1. GROOVED PEGBOARD FINGER TAPPING
The Utility of Motor Tasks and Intelligence Scores in Lateralizing
Seizure Focus in Children with Epilepsy
Jenna K. Schwartz, M.A.1, Sonya S. Kaur, M.A.2,& Jeffrey B. Titus, Ph.D.1,2
1Dell Children’s Comprehensive Epilepsy Program, Austin, Texas
2Department of Psychology, The University of Texas at Austin
Mean VCI and PRI Performance by Handedness and Seizure Focus
Rationale
n = 7
n = 39
Identifying lateralized cerebral dysfunction is a goal of neuropsychology when children are considered for epilepsy surgery. Motor laterality and VIQ/PIQ (or VCI/PRI) discrepancies are among the comparisons used for this purpose, but little information is known about the frequency of lateralized findings in these scores.
The current study was conducted to investigate the frequency and degree of motor and verbal/performance discrepancies in children with partial seizures.
GROOVED PEGBOARD
Methods
n = 50
n = 15
Percentage of Patients with VCI/PRI Discrepancies At or Beyond the .05 Level.
Our sample consisted of 129 children with partial epilepsy who were referred for testing at a tertiary care epilepsy center. The children ranged in age from 5-15 years (M = 10.68; SD = 3), and they were predominantly male (54.7%). All children had a seizure focus that was lateralized to only one cerebral hemisphere, as determined by epileptologists.
Each child was administered a comprehensive neuropsychological battery consisting of measures assessing intellectual ability, academic achievement, fine motor speed and dexterity, graphomotor production, language functioning, memory, and executive functioning. Results of the testing were shared with the comprehensive epilepsy team which included integration of the data with video-EEG monitoring, MRI, SPECT, MEG, and PET findings. Seizure laterality was determined off of the patient’s most recent EEG findings, as interpreted by board certified epileptologists.
Right-sided Seizure Focus
(expected PRI < VCI)
Left-sided
Seizure Focus
(expected VCI < PRI)
Right-handed
20%
23%
Left-handed 0%
40%
Base Rate Expectation
18.7%
22.3%
n = 27
n = 4
Conclusions
Finger tapping identified seizure focus in 45% of children. Grooved pegboard lateralized 44% of children. Motor tasks were particularly effective in right-handed patients with right-sided seizures (67-69%). Lateralization was mixed in left-handed children, and it was particularly poor in right-handed children with a left seizure focus and left-handed children with a right seizure focus. VIQ/PIQ discrepancies revealed only modest variation from expected base-rates. However, 40% of left-handed children with left-sided seizures demonstrated a significant difference.
Our study suggests variable utility in using motor tasks and VIQ/PIQ discrepancies to lateralize seizures in children. Motor tasks are only reliably sensitive in one subgroup. VIQ/PIQ discrepancy failed to demonstrate sensitivity across all seizure groups and only appeared effective in left-handed children with left-sided seizure. These results emphasize the importance of using multiple sources of data across many domains when considering lateralized dysfunction.
References
FINGER TAPPING
Blackburn, L.B., Lee, G.P., Westerveld, M., Hempel, A., Park, Y.D., & Loring, D.W. (2007). The Verbal IQ/Performance IQ discrepancy as a sign of seizure focus laterality in pediatric patients with epilepsy. Epilepsy & Behavior, 10, 84–88.
Stewart, C.C., Swanson, S.J., Sabsevitz, D.S., Rozman, M.E., Janecek, J.K., & Binder, J.R. (2014). Predictors of language lateralization in temporal lobe epilepsy, Neuropsychologia, 60, 93–102.
n = 38
n = 13