Corpus callosotomy
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Corpus callosotomy | |
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Specialty | neurology |
Corpus callosotomy is a
After the operation, the brain has much more difficulty sending messages between the hemispheres. Although the corpus callosum is the largest white matter tract connecting the hemispheres, some limited interhemispheric communication is still possible via the anterior commissure and posterior commissure.
"Efficacy and relatively low permanent morbidity in corpus callosotomy for medically intractable epilepsy have been demonstrated by more than six decades of experience. In addition to seizure reduction, behavior and quality of life may improve."[2]
History
The first examples of corpus callosotomy were performed in the 1940s by Dr. 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. Wagenen's work preceded the 1981 Nobel Prize-winning research of Roger W. Sperry by two decades. Sperry studied patients who had undergone corpus callosotomy and detailed their resulting split-brain characteristics.[3]
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. Currently, the surgery is a
Typical procedure
Prior to surgery, the patient's head must be partially or completely shaven. Once under
Indications
Corpus callosotomy is intended to treat patients who have epilepsy and the resultant chronic seizures. The diminished life expectancy associated with epilepsy patients has been documented by population-based studies in Europe. In the United Kingdom and Sweden, the relative mortality rate of epileptic patients (patients whose epilepsy was not under control from medical or other surgical therapies, and who continued to have the disease) increased two- and threefold, respectively. In the vast majority of cases, corpus callosotomy abolishes instance of seizures in the patient.[8]
Contraindications
Although it varies from patient to patient, a progressive
Neuroanatomical background
Corpus callosum anatomy and function
The corpus callosum is a fiber bundle of about 300 million fibers in the human brain that connects the two cerebral hemispheres. The interhemispheric functions of the corpus callosum include the integration of perceptual, cognitive, learned, and volitional information.[9]
Role in epileptic seizures
The role of the corpus callosum in epilepsy is the interhemispheric transmission of epileptiform discharges. These discharges are generally bilaterally synchronous in preoperative patients. In addition to disrupting this synchrony, corpus callosotomy decreases the frequency and amplitude of the epileptiform discharges, suggesting the transhemispheric facilitation of seizure mechanisms.[10]
Drawbacks and criticisms
Side effects
The most prominent non-surgical complications of corpus callosotomy relate to
Another complication is alien hand syndrome, in which the affected person's hand appears to take on a mind of its own.[12]
Cognitive impairments may be seen.[13] (Other symptoms may occur after the operation, but generally go away on their own: Scalp numbness, feeling tired or depressed, headaches, difficulty speaking, remembering things, or finding words.[14])
Alternatives
Epilepsy is also currently treated by a less invasive process called vagus nerve stimulation. 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.[15] However, corpus callosotomy has been proven to offer significantly better chances of seizure freedom compared with vagus nerve stimulation (58.0% versus 21.1% reduction in atonic seizures, respectively).[16] If a focal area in the brain is generating severe seizures, it can sometimes be removed.[citation needed]
See also
References
- ^ S2CID 6007475.
- ^ S2CID 19256444.
- S2CID 6007475.
- PMID 22120324.
- S2CID 34733721.
- ISBN 978-0-306-45134-8.[page needed]
- PMID 26407094.
- S2CID 20595932.
- S2CID 1164423.
- S2CID 10604808.
- S2CID 19538184.
- S2CID 15889976.
The alien hand syndrome is a deeply puzzling phenomenon in which brain-damaged patients experience their limb performing seemingly purposeful acts without their intention. Furthermore, the limb may interfere with the actions of their normal limb.
- PMID 26885171.
- ^ "Corpus Callosotomy - Treatments - For Patients - UR Neurosurgery - University of Rochester Medical Center". www.urmc.rochester.edu.
- S2CID 13346234.
- PMID 26247311.
Further reading
- Maxwell, Robert E. (6 August 2009). "Chapter 162 - Corpus Callosotomy". In Lozano, Andres M.; Gildenberg, Philip L.; Tasker, Ronald R. (eds.). Textbook of Stereotactic and Functional Neurosurgery (2nd ed.). ISBN 978-3-540-69959-0.
- Olivier, André; Boling, Warren W.; Tanriverdi, Taner (2012). "Callosotomy". Techniques in Epilepsy Surgery: The MNI Approach. Cambridge University Press. pp. 201–215. ISBN 978-1-107-00749-9.
- Roberts, David W. (17 August 2009). "Chapter 74 - Corpus Callosotomy". In Shorvon, Simon; Perucca, Emilio; Engel Jr, Jerome (eds.). The Treatment of Epilepsy (3rd ed.). ISBN 978-1-4051-8383-3.
- Sauerwein, Hannelore C.; Lassonde, Maryse; Revol, Olivier; Cyr, Francine; Geoffroy, Guy; Mercier, Claude (15 December 2001). "Chapter 26 - Neuropsychological and Psycho-social Consequences of Corpus Callosotomy". In Jambaqué, Isabelle; Lassonde, Maryse; Dulac, Olivier (eds.). Neuropsychology of Childhood Epilepsy. Advances in Behavioral Biology Series. Vol. 50. ISBN 978-0-306-46522-2.
External links
- Detail on the procedure from epilepsy.com
- Encyclopedia of Surgery: Corpus callosotomy