Brain Lesions

A brain lesion is an area of damage, injury, or abnormal change to a part of the brain. Brain lesions may be caused by head injury, disease, surgery, or congenital disorders, and they are classified by the cause, extent, and locus of injury. Lesions cause many behavioral symptoms. Symptom severity generally corresponds to the region and extent of damaged brain. Thus, behavior is often a reliable indicator of the type and extent of a lesion. Observations of patients suffering brain lesions were first recorded in detail in the 18th century, and lesion studies continue to shape modern neuroscience and to give insight into the functions of brain regions. Recovery, defined as any return of lost behavioral or cognitive function, depends on the age, sex, genetics, and lifestyle of patients, and recovery may be predicted by the cause of injury. Most recovery occurs within the first 6 to 9 months after injury and likely involves a combination of compensatory behaviors and physiological changes in the brain. Children often recover some function after brain lesions better than adults, though both children and adults experience residual deficits. Brain lesion survival rates are improved by better diagnostic tools and treatments. Therapeutic interventions and treatments for brain lesions include surgery, pharmaceuticals, transplants, and temperature regulation, each with varying degrees of success. Research in treating brain lesions is progressing, but in principle a cure will only be complete when brain lesions are replaced with healthy tissue.