Activations in temporal areas using visual and auditory naming stimuli: A language fMRI study in temporal lobe epilepsy.
Verbal fluency functional MRI (fMRI) is used for predicting language deficits after anterior temporal lobe resection (ATLR) for temporal lobe epilepsy (TLE), but primarily engages frontal lobe areas. In this observational study we investigated fMRI paradigms using visual and auditory stimuli, which predominately involve language areas resected during ATLR.



Twenty-three controls and 33 patients (20 left (LTLE), 13 right (RTLE)) were assessed using three fMRI paradigms: verbal fluency, auditory naming with a contrast of auditory reversed speech; picture naming with a contrast of scrambled pictures and blurred faces.



Group analysis showed bilateral temporal activations for auditory naming and picture naming. Correcting for auditory and visual input (by subtracting activations resulting from auditory reversed speech and blurred pictures/scrambled faces respectively) resulted in left-lateralised activations for patients and controls, which was more pronounced for LTLE compared to RTLE patients. Individual subject activations at a threshold of T>2.5, extent >10 voxels, showed that verbal fluency activated predominantly the left inferior frontal gyrus (IFG) in 90% of LTLE, 92% of RTLE, and 65% of controls, compared to right IFG activations in only 15% of LTLE and RTLE and 26% of controls. Middle temporal (MTG) or superior temporal gyrus (STG) activations were seen on the left in 30% of LTLE, 23% of RTLE, and 52% of controls, and on the right in 15% of LTLE, 15% of RTLE, and 35% of controls. Auditory naming activated temporal areas more frequently than did verbal fluency (LTLE: 93%/73%; RTLE: 92%/58%; controls: 82%/70% (left/right)). Controlling for auditory input resulted in predominantly left-sided temporal activations. Picture naming resulted in temporal lobe activations less frequently than did auditory naming (LTLE 65%/55%; RTLE 53%/46%; controls 52%/35% (left/right)). Controlling for visual input had left-lateralising effects.



Auditory and picture naming activated temporal lobe structures, which are resected during ATLR, more frequently than did verbal fluency. Controlling for auditory and visual input resulted in more left-lateralised activations. We hypothesise that these paradigms may be more predictive of postoperative language decline than verbal fluency fMRI.
Epilepsy Society MRI Unit, Epilepsy Society, Chalfont St. Peter, SL9 0LR, United Kingdom; Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom.
Gloria G
GG
Gonzálvez
Epilepsy Society MRI Unit, Epilepsy Society, Chalfont St. Peter, SL9 0LR, United Kingdom; Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom. Electronic address: k.trimmel@ucl.ac.uk.
Karin
K
Trimmel
Epilepsy Society MRI Unit, Epilepsy Society, Chalfont St. Peter, SL9 0LR, United Kingdom; Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom.
Anja
A
Haag
Epilepsy Society MRI Unit, Epilepsy Society, Chalfont St. Peter, SL9 0LR, United Kingdom; Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom.
Louis A
LA
van Graan
Epilepsy Society MRI Unit, Epilepsy Society, Chalfont St. Peter, SL9 0LR, United Kingdom; Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom.
Matthias J
MJ
Koepp
Epilepsy Society MRI Unit, Epilepsy Society, Chalfont St. Peter, SL9 0LR, United Kingdom; Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom.
Pamela J
PJ
Thompson
Epilepsy Society MRI Unit, Epilepsy Society, Chalfont St. Peter, SL9 0LR, United Kingdom; Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom.
John S
JS
Duncan
D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D000069279:Drug Resistant Epilepsy / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000523:psychology / Q000601:surgery; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000523:psychology / Q000601:surgery; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D009483:Neuropsychological Tests; D013060:Speech / Q000502:physiology*; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
Anterior temporal lobe; Auditory and visual naming tasks; Functional MRI; Language; Temporal lobe epilepsy; Verbal fluency; Word finding difficulties