EEG-measurements enable better prediction of the outcome of a coma that was caused by a lack of oxygen to the brain. This became clear from research of the University of Twente (MIRA) in cooperation with Rijnstate hospital and Medisch Spectrum Twente. A new method helps to make reliable and correct estimates in about 50% of patients, instead of only 10% of patients with the methods currently used. This involves continuous EEG-measurements focussing on the speed with which the brain's activity recovers. It seems that recovery over time is a better indicator of the severity of brain damage than single brief measurements, which are currently done. The research has been published in the scientific journal Neurology.
Half of the patients with a post-anoxic coma (a coma resulting from lack of oxygen to the brain) never regain consciousness. It is exceptionally difficult to reliably predict which patients are and which are not capable of recovering. Currently, prediction is based on clinical measurements of the depth of the coma in combination with a so-called SSEP measurement. This provides a correct estimate for only ten percent of patients. This is why doctor, and also family-members, need an instrument that is better at determining which patients do and which do not have a chance of recovery.
First 24 hours
Performing a continuous EEG measurement and looking at improvement of brain activity allows a correct estimate in half of the patients. This is shown by research of the University of Twente in cooperation with Rijnstate hospital and Medisch Spectrum Twente.
The published research, which involves data from approximately 300 patients, was carried out during the period from 2011 to 2014. This is the largest dataset ever used for research of EEG in postanoxic coma. According to the first author, dr. Jeannette Hofmeijer (assistant professor at the University of Twente and neurologist at Rijnstate hospital), who set up this research together with prof. dr. ir. Michel van Putten (chairholder Clinical Neurophysiology at the UT and neurologist/clinical neurophysiologist at the MST), EEG based outcome prediction showed less reliable results in previous studies. In the current study, prediction improved importantly by looking at the EEG differently. Instead of using a single EEG measurement, EEG measurements were now made continuously. A single measurement provides insufficient reliable information about the severity of the brain damage and the chance of recovery. Otherwise, by looking at changes in brain activity over time, much more information can be obtained from the EEG.
Improvement of brain activity measured in the first 24 hours is crucial: if there is sufficient improvement within twelve hours, a good recovery can be predicted with a high level of probability, while the prognosis is invariably poor if there is insufficient improvement within 24 hours. Being able to determine the chance of recovery at an early stage provides doctors and families with better information about whether continuation of intensive care treatment makes sense.
The research was initiated and set up by dr. Jeannette Hofmeijer and prof. dr. ir. Michel van Putten and carried out in cooperation with Tim Beernink (medical doctor at Rijnstate), dr. Frank Bosch (intensivist Rijnstate), dr. Albertus Beishuizen (intensivist MST) and dr. Marleen Tjepkema-Cloostermans (technical medicine UT and MST). The research was partly funded by the Dutch Ministry of Economic Affairs, Agriculture and Innovation, province Overijssel and Gelderland (ViP Brain Networks project). Marleen Tjepkema-Cloostermans obtained het PhD in the subject at the University of Twente in 2014.
This improvement in diagnostics is a step forward, but means doctors and family-members are faced with new important medical-ethical questions. Such as: when are the prospects of a coma-patient so poor that stopping treatment is justified? In a new study, doctors and philosophers at the UT's MIRA research institute will start searching for answers to these and other ethical questions. That study will start in the middle of this year and is being funded by the Netherlands Organization for Scientific Research (NWO), the Netherlands Brain Foundation, Clinical Science Systems and Twente Medical Systems International.
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