Mesial Temporal Sclerosis

Mesial temporal sclerosis is the scarring and loss of neurons in the deepest portion of the temporal lobe. At Columbia Neurosurgery, our physicians are experts in surgically treating mesial temporal sclerosis with temporal lobectomy.


Mesial temporal sclerosis usually results in partial (focal) epilepsy, in which seizures are confined to one area of the brain. The condition can cause a variety of symptoms, such as strange sensations, changes in behavior or emotions, muscle spasms, or convulsions. A focal seizure may spread to become a generalized seizure, which involves the entire brain and may cause a sudden loss of awareness or consciousness.


The changes associated with mesial temporal sclerosis are usually identifiable on a magnetic resonance imaging (MRI) scan. This scan uses magnets, radio waves, and a computer to form pictures of the body’s structures.

Risk Factors

Brain damage from traumatic injury, infection, a brain tumor, stroke, or uncontrolled seizures is thought to cause the scar tissue to form, particularly in the hippocampus. The region begins to atrophy; neurons die, and more scar tissue forms. This damage is thought to be a significant cause of temporal lobe epilepsy. In fact, 70 percent of temporal lobe epilepsy patients have some degree of mesial temporal sclerosis. It also appears that additional seizures can aggravate existing mesial temporal sclerosis.


The surgical treatment for mesial temporal sclerosis is called temporal lobectomy.

In this procedure, neurosurgeons remove the part of the brain identified as the seizures’ point of origin. Patients with mesial temporal sclerosis on only one side of the brain usually have a better outcome than patients with bilateral mesial temporal sclerosis. The best outcomes are achieved with complete removal of the sclerotic structures.

This is the single most common surgery for patients with epilepsy that cannot be controlled with medication. It has a high rate of eliminating seizures and is associated with a low incidence of significant new neurological impairments.