Fascial entrapment neuropathy.

Entrapment neuropathies are debilitating clinical conditions, creating significant morbidity in the upper and lower extremities in terms of pain, sensory abnormalities, and motor weakness, becoming a challenge to diagnose and treat. Because entrapments can have multiple origins, a misinterpretation of anatomy during examination can lead to incorrect diagnosis and treatment. This review addresses understanding of the anatomy of fascia that can play an important role in this syndrome. There is a specific microenvironment around the nerve composed of connective tissues that include deep fascia, intermuscular septa, epineurium, and perineurium. The microenvironmental modifications can be translated into change in mobility with consequence decreasing of the independency of the nerve from the surrounding structures lading to entrapments and "internal stretch lesion." The entrapments reported in this article reinforce the importance of fascia tissue in generating common symptoms that pose more difficult diagnostic challenges and may often be confused with more common clinical conditions. Clin. Anat. 32:883-890, 2019.