Entrapment syndromes are a group of peripheral nerves disorders characterized by neurological signs or vascular symptoms, due to chronic injury to the nerve as it travels from one body segment to the next. The two leading causes of this pathology are work postures and sports activities, the latter more and more common also in the elderly population. Nerve entrapment is generally caused by localized mechanical pressure from inelastic structures such as an osseoligamentous tunnel or by estrinsic compressions due to neoplasms or anatomic variations.Nerve damage is classified as neurapraxia and symptoms don’t often correlate with nerve damage or histological features. Repetitive injury to a nerve may initially result in microvascular (ischemic) changes in perineural venous system (vasa nervorum) leading to endoneurial edema formation, increase in intraneural pressures and further interference of endoneurial microcirculation with subsequent ipoxia. Injury to the outside layers of the nerve (myelin sheath) leads to perineural fibrosis and, in more advanced stages, focal segmental demyelination related to sclerosis at the area of compression. The diagnosis is made with a thorough clinical examination, allowing to identify the nerve involved in this painful condition and the area of compression and to define the severity of the disease. EMG and, rarely, MRI or echography complete the diagnostic pathway.Operative treatment is reserved for those patients in whom conservative treatment has been unsuccessful. Timing for surgery is dependent on knowing the different anatomical entrapment sites and their specific clinical presentations. Surgical treatment in the early stages of the disease is preferable, before chronic ischemic lesions lead to permanent sensory and motor impairment.
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