First published December 27, 2018 - More info
BACKGROUND. Awake neurosurgery requires patients to converse and respond to visual or verbal prompts to identify and protect brain tissue supporting essential functions such as language, primary sensory modalities, and motor function. These procedures can be poorly tolerated due to patient anxiety, yet acute anxiolytic medications typically cause sedation and impair cortical function.
METHODS. In this study, direct electrical stimulation of the left dorsal anterior cingulum bundle was discovered to reliably evoke positive affect and anxiolysis without sedation in an epilepsy patient undergoing research testing during standard, in-patient intracranial electrode monitoring. These effects were quantified using subjective and objective behavioral measures, and stimulation was found to evoke robust changes in local and distant neural activity.
RESULTS. The index patient ultimately required an awake craniotomy procedure to confirm safe resection margins in the treatment of her epilepsy. During the procedure, cingulum bundle stimulation enhanced positive affect and reduced the patient’s anxiety to the point that intravenous anesthetic/anxiolytic medications were discontinued and cognitive testing was completed. Behavioral responses were subsequently replicated in two patients with anatomically similar electrode placements localized to an approximately 1cm span along the anterior dorsal cingulum bundle above genu of the corpus callosum.
CONCLUSIONS. The current study demonstrates a robust anxiolytic response to cingulum bundle stimulation in three epilepsy patients.
TRIAL REGISTRATION. The current study was not affiliated with any formal clinical trial.
FUNDING. This project was supported by the American Foundation for Suicide Prevention and the National Institutes of Health.