RESEARCH PAPERS

Preoperative fMRI predicts memory decline following anterior temporal lobe resection

H W R Powell¹, M P Richardson², M R Symms¹, P A Boulby¹, P J Thompson¹, J S Duncan¹, M J Koepp¹

¹ Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, UK and MRI Unit, National Society for Epilepsy, Chalfont St Peter, UK
² Department of Clinical Neuroscience, Institute of Psychiatry, Kings College London, London, UK

Professor J S Duncan, Department of Clinical and Experimental Epilepsy, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK; j.duncan{at}ion.ucl.ac.uk

Background: Anterior temporal lobe resection (ATLR) benefits many patients with refractory temporal lobe epilepsy (TLE) but may be complicated by material specific memory impairments, typically of verbal memory following left ATLR, and non-verbal memory following right ATLR. Preoperative memory functional MRI (fMRI) may help in the prediction of these deficits.

Objective: To assess the value of preoperative fMRI in the prediction of material specific memory deficits following both left- and right-sided ATLR.

Methods: We report 15 patients with unilateral TLE undergoing ATLR; eight underwent dominant hemisphere ATLR and seven non-dominant ATLR. Patients performed an fMRI memory paradigm which examined the encoding of words, pictures and faces.

Results: Individual patients with relatively greater ipsilateral compared with contralateral medial temporal lobe activation had greater memory decline following ATLR. This was the case for both verbal memory decline following dominant ATLR and for non-verbal memory decline following non-dominant ATLR. For verbal memory decline, activation within the dominant hippocampus was predictive of postoperative memory change whereas activation in the non-dominant hippocampus was not.

Conclusion: These findings suggest that preoperative memory fMRI may be a useful non-invasive predictor of postoperative memory change following ATLR and provide support for the functional adequacy theory of hippocampal function. They also suggest that fMRI may provide additional information, over that provided by neuropsychology, for use in the prediction of postoperative memory decline.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Cheung, M-C, Chan, A S, Lam, J M K, Chan, Y-L (2009). Pre- and postoperative fMRI and clinical memory performance in temporal lobe epilepsy. J. Neurol. Neurosurg. Psychiatry 80: 1099-1106 [Abstract] [Full Text]