Visual half-field testing for defining cerebral hemisphere speech laterality.
The purpose of this study was to investigate to what extent the noninvasive visual half-field (VHF) test can reliably determine cerebral speech dominance for the individual patient with partial epilepsy considered for surgical treatment. The present VHF test consisted of a list of 36 words presented correctly and mirrored in the lateral visual fields to 13 right-handed and 14 left-handed control subjects and to 14 right-handed and 2 left-handed patients with partial epilepsy. In the controls, it was found that all right-handed and 10 out of 14 left-handed control subjects showed a right VHF (i.e., left hemisphere) advantage. Three of the left-handed control subjects showed the opposite pattern, and one showed no visual field advantage. All of the right-handed patients showed a right VHF advantage, except one who showed no VHF advantage. The two left-handed patients had both a left VHF advantage. Intracarotid amytal speech testing documented left hemisphere speech dominance in all right-handed patients. Of the two left-handed patients, one had right-sided, the other bilateral speech representation. The results suggest that the present VHF test reliably predicts cerebral hemisphere speech in patients with epilepsy.
Säisä
J
J
Department of Psychology, University of Umeå, Sweden.
Silfvenius
H
H
Christianson
S A
SA
D000293:Adolescent; D000328:Adult; D000654:Amobarbital; D004292:Dominance, Cerebral / Q000502:physiology*; D004828:Epilepsies, Partial / Q000503:physiopathology* / Q000601:surgery; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D013060:Speech / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*
D000654:Amobarbital