Rates of success

Most centers are now reporting that at least 70% to 80% of patients undergoing temporal lobectomies have a marked reduction in seizures or seizure freedom. Variations in the statistics on the success of epilepsy surgery are largely due to the patient selection process rather than differences in surgical techniques. Among patients with well-localized, discrete epileptogenic areas of the anterior temporal lobe, seizure activity can be totally arrested in a very high percentage of cases. If surgery is performed on patients with more widespread epileptogenic brain areas, a smaller percentage will become seizure-free.

Frontal lobectomies produce total arrest of seizures in 30% to 40% of patients in most published series. These numbers are less significant statistically than the numbers for temporal lobectomies, however, because relatively few frontal lobectomies are carried out in epilepsy surgery centers. Frontal lobe epilepsy tends to involve more widespread brain regions than other types of epilepsy, so successful surgical resection is much more difficult to achieve.

Recent advances in imaging, neurophysiologic monitoring, intracranial grid mapping, and surgical image guidance have led to improved outcome following surgery for extra-temporal epilepsy. Some epilepsy surgery centers are reporting success rates between 50% and 70% for these challenging cases.

Complications

Potential risks, complications, and benefits, as well as treatment alternatives, must be discussed in detail with the patient and family prior to surgery. In general, the potential benefits must clearly outweigh any risks.

Infection is the most frequent complication of epilepsy surgery, as it is for all operative procedures. The rate of infection is in the 1% to 2% range in most busy epilepsy surgery centers.

Intraoperative or postoperative hemorrhage leading to severe deficits in speech or motor function or even to severe brain injury, coma, or death is extremely rare but possible when any intracranial procedure is carried out.

Transient speech deficits can occur if the removal comes near speech areas or speech pathways. The risk of a permanent speech deficit, even with fine testing, is quite low as long as the guidelines for removal are followed.

Loss of recent memory function for a few months to a year or more after surgical intervention is not infrequent. Memory for verbal material in dominant-side procedures and for nonverbal material for nondominant-side procedures is most likely to be affected. Long-term follow-up studies with precise cognitive testing indicate that the changes in function are fairly minimal in most patients. Many series demonstrate improvement in cognitive functioning after the successful arrest of seizures by surgery, because ongoing seizure discharges often impair memory and speech functions.

The risk of loss of vision in a quadrant or a complete homonymous hemianopsia is extremely low if regular guidelines are followed.

Psychosocial outcome

The uniqueness of the patient's personality and brain function characteristics are not changed by lobectomy. Past problems with depression or other emotional disturbances may recur, however, and may even be magnified in the early postoperative phase.

Some patients whose seizures are successfully arrested have difficulty in adjusting to their new state and their new relationships to their family and society as a whole. Some find this period of adjustment to be so difficult that they require considerable support from their families and from a psychiatrist or psychologist for up to a year or more after surgery.

For about 6 weeks to 6 months after surgery, most patients become easily fatigued and are often disturbed by crowds, noise, or activity around them.

Attempting challenging cognitive tasks, such as those required in a school environment, in the first 6 to 12 months after surgery is usually not advisable: just like other people who have had a brain injury or brain surgery, these patients may have difficulty during this time. Nevertheless, many patients who are employed can return to their previous work within 6 to 12 weeks after surgery as long as allowances are made for their limitations during the recovery process.

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