Mesial Temporal Sclerosis

Mesial temporal sclerosis (MTS) is also known as hippocampal sclerosis.  This condition is closely related to temporal lobe epilepsy, which simply means that the start of the seizure can be identified within the temporal lobe of the brain.  Mesial temporal sclerosis is due to the loss of neurons and results in the scarring of the hippocampus due to certain brain injuries.  These brain injuries include but are not limited to infection, traumatic injury, tumors, and lack of oxygen to the brain.  Common symptoms include strange sensations, changes in behavior or emotions, muscle spasms, and convulsions.  MTS occurs in 65% of epilepsy patients in autopsy studies. MTS treatment usually includes anti-epileptic medications or temporal lobectomy.

Mesial temporal sclerosis is best viewed using MRI.  The best imaging planes to detect MTS are the coronal plane and the axial plane.  The coronal plane is able to detect volume reduction and T2 signal change while the axial plane is able to detect the posterior extent of hippocampal abnormalities.  Likewise gradient echo techniques are used rather than spin echo due to the smaller slice thickness.  Because gradient echo allows for smaller slice thickness it allows for better imaging of gray and white matter.  On a typical MRI study showing MTS you may find the following abnormalities; reduced hippocampal volume, increased T2 signal, loss of gray and white matter interface in the anterior temporal lobe, atrophy of the ipsilateral fornix and mammillary body.

Above is a video showing MRI images of MTS along with a short clip of a left mesial temporal sclerosis with calcified lesion removal.