Carpal Tunnel Syndrome and Anatomical Variations: A Literature Review

Carpal Tunnel Syndrome (CTS), the most common compressive neuropathy of the upper limbs, results from compression of the median nerve, manifesting with pain and paresthesia. Its etiology is multifactorial, with a higher prevalence in women and the elderly. Intrinsic anatomical variations, such as a bifid median nerve (BNM), a persistent median artery (PMA), and anomalous muscles, can predispose to or aggravate CTS. BNM refers to a division of the median nerve, often associated with the PMA, an embryonic vessel whose persistence demonstrates microevolutionary growth in the population. The PMA is considered a compressive risk factor, although its protective role in nerve perfusion is debated. Anomalous muscles, such as the hypertrophied transversus carpi, also contribute to compression. The coexistence of multiple variations is common. Classic symptoms of CTS may present with atypical manifestations in the presence of anomalies. Diagnosis is clinical, complemented by examinations. Electroneuromyography (ENMG) is the gold standard. Ultrasound (USG) and Magnetic Resonance Imaging (MRI) are crucial for identifying anatomical variations, optimizing preoperative planning. Treatment ranges from conservative to surgical. Surgical decompression, preferably via open surgery in cases with anomalies, allows direct visualization, protects structures, and minimizes iatrogenic injuries. Preoperative identification of variations is therefore vital for surgical safety and efficacy. In conclusion, recognizing anatomical variations is essential in the management of CTS. Accurate diagnosis via imaging allows for personalized treatment planning, optimizing outcomes and patient safety.