The condition can persist for days, weeks, months, and, in rare cases, even years. However, if the condition persists for more than 12 months, the prognosis is not good. Coma can be caused by several factors, among the most common are: oxygen deprivation, bleeding, or swelling of the brain. Most coma patients have been involved in a traffic collision and have acquired a traumatic injury to the brain or have, for various reasons, suffered a subarachnoidal hemorrhage. The condition can progress very different from patient to patient, and some can regain certain abilities and can be rehabilitated, whereas others may never improve. In general, the tendency is that the longer the coma persist the less chance of an effective rehabilitation.
A specific case has generated interest within the world of neurosurgical research. After 15 years in a coma, it was possible to reestablish a certain level of consciousness in a 35 years old male whom had been involved in a traumatic accident. The team of scientists behind this success has, in consultation with family and experts, experimented with a kind of pacemaker connected to nerves in the patient’s chest.
The vagus nerve performs an important function in consciousness and awareness and forms the connection between the brain and the body. By stimulating this nerve in the patient’s chest with electrical impulses, it was possible to show an increase in brain activity. But not only brain activity was increased - movement of the eyes was registered, and the patient responded to voices and other forms of stimuli. Even after so many years, it was possible for the scientists to reestablish a certain level of consciousness. Additionally, further examination of brain activity through EEG revealed that the electrical impulses associated with movement, perception, and consciousness had increased. Scans of the brain also confirmed an increased metabolism in parts of the cerebral cortex.
Researcher Angela Sirigu from the institute for cognitive sciences in Lyon, claims: “The brain is plastic and reparations are still possible, even after so many years. By stimulating the vagus nerve, it is possible to increase the consciousness of coma patients, even when there previously was no hope.” Future research will now have to focus on and prove on the therapeutic potential of stimulating the vagus nerve and how it can be applied in practice. A pacemaker proved successful with the heart so why not with the nervous system?
References:
- http://www.wissenschaft.de/leben-umwelt/medizin/-/journal_content/56/12054/20015138/Durch-Nervenstimulation-aus-dem-Wachkoma/
- Restoring consciousness with vagus nerve stimulation. Corazzol, Martina et al. Current Biology, Volume 27, Issue 18, R994 - R996
