Compression neuropathies: Clinical presentation and diagnostics

Entrapment neuropathies: Challenging common beliefs with novel evidence Schmid, A. B., Hailey, L., & Tampin, B. Level of Evidence: 5 Follow recommendation: 👍 Type of study: Symptoms prevalence, Aetiologic, Diagnostic Topic: Compression neuropaties - Presentation and diagnostics This is a narrative review on clinical presentation, aetiology, and diagnostic tests for peripheral neuropathies (e.g. carpal tunnel syndrome - CTS). The clinical presentation of compression neuropathies rarely follows peripheral nerve patterns. For example, CTS often presents with symptoms in the whole hand and forearm, which extend beyond the innervation territory of the median nerve. This widespread pain presentation appears to be mediated by an immune-inflammatory response, which is initiated by nerve compression. This inflammatory response can lower neurons' depolarisation threshold, contributing to widespread symptoms. Diagnostic tests for compression neuropathies involve both nerve conduction studies and clinical tests. Nerve conduction studies assess large nerve fibre function. Nerve conduction studies confirm CTS diagnosis in 75% of patients. It is suggested that the remaining 25% of patients with CTS present with a mild compression of the median nerve, which does not affect large fibre function. These mild forms of CTS may be identified by assessing small nerve fibres through clinical tests such as the pinprick tests (pain sensation elicited by a sharp object) and patients' ability to percive warmth/cold through warm/cold coins. If patients are unable to perceive pain during a pinprick test or they are unable to differentiate between warm/cold sensation, the diagnosis of CTS is more likely. Neurodynamic tests are not useful for diagnostic purposes, but they can detect an increased sensitivity of the neural structures. Clinical Take Home Message: Carpal tunnel syndrome may present with uncommon symptom distrubutions. Nerve conduction studies are useful in identifying a severe median nerve compression. Clinical tests including pinprick (utilising single use devices such as Neurotips) and warmth/cold detection may be used to confirm a CTS diagnosis. Neurodynamic tests can only identify an heightened sensitivity of neural structures and should not be used to make a diagnosis of CTS. URL: