For professionals

Abstract

Visual chase (VP) and visual fixation (VF) have been recognized as the first signs of emerging consciousness and are therefore considered indicative of the minimally conscious state (MCS). However, there is debate about their status, as they are considered conscious reactions or reflexes.

The purpose of this study is to assess the evidence of the definition, operationalization, and assessment of VP and VF in unconscious patients.

PubMed and EMBASE were searched for relevant papers between 26 May 1994 and 1 October 2016. In addition, other relevant papers, reports and manuals of assessment methods were searched on the internet. Papers were included if the definition, operationalization, or assessment method of VP and VF was discussed in patients with disorders of consciousness.

We identified 2364 articles, of which 38 were included. No uniform definitions of VP and VF were found. VP and VF were operationalized differently depending on which scale was used. The revised Coma Recovery Scale 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 on the importance of VP and VF in relation to consciousness is controversial.

This integrative review shows a lack of consensus on the definition, operationalization, and assessment of VP and VF. International consensus development on the definition, operationalization and assessment of VP and VF is recommended.

Keywords
Disturbances of consciousness, Minimal conscious state, Visual pursuit, Visual fixation