Empirical techniques for determining the reliability, magnitude, and pattern of neuropsychological change after epilepsy surgery.
OBJECTIVE
We assessed test-retest neuropsychological performance in patients with complex partial seizures to derive reliable change indices (RCIs) and regression-based norms for change, indices that may be helpful in assessing cognitive outcome after anterior temporal lobectomy.


METHODS
Forty patients with complex partial seizures (CPS) who did not undergo epilepsy surgery were administered a comprehensive neuropsychological battery on two occasions. Their test-retest data were used to compute both RCIs and regression-based norms for change for each neuropsychological index. RCIs corrected for practice effects provide a confidence interval (CI) indicating the degree of performance change required to exceed the variability attributable to sources of error (e.g., practice, test-retest reliability). Regression-based norms for change also correct for several sources of measurement error and examine observed versus expected test-retest changes on a common metric, thereby facilitating determination of the degree and relative magnitude of change across cognitive domains.


RESULTS
Mean changes in test-retest performance were generally modest, but were evident across several test measures. Our data indicate a considerable degree of individual variability in test-retest performance.


CONCLUSIONS
RCIs and regression-based norms are complementary indexes and can be particularly useful in examining the test-retest performance of individual patients who undergo epilepsy surgery as well as in the more general investigation of cognitive outcome after epilepsy surgery.
Hermann
B P
BP
Department of Neurology, University of Wisconsin Medical Center, Madison 53792, USA.
Seidenberg
M
M
Schoenfeld
J
J
Peterson
J
J
Leveroni
C
C
Wyler
A R
AR
D000328:Adult; D017668:Age of Onset; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis / Q000523:psychology; D016001:Confidence Intervals; D017029:Epilepsy, Complex Partial / Q000175:diagnosis / Q000523:psychology / Q000601:surgery*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011183:Postoperative Complications / Q000175:diagnosis / Q000523:psychology; D011597:Psychomotor Performance; D012044:Regression Analysis; D015203:Reproducibility of Results; D012737:Sex Factors; D013702:Temporal Lobe / Q000601:surgery*; D016896:Treatment Outcome; D014888:Wechsler Scales