LAUSR

To the Editor: Osei and colleagues recently published a very interesting paper entitled “Cubital Tunnel Syndrome: Incidence and Demographics in a National Administrative Database”.1 We would like to sincerely praise the authors for this brilliant publication about ulnar neuropathy at elbow; cubital tunnel syndrome is a common disease and it represents the second most frequent nerve entrapment.2 Osei and colleagues investigated the incidence of this neuropathy in United States, using a very large database. The authors started from the consideration that knowing the epidemiological impact of this disease in the general population should be desirable for a better management. They found an incidence of about 30 persons per 100 000 per year and an increasing incidence and major frequency of surgically treated cases in older populations.1 The paper is very important for different reasons. First, the authors underlined the significance of an extensive knowledge of a very common disease. In fact, a well-known syndrome may show meaningful features that only large studies and big data collection can reveal. Furthermore, they explored epidemiological aspects of cubital tunnel. This issue is significant because it provides very useful information for the physicians dealing with this neuropathy. In particular, the importance of the paper is due to the analysis of the general population of a whole country. This could stimulate other groups to consider similar studies in order to obtain other country-specific data. Finally, Osei and colleagues presented the findings about the age-related growing incidence, useful information for prognosis. The authors presented the limitations of their study considering the possible bias of misclassification. They wrote that neurophysiological examination could reduce these mistakes, even if its use was not possible because of the study design.1 We agree with authors about the importance of neurophysiology for ulnar neuropathy assessment, but we would like to add the diagnostic importance of imaging tool in this syndrome. In particular, ultrasound (US) is very effective for neuropathy management. We would like to present a case of ulnar nerve dislocation, in which US allowed definition of the diagnosis, in order to show the potential powerful association between clinical evaluation, neurophysiology, and imaging tool. A 41-year-old woman came to our lab for clinical symptoms of left ulnar nerve suffering at elbow (paresthesia at the last 2 fingers during elbow flexion). Clinical examination revealed mild hypoesthesia at the left ring and little fingers and no muscle strength deficit. Electrophysiological examination confirmed the suffering, showing a mild slowing of motor nerve conduction velocity at elbow. US evaluation found enlargement of the left ulnar nerve at elbow, with a cross sectional area of 12 mm2 and a dislocation during the dynamic assessment, ie maximal flexion of the forearm. At the end of this movement, ulnar nerve subluxation was visible (Figure). The subject involved in the study gave informed consent. Our case shows the relevance of US for the assessment of ulnar neuropathy at elbow. The tool is able to see the nerve and allows a dynamic evaluation, providing information about the nerve and the surrounding anatomical structures, essential for eventual surgical palnning.3,4 Obviously, clinical examination is fundamental for diagnosis of peripheral nervous system diseases. The association with specific and efficient instruments, able to provide objective data about patient condition, should be considered in supporting diagnosis, prognosis, therapeutic decision, and rehabilitation programs for neuropathies.