AAN Guideline Assesses fMRI for Presurgical Evaluation of Patients With Epilepsy
Like the IAP, cognitive fMRI “is a complex diagnostic procedure that requires both advanced technical expertise in imaging and expert interaction with patients to elicit adequate levels of task performance, select a set of activation tasks appropriate to the patient’s ability and the clinical aims of the study, instruct the patient on the tasks, administer the tasks during scanning, and evaluate and provide corrective feedback on task performance during the scanning session,” said the authors.
Global amnesia may result from bilateral medial temporal lobe damage, and some neurologists depend on the IAP to evaluate a patient’s risk for this outcome. “Global amnesia is rare after unilateral temporal lobe surgery, however, and occurs mainly when there is preexisting contralateral medial temporal lobe dysfunction,” said the authors. “One possible approach, therefore, is to reserve use of the IAP memory test for those patients at greatest risk for global amnesia, that is, patients undergoing unilateral anterior temporal lobe resection who have structural or functional evidence of damage to the contralateral medial temporal lobe.”
“Larger studies need to be conducted to increase the quality of available evidence,” Dr. Szaflarski concluded.
—Erik Greb
Suggested Reading
Szaflarski JP, Gloss D, Binder JR, et al. Practice guideline summary: Use of fMRI in the presurgical evaluation of patients with epilepsy—Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology. Neurology. 2017 Jan 11 [Epub ahead of print].
