Corpus callosotomy

[3] Although the corpus callosum is the largest white matter tract connecting the hemispheres, some limited interhemispheric communication is still possible via the anterior and posterior commissures.

The first instances of corpus callosotomy were performed in the 1940s by William P. van Wagenen, who co-founded and served as president of the American Association of Neurological Surgeons.

Attempting to treat epilepsy, van Wagenen studied and published the results of his surgeries, including the split-brain outcomes for patients.

Most of the surgeries involved a partial division of the corpus callosum and resulted in improvements of seizure control in all patients.

[2] Improvements to surgical techniques, along with refinements of the indications, have allowed van Wagenen's procedure to endure; corpus callosotomy is still commonly performed throughout the world.

In a study of children with a severe intellectual disability, total callosotomy was performed with highly favorable results and insignificant morbidity.

In addition to disrupting this synchrony, corpus callosotomy decreases the frequency and amplitude of the epileptiform discharges, suggesting the transhemispheric facilitation of seizure mechanisms.

[16] One characteristic symptom is the "crossed-avoiding reaction", which is observed when one hemisphere does not respond to visual or sensory (e.g., touch, pressure, or pain) stimuli presented to the opposite side.

[20] Other symptoms may occur after the operation but generally go away on their own, such as scalp numbness, feeling tired or depressed, headaches, and difficulty speaking, remembering things, or finding words.

This method utilizes an electrode implanted around the left vagus nerve within the carotid sheath in order to send electrical impulses to the nucleus of the solitary tract.