Orbitofrontal and insular epilepsy

Abstract

Purpose: Orbitofrontal and insular epilepsy are difficult to recognize because clinical presentations are variable and surgical approaches remain difficult.

Methods: Literature review and review of our own case series including selected cases regarding the clinical manifestation and diagnostic utility of diagnostic tests in orbitofrontal and insular epilepsy.

Results: Orbitofrontal epilepsy presents with either frontal lobe type seizures with hypermotor automatism or temporal lobe type seizures with oroalimentary and manual automatisms depending on the spread pattern. Ictal single photon emission computed tomography (SPECT) and other functional imaging can be helpful, but intracranial electroencephalograms (EEGs) are still required to identify orbitofrontal seizure onset. Insular epilepsy presents with throat constriction and unilateral paresthesias. Preoperative functional imaging methods can be helpful, but exploration of the insula is required to identify unequivocal insular onset. Intracranial EEG in the insula can be performed safely and should be considered in atypical temporal lobe cases.

Conclusions: Intracranial EEG remains the main diagnostic modality to identify orbitofrontal and insular epilepsy. Newer diagnostic modalities such as high-frequency oscillations, EEG, functional magnetic resonance imaging (fMRI), magnet resonance spectroscopy, and magnet source imaging need to be examined further to establish their diagnostic utility.