Auditory aura in frontal opercular epilepsy: sounds from afar

Area of Science:

• Neurology
• Epileptology
• Neuroimaging

Background:

• Auditory auras are commonly associated with temporal neocortex epilepsy.
• The precise origin of auditory auras can be challenging to determine non-invasively.

Observation:

• Two cases of epilepsy with auditory auras originating from the frontal operculum are presented.
• Non-invasive evaluations (ictal SPECT, magnetoencephalography) suggested frontal operculum involvement.
• Invasive monitoring (stereoelectroencephalography, subdural electrodes) confirmed ictal onset in the frontal operculum.

Findings:

• Spontaneous and electrically-induced seizures initiated in the frontal operculum in both cases.
• Electrical stimulation of the frontal operculum triggered auditory auras in one patient.
• Surgical resection of the frontal operculum and insula resulted in seizure freedom for one patient.

Implications:

• These findings challenge the traditional view of auditory aura localization.
• The frontal operculum and its connections to the perisylvian and insular networks are critical for auditory aura generation.
• Revisiting non-invasive data, like ictal SPECT, in light of these findings is crucial for accurate epilepsy localization.