Introduction: Task selection is one of the pivotal steps for successful localization and activation of speech areas (Broca’s and Wernicke’s) using functional MRI. Multiple tasks are available, which can be used for activation of Broca's area. However, localization of Wernicke's area using fMRI is difficult. Here, we compare the results of three different activation tasks, sentence completion (SC), word generation (WG) and category naming (CAT) for localization of Wernicke's area.
Methods: 11 right handed healthy volunteers (22 to 55y) were included. IRB approval was obtained. Subjects were trained on each task prior to scanning. GE Healthcare provided equipment. Scans were done on a GE 3.0T, 32 channel head coil. Experiments were block design. For SC, subjects were presented with incomplete sentences to complete. On WG and CAT, subjects were asked to generate words that either start with the alphabet shown on the screen or related to the category displayed. During rest, subjects were presented with a gibberish sentence during the first task and a picture of a hand on the second and third tasks. FMRI was acquired using EPI sequences.
Results: Multiple uncorrected Pvalues of cluster probability were used, ranging from 0.05 to 0.001. ROI analysis of Wernicke’s spatial coordinate revealed no activation in CAT and WG across different Pvalues. However, for Sentence Completion task with a cluster probability of an uncorrected Pvalue (<0.001), activation in Wernicke's area was detected with a Tvalue of 4.45. On individual analysis, during SC 9 out of 11 (82%) subjects shows activity in wernicke's spatial coordinates, compared to only 2 (18%) and 3 (27%) subjects with activity in the same coordinates in WG and CAT, respectively.
Conclusions: Sentence completion task is a more effective task in localizing Wernicke's areas compared to Word generation and Category naming tasks.
Patient Care: Sentence completion task is an effective task in localizing Wernicke's areas by fMRI.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of functional MRI localization of Wernicke’s areas using sentence completion task, 2) Discuss, in small groups, the disadvantages of other tasks to localized Wernicke by fMRI 3) Identify an effective treatment option applying fMRI identified Wernicke areas