Temporal Lobe Epilepsy
Diagnosis
The diagnosis of TLE can be made by a careful history (of an accurate description of the seizures) coupled with abnormalities on high resolution magnetic resonance imaging (MRI) of the brain and electroencephalogram (EEG). Current MRIs are sensitive, but subtle lesions such as mesial temporal sclerosis can be missed either by routine MRIs or inexperienced radiologists. The routine EEG (usually 30 minutes of testing) can be normal between seizures but may sometimes show occasional characteristic wave patterns in the temporal regions suggesting the location of seizure generation. Long term monitoring with EEG/closed circuit T.V. (LTME) is extremely helpful to determining which temporal lobe is abnormal.
Treatment
The treatment goal of any epilepsy is freedom from seizures with no side-effects of medications. Although this is the goal, it is frequently not attained. There may be a highly variable response to medications. There are over 20 seizure medications available. It is important to understand, however, that if a trial of up to three different well-chosen medications alone or in combination fail to control seizures, then the likelihood that some other medication will work is slim. Therefore, the general concept is that not all medications and combinations need to be tried to know if an epilepsy will be resistant. A timely referral to a comprehensive epilepsy center should be done to explore other treatment options, such as surgery. In mesial TLE, medications frequently fail to adequately control the seizures. Fortunately, this particular epilepsy is most responsive to surgical treatment. Brain surgery should not be viewed as "a last resort" when pharmacoresistant epilepsies are considered. With modern screening methods and neurosurgical technique, complications are rare. The surgery for mesial TLE offers up to an 80% chance of cure. The surgery involves the removal of a portion of the affected temporal lobe. On the other hand, seizures that are generated from other areas of the temporal lobe are more complicated.
