Assessment of visual fixation in vegetative and minimally conscious states
- Equal contributors
1 International Vegetative State and Consciousness Science Institute, Hangzhou Normal University, 310036 Hangzhou, China
2 Cyclotron Research Centre and Neurology Department, Coma Science Group, University and University Hospital of Liege, Liege, Belgium
3 Wujing Hospital of Hangzhou City, Hangzhou, China
4 Huzhou Center Hospital, Huzhou, China
BMC Neurology 2014, 14:147 doi:10.1186/1471-2377-14-147Published: 16 July 2014
Visual fixation plays a key role in the differentiation between vegetative state/unresponsive wakefulness (VS/UWS) syndrome and minimally conscious state (MCS). However, the use of different stimuli changes the frequency of visual fixation occured in patients, thereby possibly affecting the accuracy of the diagnosis. In order to establish a standardized assessment of visual fixation in patients in disorders of consciousness (DOC), we compared the frequency of visual fixation elicited by mirror,a ball and a light.
Visual fixation was assessed in eighty-one post-comatose patients diagnosed with a MCS or VS/UWS. Occurrence of fixation to different stimuli was analysis used Chi-square testing.
40 (49%) out of the 81 patients showed fixation to visual stimuli. Among those, significantly more patients (39, 48%) had visual fixation elicited by mirror compared to a ball (23, 28%) and mirror compared to a light (20, 25%).
The use of a mirror during the assessment of visual fixation showed higher positive response rate, compared to other stimuli in eliciting a visual fixating response. Therefore, fixation elicited by a mirror can be a very sensitive and accurate test to differentiate the two disorders of consciousness.