Assessment of hearing in coma patients employing auditory brainstem response, electroencephalography, and eye-gaze-tracking

The results of the study conducted by Tagliaferri et al. in 12 European countries indicate that the ratio of registered brain injury cases in Europe amounts to 150-300 per 100 000 people, with the European mean value of 235 cases per 100 000 people. The project presented in the paper assumes development of a combined metric of patients’ state remaining in coma by intelligent fusion of GCS (subjective Glasgow Coma Scale or its derivatives) with objective data acquired using ABR (Auditory Brainstem Response), EEG (electroencephalography), and EGT (Eye-Gaze-Tracking). Variety of coma patients from cooperating medical care centers were examined. Senses examination involved the assessment of their function by a medical specialist, with special attention paid to hearing tests results obtained with an ABR measuring device. The assessment included speech-based cognitive functions such as comprehension, phonematic hearing and auditory gnosia. Achieved results are discussed in the paper showing that most patients remaining in coma after a severe brain injury have preserved the ability to receive sound stimuli. [The project was partially funded by the Polish National Science Centre on the basis of the decision No. DEC-2014/15/B/ST7/04724.]