Peripheral nerve injury of the upper extremity commonly occurs in patients who participate in recreational (e.g., sports) and occupational activities. Nerve injury should be considered when a patient experiences pain, weakness, or paresthesias in the absence of a known bone, soft tissue, or vascular injury.
Brain injury occurs when the tissues of the brain suffer an acute injury that results in temporary, chronic, or permanent damage and/or dysfunction. The brain is a very sensitive organ subject to injury from a variety of insults. Some of the major causes of brain injury include trauma, lack of oxygen (hypoxic/anoxic injury), lack of blood flow (ischemia), infection, and metabolic disorders.
For other uses, see hypoxia (disambiguation) . Cerebral hypoxia is a form of hypoxia (reduced supply of oxygen) specifically involving the brain; when the brain is completely deprived of oxygen it is called cerebral anoxia.he brain requires approximately 3.3 ml of oxygenated blood per 100 g of brain tissue per minute. Initially the body responds to lowered blood oxygen by redirecting blood to the brain and increasing cerebral blood flow.