Brain Lesions

A brain lesion is usually brain tissue that has an abnormal appearance. Brain lesions can be due to a variety of things. A lesion can show up on an MRI scan. The term lesion, though, can be somewhat vague and can mean several different things. Seeing a lesion on an MRI scan may not be enough to enable a doctor to make a proper diagnosis of the condition. A doctor may need to do a follow up evaluation to determine the cause of the brain lesion. Sometimes specific areas of the brain may be lesioned on purpose for a therapeutic effect in certain disorders. Transcranial magnetic stimulation can induce a temporary brain lesion. There other techniques that are available that can make these lesions more permanently. The cause of a brain lesion showing up on a brain scan can be the result of several different things. They include;

A cerebral infarction describes the loss of brain tissue and this can show up as a lesion on a head scan. When a stroke occurs it can lead to a cerebral infarction. After a stroke, localized areas of the brain can permanently die off. In the future stroke damaged could possibly be repaired using stem cells. Japanese scientists have recently used stem cells to create brain tissue. They have already been used to repair stroke damage in rats in the past. The company Reneuron has just recently gotten the go ahead from the FDA to commence clinical trials using stem cells on human stroke patients.

Alzheimer's disease and certain other types of dementias may also be associated with specific types of brain lesioning. In both of these conditions, brain cells tend to die off as the disease progresses. Currently the treatments for these conditions are fairly limited. Most Alzheimer's drugs available do not halt brain cell death over time. However new drugs that directly inhibit the build up of neuron killing proteins have shown some promise for combating Alzheimer's. So there is hope that they may be approved in the near future.

Cancerous tumors can also show up as lesions on a brain scan. Researchers have been using ultrasound to non-invasively penetrate the brain recently. Ultrasound at specific frequencies can be used to kill cancer cells in the brain.

Temporary lesions can be induced using non-invasive brain stimulation such as TMS. TMS uses magnetic pulses that pass through the skull and generate an electric current in the brain. Low frequency pulses can decrease brain cell activity and this can induce a localized temporary lesion. Researchers do this to test out the circuitry of the human brain to find out how specific regions function.