Study investigated the relationship between three language-dependent behaviors (command-following, intelligible verbalization, and intentional communication) and the functional status of patients with disorders of consciousness (DoC). It was hypothesized that patients in minimally conscious state (MCS) who retain behavioral evidence of preserved language function would have similar levels of functional disability, while patients who lack these behaviors would demonstrate significantly greater disability. The acquired data could be used to establish empirically based diagnostic criteria for designating patients as MCS positive (MCS+), defined by the presence of command-following, intelligible verbalization, or gestural or verbal yes/no intentional communication; or MCS negative (MCS−). The study included rehabilitation inpatients diagnosed with DoC following severe-acquired brain injury: 57 in MCS, 63 vegetative state/unresponsive wakefulness syndrome (VS/UWS). The scores of the Disability Rating Scale score (DRS) were compared at time of transition from VS/UWS to MCS or from MCS− to MCS+, and at discharge between groups. Level of disability on the DRS was similar in patients with any combination of the three language-related behaviors. MCS patients with no behavioral evidence of language function (i.e., MCS−) were more functionally impaired than patients with MCS+ at time of transition and at discharge. Findings suggest that command-following, intelligible verbalization, and intentional communication are not associated with different levels of functional disability. Thus, the MCS+ syndrome can be diagnosed based on the presence of any one of these language-related behaviors. Patients in MCS+ may evidence less functional disability compared to those in MCS who fail to demonstrate language function (i.e., MCS−).
Thibaut, Aurore |Bodien, Yelena G. |Laureys, Steven|Giacino, Joseph T.|