Are visual functions diagnostic signs of the minimally conscious state? an integrative review
Overbeek, B.U.H., Eilander, H.J., Lavrijsen, J.C.M., & Koopmans, R.T.C.M.
5 februari 2017Abstract
Visual pursuit (VP) and visual fxation (VF) have been recognized as the frst signs of emerging consciousness and, therefore, are considered indicative of the minimally conscious state (MCS). However, debate exists about their status as they are
considered either conscious reactions or refexes. The aim of this study is to review the evidence of the defnition, operationalization, and assessment of VP and VF in unconscious patients. PubMed and EMBASE were searched for relevant papers
between May 26, 1994 and October 1, 2016. In addition, an internet search was done to identify other relevant papers, reports
and manuals of assessment methods. Papers were included if the defnition, operationalization, or assessment method of VP
and VF was discussed in patients with disorders of consciousness. We identifed 2364 articles, of which 38 were included.
No uniform defnitions of VP and VF were found. VP and VF were operationalized diferently, depending on which scale
was used. The Coma Recovery Scale-revised and the Sensory Tool to Assess Responsiveness were the only diagnostic scales
found; the other scales were developed to monitor DOC patients. The use of a mirror was the most sensitive method for
detecting VP and VF. The literature about the importance VP and VF in relation with consciousness is controversial. This
integrative review shows a lack of consensus regarding the defnition, operationalization, and assessment of VP and VF.
International consensus development about the defnition, operationalization, and assessment of VP and VF is recommended.
