James H. Lau, MD
Resident, PGY-3
University of North Carolina at Chapel Hill
Chapel Hill, North Carolina, United States
Kathryne Bartolo, MD
Assistant Professor
University of North Carolina at Chapel Hill
Chapel Hill, North Carolina, United States
An 87-year-old female with history of childhood left ankle fracture managed non-operatively presented with left foot drop that began 15 years ago without inciting event. She had completed 1 month of physical therapy with minimal improvement. Examination was significant for 1/5 ankle dorsiflexion, 0/5 hallux flexion and extension, 0/5 ankle inversion and eversion, and absent left Achilles reflex. Electrodiagnostic study was consistent with left lumbosacral plexopathy with active denervation in left medial gastrocnemius. MRI lumbosacral plexus was unremarkable. MRI left thigh with/without contrast identified a T2 hyperintensity along sciatic nerve in the proximal thigh without evidence of impingement.
Diagnostic ultrasound examination of the left sciatic nerve identified a persistent sciatic artery with an AVM adjacent to the sciatic nerve in the gluteal region. MRA of the left lower extremity confirmed findings.
Patient was evaluated by Vascular & Interventional Radiology who elected to forego AVM embolization as her weakness was tolerable.
Discussions:
To our knowledge, this is the only case of sciatic neuropathy secondary to compression by a gluteal AVM and concurrent persistent sciatic artery.
Conclusions:
Gluteal AVM and a persistent sciatic artery are potential causes of sciatic neuropathy. While rare, it should be considered in a patient with foot drop when central neurologic and other neuromuscular etiologies have been ruled out. Ultrasound can serve as an affordable and low-risk diagnostic tool for the identification of this uncommon vascular anomaly.
