What are the Causes of Brain Lesions?

Brain lesions, changes to the tissue of the brain, can be associated with a number of different causes, including physical trauma, congenital malformations in the brain, infections, and progressive neurological diseases. Abnormal tissue in the brain is a cause for medical concern and can be identified on imaging studies of the brain such as magnetic resonance imaging. Patients with suspected brain lesions are evaluated by neurologists, physicians who specialize in caring for the brain, spinal cord, and peripheral nervous system. Options for management of a lesion can include medication and surgery.

One cause for lesions on the brain is a congenital problem with the brain, such as an inherited anomaly in the brain or a problem that developed during fetal development. Malformations inside the brain can take a variety of forms, such as Chiari malformations in the cerebellum and arteriovenous malformations in the blood supply to the brain. These lesions may be diagnosed shortly after birth when an infant appears to have neurological deficits, or they may be discovered years later.

Tumors are another cause of brain lesions. Brain tumors arise from tissue throughout the brain and can be associated with exposure to pollutants, random mutations, and other causes. As tumors grow and spread, they can put pressure on healthy brain cells and potentially cause cell death. Hydrocephalus, where fluid builds up inside the skull, can also cause lesions on the brain by killing healthy brain cells with pressure.

People with traumatic head injuries, as well as people who have undergone brain surgery, can have lesions caused by physical trauma to the brain. Penetrating wounds to the head, surgical or otherwise, also have the risk of introducing bacteria and viruses. Infections can cause lesions, including abscesses, where pus and other fluids build up in a pocket inside the brain. Diseases like multiple sclerosis, Alzheimer's disease, and Parkinson's disease also cause brain lesions by damaging the cells in the brain.

Brain lesions can cause a variety of symptoms, depending on the site of the lesion. People can start to experience cognitive deficits like slurred speech, memory loss, difficulty reasoning, and so forth. They can also develop tremors, unstable gaits, and other physical problems caused by poor coordination and signaling between the brain and peripheral nervous system. An evaluation can be conducted to determine the extent of a patient's deficits and diagnostic tools like brain scans will provide more information.

Medications can sometimes treat brain lesions by addressing the cause or halting progress. Surgery to excise a lesion can be another treatment option. In some cases, there may not be any treatment options beyond supportive care to keep the patient comfortable.