[Heschl's gyrus identification using functional MRI: neurosurgical issue].

Area of Science:

• Neuroimaging
• Auditory Neuroscience
• Functional Magnetic Resonance Imaging (fMRI)

Background:

• Localizing Heschl's gyrus using fMRI is challenging due to signal noise and concurrent language area activation.
• Existing auditory paradigms often fail to isolate primary auditory cortex activity.

Purpose of the Study:

• To develop and validate an fMRI paradigm for precise activation of the primary auditory cortex.
• To differentiate primary auditory cortex from adjacent language areas for surgical planning.

Main Methods:

• Ten healthy adults underwent fMRI while performing a visual task and passively listening to an auditory paradigm (tones and rhythmic stimuli).
• Statistical Parametric Mapping (SPM) was used for data analysis.
• Activation was identified by analyzing pixels in functional images.

Main Results:

• A visual decisional task effectively minimized language area activation, allowing for pure primary auditory cortex imaging.
• Strong and selective fMRI activation was consistently observed in Heschl's gyrus across all subjects.
• The paradigm demonstrated high sensitivity in isolating the target auditory region.

Conclusions:

• This fMRI paradigm reliably isolates primary auditory cortex activation, specifically in Heschl's gyrus.
• The technique provides crucial differentiation between resectable auditory cortex and non-resectable language areas.
• This method serves as a valuable preoperative tool for surgical planning in the superior temporal region.