Clinical relevance of memory performance during Wada is stimulus type dependent
- 1Laboratory for Neuropsychology, Ghent University, Ghent, Belgium
- 2Reference Center for Refractory Epilepsy and Department of Neurology, Ghent University Hospital, Ghent, Belgium
- Correspondence to: Guy Vingerhoets Laboratory for Neuropsychology, Ghent University Hospital, De Pintelaan 185, B-9000 Ghent, Belgium; guy.vingerhoets{at}ugent.be
- Received 9 March 2005
- Accepted 5 June 2005
- Revised 18 May 2005
Abstract
Objectives: This study aimed to investigate whether different types of memory stimulus provide different information during the Wada or intracarotid amytal procedure (IAP) in patients with refractory medial temporal lobe epilepsy (MTLE).
Methods: Eighty nine surgical candidates with documented MTLE and selected for left hemispheric language dominance underwent memory assessment with verbal and dually encodable stimuli during a presurgical IAP.
Results: The overall IAP memory performance with the left hemisphere is significantly better than with the right hemisphere regardless of lesion side. This can be explained by the left hemispheric advantage of encoding all stimuli, whereas the right hemisphere has only limited resources to encode verbal stimuli. More importantly, it appeared that dually encodable items remain more readily recognised following injection ipsilateral to the lesion, whereas verbal items are always better recognised following right hemisphere injection regardless of lesion side.
Conclusions: Verbal IAP stimuli show left hemispheric sensitivity in left language dominant MTLE patients. The dually encodable items of the IAP appear lesion sensitive.
Footnotes
-
This work was supported by a Junior Researcher Grant “Arphant” to Kristl Vonck and a Senior Clinical Investigator Grant from the Fund for Scientific Research Flanders and a Clinical Epilepsy Grant from Ghent University Hospital to Paul Boon
-
Competing interests: none declared
