LAUSR

To the Editor: We read with great interest a recently published article entitled “Ultrasound of the Radial Nerve: A Pictorial Review” by Beciollini et al in your esteemed journal. The manuscript is excellent and well describes the complex sonographic anatomy of the radial nerve, its branches and related pathologies. The illustrations are covering all the potential sites of compression of the radial nerve, its deep motor and sensory divisions. The authors have also described a rare entity and involvement of the radial nerve by neuralgic amyotrophy. The different types of abnormalities in neuralgic amyotrophy are also well illustrated. This pictorial essay proved to be an eye-opener as we recently come across a case of radial neuropathy which remained a diagnostic dilemma until now. A young male patient presented with pain along the elbow and forearm, predominantly during extension. This was followed by paresis during the 3 months in the form of wrist and index finger drop. The distribution of motor weakness and nerve conduction study suggested the radial neuropathy. Sensory function was intact. High-resolution ultrasonography (USG) of the radial nerve and its course showed thickening of the deep motor branch of the nerve along the radial tunnel (Figure 1). Significant thickening of the posterior interosseous nerve (PIN) was also evident along the supinator canal. Fatty atrophy of the brachioradialis, brachialis, supinator, and extensor muscles were also noted suggesting chronic neuropathy (Figure 2). The etiology was unclear as there was no evidence of nerve compression/entrapment on any potential site. Now after reading this pictorial essay, we are suspecting the diagnosis of neuralgic amyotrophy of the radial nerve and PIN. Hence, I would like the authors to explain the diagnostic possibilities in the case and if any other marker needs to be evaluated for confirmation. In our clinical experience, there were instances where the clinical and nerve conduction studies strongly suggested radial neuropathy but the ultrasound appearance of the radial nerve and its course