Temporal Lobe Epilepsy Health Article

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.

Recovery and rehabilitation

Recovery and rehabilitation are a consideration if epilepsy surgery is performed. If a partial temporal lobectomy has been done, the patient remains in the hospital for several days. Post-operatively, there can be headaches and nausea that are managed with medications and resolved in one to three days. Complications of surgery are rare but include infection (managed with antibiotics) and bleeding (which, if severe, may require a transfusion). Neurological deficits are uncommon; when they are present they are usually mild. This includes a limited visual field deficit, contralateral (opposite to surgical side) weakness or speech difficulty. When neurological complications occur, they usually improve with time and are not disabling.

Clinical trials

Currently there is a multicenter randomized controlled trial (Early Randomized Surgical Epilepsy Trial called ERSET) comparing epilepsy surgery and optimal pharmacotherapy in patients 12 years and older with mesial TLE within two years of determination of pharmacoresistance. The official website is <http://www.erset.org>. Information is also available from the National Institute of Neurological Disorders and Stroke <http://www.ninds.nih. gov> regarding other funded studies under the general heading of epilepsy.

Prognosis

The prognosis for TLE varies considerably depending on the type of TLE. Although medications should be tried initially, mesial TLE and many of the lateral TLEs are often resistant. Timely referral to an epilepsy center that can determine the nature of the seizure disorder and offer other kinds of treatment approaches should be undertaken. Epilepsy surgery for mesial TLE offers up to an 80% chance of sustained seizure freedom and the possibility of discontinuing medications.

Special concerns

Long-standing, poorly controlled epilepsy has a number of psychosocial ramifications. These can include (but are not limited to) memory difficulty, reduced self-es-teem, depression, reduced ability for gainful employment, and greater difficulty with interpersonal relationships. These issues may be underestimated in the setting of treating the seizure disorder. Recognizing the psychosocial well-being of the patient will greatly help in improving quality of life.

BOOKS

Browne, T. R., and G. L. Holmes. Handbook of Epilepsy, 2nd edition. Lippincott Williams & Wilkins, 2000.

Devinski, O. A Guide to Understanding and Living with Epilepsy. F. A. Davis Company, 1994.

Engel, Jr. J., and T. A. Pedley. Epilepsy: A Comprehensive Textbook. 3 volumes. Lippincott-Raven, 1998.

Wyllie, E. The Treatment of Epilepsy: Principles and Practice, 3rd Edition. Lippincott Williams & Wilkins, 2001

PERIODICALS

Kwan, P., and M. J. Brodie. "Early Identification of Refractory Epilepsy." New England Journal of Medicine 342 (2000): 314–319.

Wiebe, S., Blume, W. T., and J. P. Girvin. "A Randomized, Controlled Trial of Surgery for Temporal-lobe Epilepsy." New England Journal of Medicine 345, no. 5 (August 2, 2001): 311–89.