To what extent can an EEG help us to predict whether - and how - a patient will awaken from a coma following cardiac arrest? This question was addressed by doctoral degree candidate Marleen Tjepkema-Cloostermans. Her conclusion: coma patients with the best prognosis are those whose EEG shows rapid recovery of brain rhythms after resuscitation, with no interruptions in brain activity. They have the greatest chance of recovery with the least amount of damage. Tjepkema-Cloostermans is affiliated with the MIRA Research Institute of the University of Twente and will obtain her doctoral degree on 10 January 2014.
A large proportion of patients who are resuscitated slip into a coma due to the temporary lack of oxygen to the brain. About half of these patients awaken from their coma and are left with little or no neurological damage as a result of the heart failure. Roughly the other half of the patients die or are left with severe brain damage and have to be cared for in a nursing home. Marleen Tjepkema-Cloostermans examined whether you could use an EEG to predict the patient's prognosis just a few days after the heart failure.
Brain activity
A neurologist uses an EEG to measure a patient's brain activity. EEGs are normally used to provide a snapshot assessment and no attention is paid to trends in brain activity. For a long time it was commonly thought that medication made an EEG unreliable. Research by Tjepkema-Cloostermans shows that an EEG does in fact remain reliable. For her research, 148 patients who had slipped into a coma following resuscitation were placed immediately on continuous EEG monitoring. All these patients were admitted to the Intensive Care department for treatment with mild therapeutic hypothermia. This involves bringing the patients' body temperature down to about 33°C for a period of 24 hours. The doctoral degree candidate subsequently looked for characteristics and trends in the EEGs that could predict whether - and how - a patient would awaken from the coma.
Prognosis
It seems that the first 24 hours following resuscitation are crucial. Tjepkema-Cloostermans: "The first day often provides a good first impression of any recovery that can be expected. Coma patients whose EEG shows a rapid recovery of brain rhythms following resuscitation, without any interruptions in brain activity, have the best prognosis. The prognosis of patients who show no brain activity after 24 hours is very poor. Because: the sooner brain activity recovers, the better."
Marleen Tjepkema-Cloostermans expects hospitals to start making more use of EEGs in the future. Tjepkema-Cloostermans: "My research shows that EEGs are useful for making a more rapid prognosis for patients who slip into a coma after resuscitation. Follow-up research will definitely take place. What's more, I expect hospitals to make greater use of EEGs for these patients. This is not, however, standard practice at the moment."
Collaboration
Marleen Tjepkema-Cloostermans carried out her research in collaboration with the departments of Neurology, Clinical Neurophysiology and Intensive Care Medicine at the Medical Spectrum Twente in Enschede and the Rijnstate hospital in Arnhem. Her research is part of the VIP Brains Networks project, which is subsidized by the Ministry of Economic Affairs and the provinces of Gelderland and Overijssel. Tjepkema-Cloostermans will obtain her doctoral degree on 10 January at 14:30 hours at the University of Twente. Her thesis supervisor is Prof. Dr. Ir. M.J.A.M. van Putten, with assistant thesis supervisor Dr J. Hofmeijer.
