this case demonstrates that refractory AD without a clear trigger can be a red flag for occult, life-threatening pathology. In this case, the etiology was a mycotic aneurysm with fistula formation into the adjacent lumbar vertebrae. This rare diagnosis must be considered in tetraplegic patients with AD of unknown origin, particularly given their susceptibility due to SCI immune deficiency syndrome, and warrants a high index of suspicion and urgent advanced imaging. 

Conclusions:

A review of the literature yielded no prior documented cases of mycotic aneurysm manifesting as AD, underscoring that unexplained dysreflexia necessitates an aggressive workup for pathology. Mycotic aneurysms, though rare, have a dual risk: direct morbidity from rupture and indirect risk from recurrent AD, which itself can cause its own potentially life-threatening issues if left untreated. Due to the advanced nature of the patient’s disease and overall prognosis, the care plan was transitioned to prioritize comfort measures.