MRI Findings of Bilateral Anterior Tarsal Tunnel Syndrome - A Case Report

Anterior tarsal tunnel syndrome, an infrequent entrapment neuropathy involving the deep peroneal nerve beneath the inferior extensor retinaculum in the anterior ankle, is often overlooked on medical images, leading to delayed diagnosis and treatment. We present the case of a 52-year-old male, an avid runner, who exhibited a sensation of burning and tingling in the dorsal region of both feet. Electrophysiologic studies suggested bilateral deep peroneal neuropathy. Subsequent magnetic resonance imaging revealed bilateral focal regions of signal alteration, consistent with scarring, encasing the deep peroneal nerves at the anterior tarsal tunnel. These regions were indented by the deep laminae of the inferior extensor retinacula, suggesting compression. The constellation of findings was consistent with anterior tarsal tunnel syndrome. This is a unique case of bilateral deep peroneal nerve entrapment exacerbated by repetitive microtrauma, culminating in anterior tarsal tunnel syndrome. Notably, this case represents the first instance in literature where MRI played a pivotal role in diagnosis.