When Epilepsy Surgery Fails … There is Often a Second Chance
Authors: Marks William J. 
Published: July 2005

Temporal Lobe Epilepsy: Analysis of Failures and the Role of Reoperation

Salanova V, Markand O, Worth R

Acta Neurol Scand 2005;111:126–133

Purpose

To analyze failures and reoperations in temporal lobe epilepsy to compare these patients with those who are seizure free, and to determine any significant differences between the groups.

Methods

A total of 262 patients with temporal lobe epilepsy, treated surgically between 1984 and 2002, were followed up at 3, 6, and 12 months, and yearly thereafter. Sixty-five percent became seizure free (class I), 19% had rare seizures (class II), and 16% continued to have seizures (classes III and IV). Patients in classes III and IV underwent reevaluation and were compared with seizure-free patients.

Results

Analysis of failures ( n = 41): 12% had febrile seizures; 29%, head trauma; 7%, encephalitis; 52%, abnormal imaging; 34%, bitemporal spiking; and 20%, posterior temporal localization. Postsurgical MRI (available in 30 of 41 patients) showed residual posterior mesial temporal structures (PMTS) in 86.6%, PMTS and posterior temporal lesions in 6.6%, and posterior temporal lesions in another 6.6%. Twenty-one had reoperation, 14 had resection of the PMTS, five of the PMTS and basal posterior temporal cortex, and two of the PMTS, and posterior temporal lesions. No surgical mortality or morbidity was found; 57% became seizure free, and 24% had rare seizures. Seizure-free patients ( n = 170): 45% had febrile seizures; 12%, head trauma; and 70%, abnormal imaging studies.

Conclusions

When compared with seizure-free patients, patients who failed temporal lobe epilepsy surgery were less likely to have a history of febrile seizures and abnormal imaging, and more likely to have a history of head trauma, encephalitis, and posterior temporal localization, suggesting larger epileptogenic zones. After reoperation, 57% became seizure free. Predictors of a good outcome after reoperation were anterior temporal localization and abnormal imaging studies. Resective Reoperation for Failed Epilepsy Surgery: Seizure Outcome in 64 Patients Siegel AM, Cascino GD, Meyer FB, McClelland RL, So EL, Marsh WR, Scheithauer BW, Sharbrough FW Neurology 2004;63:2298–2302

Purpose

To determine the surgical outcome and factors of predictive value in patients undergoing reoperation for intractable partial epilepsy.

Methods

The authors retrospectively studied the operative outcome in 64 consecutive patients who underwent reoperation for intractable partial epilepsy. Demographic data, results of comprehensive preoperative evaluations, and the seizure and neurologic outcome after reoperation were determined. All patients were followed up for a minimum of 1 year subsequent to their last operative procedure.

Results

Fifty-three patients had two surgeries, and 11 patients had three or more operations. The first surgery involved a lesionectomy ( n = 33), “nonlesional” temporal lobe resection ( n = 28), and a “nonlesional” extratemporal resection ( n = 3). The mean duration between the first and second procedure was 5.5 years. Fifty-five patients underwent an intralobar reoperation, whereas nine had a resection of a different lobe. After reoperation, 25 (39%) patients were free of seizure, 6 (9%) patients had rare seizures, 12 (19%) patients had a worthwhile improvement, and 21 (33%) patients failed to respond to surgery. Predictors of seizure-free outcome were age at seizure onset older than 15 years ( p = 0.01), duration of epilepsy 5 years or less at the time of initial surgery ( p = 0.03), and focal interictal discharges in scalp EEG ( p = 0.03). By using a logistic regression model, two significant predictors emerged: duration of epilepsy ≤5 years (odds ratio, 3.18; p = 0.04) and preoperative focal interictal discharge (odds ratio, 4.45; p = 0.02). Complications of reoperation included visual field deficits ( n = 9), wound infection ( n = 2), subdural hematoma ( n = 1), and hemiparesis ( n = 1).

Conclusions

Reoperation may be an appropriate alternative form of treatment for selected patients with intractable partial epilepsy who fail to respond to initial surgery.