Diagnosis of consciousness using EEG in patients with severe brain damage.

Research project objectives / research hypothesis The main objective of this project is the development and assessment of diagnostic sensitivity of four brain activity measurement protocols aimed at detecting consciousness in patients with severe brain damage. Such protocols are intended to increase overall validity of differential diagnosis of disorders of consciousness (DOC) by complementing clinical scales based on behavioural assessment. These four study protocols are: auditory and haptic-auditory steady-state responses and neural correlates of single and repetitive movement attempt to command. Another project objective is the development of the Polish version of the JFK Coma Recovery Scale - Revised. The function of this tool is differential diagnosis, prognostic assessment, and treatment planning in patients with disorders of consciousness.

Research project methodology Electroencephalography is the principal measurement technique employed in this project. Being a relatively low-cost solution it enables a non-invasive measurement at the patient’s bedside. The paradigms using steady-state responses are passive (since they do not impose any task on the subject) and their purpose is estimation of the patient’s neural network integrity after it’s been perturbed using periodic sensory stimulation. The paradigms aimed at detection of the of intention to move are called active, because patient is asked to attempt an action requiring a conscious volition. EEG is used here to detect neural correlates of that attempt. During the course of the project a number of regular visits to long-term care centres is planned. Each patient will be tested several times. This will help to establish the validity of the proposed methods, their sensitivity to changes in patient’s condition, and the prognostic value of the tests. The project schedule predicts a number of visits to the DOC patients research centres. Those visits will serve the purpose of presenting and discussing the obtained results with more experienced teams and exchange of research know-how.

Expected impact of the research project on the development of science, civilization and society An accurate diagnosis of DOC patients is exceptionally difficult. The proportion of inaccurate judgments can be as high as 40%. One cannot deem the errors made during diagnostic process responsible for that fact, because the main issue here is the ambiguity of the symptoms manifested by patients themselves. The development of relatively easy-to-use “objective” methods of assessing the patient’s current condition can increase validity of the diagnostic outcomes. The word “objective” means here a method which not based on interpretation of the external behaviours of patients. As to the scientific impact of the project, it will broaden our knowledge about the aspects of impaired brain function in this group of patients. and deepen our understanding of the brain mechanisms of consciousness in general. Development of the Polish version of the JFK Coma Recovery Scale - Revised will provide the medical personnel involved in care and therapy of DOC patients with a new diagnostic method, much better than the currently predominating Glasgow Coma Scale.