Kiti Muller , Kati Pettersson, Satu Pakarinen, Miikka Korja, Nicolas, Mika Niemela, Jukka Putaala and Martinez-Majander
Nokia Bell Labs Research, Finland
Finnish Institute of Occupational Health, Finland
Helsinki University Hospital, Finland
University of Helsinki, Helsinki, Finland
Scientific Tracks Abstracts: J Neurol Neurophysiol
Patients recovering from surgery frequently experience symptoms of fatigue. Objective measures of fatigue could be used to follow recovery progress, optimize daily activities to patient├ó┬?┬?s resources and evaluate working ability. Increased eye closure time per minute (ECT/min) has been used as an indicator of decreased alertness. We used ECT/min to study fatigue of patients undergoing elective neurosurgical treatment for unruptured intracranial aneurysm. We recorded electro-oculography (EOG) from eight patients (40 yrs., SD 12, 3 male) before (9 am) and after (10:30 am) performing demanding computer tasks simulating knowledge work. During the 6.5 min EOG measurements patients watched a muted video film. The ECT/min values were individually baseline corrected to the mean of the first measurement. Measurements were done 1-22 days before and 1530 days after surgery. All patients were full-time employed with no history of stroke, mental disturbances, and intracranial procedures. In both, pre- and postoperative measurements the ECT/min values were higher after the cognitively demanding tasks (preop: W=774, p=0.008; postop: W=684, p=0.0008), suggesting decreased alertness and/or increased fatigue after tasks. Interestingly no difference was found between pre and postoperative measurements (W=1136, ns.), indicating that fatigue was not significantly greater after surgery. The ECT/min is a promising objective measure to evaluate and follow changes in fatigue and alertness of patients. Longer postoperative follow-up with larger patient groups are needed to study further development of task-related ECT/min values after neurosurgery and can the effect of task on ECT/min predict working ability.
Kiti Muller is a Neurologist with a PhD in Neuroimmunology. She is the Senior Neuroscientist at Nokia Bell Labs; Adjunct Professor in Neurology at Helsinki University and; in Cognitive Neuro-ergonomics at Aalto University, School of Science. Her research in Cognitive Neurophysiology focuses on sleep, fatigue and vigilance in different medical conditions and their effects on working ability of patients.