Reexamining the effects of epilepsy surgery on IQ in children: Use of regression-based change scores

AbstractPrior studies have found no adverse effects of pediatric epilepsy surgery on IQ. However, empirical techniques such as regression models, designed to account for confounding factors such as practice effects and test–retest reliability and able to provide a standardized method for evaluating outcome, have not been used in studying change after pediatric epilepsy. The goal of this study was to demonstrate the regression technique while empirically measuring the effect of epilepsy surgery on IQ in a group of pediatric patients. Predictors of retest IQ (e.g., baseline IQ, retest interval, demographics, epilepsy severity) were evaluated in a control group with intractable seizures (N = 23) assessed twice with the WISC–III. The resulting equation was used to evaluate IQ changes in a second group of children who underwent epilepsy surgery (N = 22). In controls, baseline IQ was a strong predictor of retest IQ. Number of AEDs was inversely related to retest IQ. Based on the control regression, four children (18%) in the surgical sample obtained significantly higher than expected postsurgical IQ scores and one child (5%) obtained a lower than expected IQ score. This study demonstrates that regression-based techniques yield informative estimates on outcome and may be an improvement over prior methods of measuring change after pediatric epilepsy surgery. (JINS, 2003, 9, 879–886.)

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Pediatric epilepsy surgery: could age be a predictor of outcomes?

Journal of Neurosurgery Pediatrics ◽

10.3171/2015.10.peds14413 ◽

2016 ◽

Vol 18 (2) ◽

pp. 235-241 ◽

Cited By ~ 15

Author(s):

Benoit Jenny ◽

Nicolas Smoll ◽

Yassine El Hassani ◽

Shahan Momjian ◽

Claudio Pollo ◽

...

Keyword(s):

Epilepsy Surgery ◽

Intractable Epilepsy ◽

Pediatric Epilepsy ◽

University Hospitals ◽

Chi Square ◽

Intractable Seizures ◽

Antiepileptic Medication ◽

Pediatric Epilepsy Surgery ◽

Chi Square Test ◽

Free Rate

OBJECTIVE Like adults, many children suffering from intractable seizures benefit from surgical therapy. Although various reports indicate that early intervention may avoid severe developmental consequences often associated with intractable epilepsy, surgery is still considered a last option for many children. In this retrospective study, the authors aimed to determine whether pediatric epilepsy surgery, in particular during the first years of life, relates to measurable benefits. METHODS Data from 78 patients (age range 5 months to 17 years) who underwent epilepsy surgery at the Geneva and Lausanne University Hospitals between 1997 and 2012 were reviewed retrospectively. Patients were dichotomized into 2 groups: infants (≤ 3 years of age, n = 19), and children/adolescents (4–17 years of age, n = 59). Compared with children/adolescents, infants more often had a diagnosis of dysplasia (37% vs 10%, respectively; p < 0.05, chi-square test). RESULTS The overall seizure-free rate was 76.9%, with 89.5% in infants and 72.9% in the children/adolescents group. Infants were 2.76 times as likely to achieve seizure-free status as children/adolescents. Postoperative antiepileptic medication was reduced in 67.9% of patients. Only 11.4% of the patients were taking more than 2 antiepileptic drugs after surgery, compared with 43% before surgery (p < 0.0001). The overall complication rate was 15.1% (6.4% transient hemiparesis), and no major complications or deaths occurred. CONCLUSIONS The data show a high seizure-free rate in children ≤ 3 years of age, despite a higher occurrence of dysplastic, potentially ill-defined lesions. Pediatric patients undergoing epilepsy surgery can expect a significant reduction in their need for medication. Given the excellent results in the infant group, prospective studies are warranted to determine whether age ≤ 3 years is a predictor for excellent surgical outcome.

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