Neuropathic Pain is chronic pain state caused by damage or disease affecting the nervous system. It may be divided into peripheral neuropathic pain, central neuropathic pain, or mixed (peripheral and central). Peripheral: After a peripheral nerve lesion, aberrant regeneration may occur. Neurons become unusually sensitive and develop spontaneously pathological activity, abnormal excitability, and heightened sensitivity to chemical, thermal and mechanical stimuli. This phenomenon is called "peripheral sensitization". Central: The dorsal horn cells give rise to the spinothalamic tract which constitutes the major ascending nociceptive pathway. With contentious activity in the peripheral nociceptors they develop increased responses to afferent impulses, including normally non harmful tactile stimuli. This phenomenon is called central sensitization. Central sensitization is an important mechanism of persistent neuropathic pain. Regarding PT role in Central and peripheral sensitization, manual therapy can produce central analgesic effects, through activation of descending anti-nociceptive pathways. which with repetition may results in long-term activation of descending anti-nociceptive pathways.

Is a chronic pain condition that most often affects one limb (arm, leg, hand, or foot) usually after an injury such as a fracture or after surgery. The cause is unknown. it has two subtypes: Type I : -previously called reflex sympathetic dystrophy- refers to CRPS without evidence of a specific peripheral nerve injury. Type II: previously called causalgia- refers to when there is specific evidence of a nerve injury. Symptoms: - Prolonged severe pain that may be constant that is continuous burning or throbbing pain. - Changes in skin texture on the affected area; it may appear shiny and thin and tender. - Abnormal sweating pattern in the affected area or surrounding areas. - Sensitivity to touch or cold. - Swelling of the painful area. - Stiffness in the joints. Treatment: Taking vitamin C after a fracture(wrist) and early mobilization may help to prevent CRPS. The outcome of CRPS is highly variable. with younger people, tending to have better outcomes. While older people can have good outcomes, with some experiencing severe pain and disability. - physical therapy (exercises, contrast bath). - Mirror box therapy. - Psychotherapy. - Medications.

This systematic review confirmed the presence of central sensitization in tendinopathy mainly in the upper limb tendons, but results cannot be generalized to the lower limb. In fact, it is often argued that unlike upper limb tendinopathy, individuals with lower limb tendinopathy do not display evidence of central sensitization. http://bjsm.bmj.com/content/early/2018/05/30/bjsports-2017-098863 True or False