Developing a comprehensive presurgical functional MRI protocol for patients with intractable temporal lobe epilepsy:...

Area of Science:

• Neuroimaging
• Epilepsy Research
• Cognitive Neuroscience

Background:

• The Wada test (intracarotid amytal test) is standard for assessing language and memory lateralization before epilepsy surgery.
• Limitations of the Wada test include invasiveness and potential complications.
• There is a need for non-invasive neuroimaging techniques to evaluate these functions.

Purpose of the Study:

• To develop and validate a comprehensive functional MRI (fMRI) protocol.
• To assess the protocol's efficacy in localizing language and memory functions.
• To evaluate the protocol as a potential alternative to the Wada test for epilepsy patients.

Main Methods:

• A rapid (under 1 hour) fMRI protocol was designed for a 1.5 tesla imager.
• Five cognitive paradigms were employed: scene encoding, picture naming, reading, word generation, and semantic decision.
• Nine healthy right-handed subjects participated in the study.

Main Results:

• The fMRI protocol generated distinct activation maps for memory and language functions.
• Memory-related activation was observed in the mesial temporal lobes.
• Language lateralization was reliably achieved using word generation and reading tasks, identifying key areas like the anterior temporal pole and middle temporal gyrus.

Conclusions:

• The developed fMRI protocol successfully maps language and memory functions in healthy subjects.
• The protocol demonstrates potential as a non-invasive alternative to the Wada test for pre-surgical evaluation in epilepsy.
• Further comparative studies with the Wada test in epilepsy patients are warranted.