The minimally conscious state

Abstract

Abstract-Objective:To establish consensus recommendations among health care specialties for defining and establishing diagnostic criteria for the minimally conscious state (MCS). Background: There is a subgroup of patients with severe alteration in consciousness who do not meet diagnostic criteria for coma or the vegetative state (VS). These patients demonstrate inconsistent but discernible evidence of consciousness. It is important to distinguish patients in MCS from those in coma and VS because preliminary findings suggest that there are meaningful differences in outcome. Methods: An evidence-based literature review of disorders of consciousness was completed to define MCS, develop diagnostic criteria for entry into MCS, and identify markers for emergence to higher levels of cognitive function. Results: There were insufficient data to establish evidence-based guidelines for diagnosis, prognosis, and management of MCS. Therefore, a consensusbased case definition with behaviorally referenced diagnostic criteria was formulated to facilitate future empirical investigation. Conclusions: MCS is characterized by inconsistent but clearly discernible behavioral evidence of consciousness and can be distinguished from coma and VS by documenting the presence of specific behavioral features not found in either of these conditions. Patients may evolve to MCS from coma or VS after acute brain injury. MCS may also result from degenerative or congenital nervous system disorders. This condition is often transient but may also exist as a permanent outcome. Defining MCS should promote further research on its epidemiology, neuropathology, natural history, and management.

Stratification of unresponsive patients by an independently validated index of brain complexity

“…Although MCS patients are unable to provide a verbal report about their subjective experience, they show behavioral signs of consciousness 1, 29. The presence of such signs, albeit fluctuating, can be considered as a minimal standard against which the sensitivity of any candidate index of consciousness should be tested.…”

Divergent neural responses to narrative speech in disorders of consciousness

“…Subscale scores from each patient's highest CRS‐R and command following data from functional neuroimaging were assessed by an expert neurologist (senior author NS) to codify clinical diagnoses of VS, MCS−/+, or eMCS according to the following criteria: patients may remain wakeful but unresponsive to the external world in the persistent VS 30. Others in the MCS may have inconsistent responses to their surroundings 31. This category is subdivided into plus/minus, with MCS‐ designating individuals with exclusively low‐level, reflexive behavior such as withdrawing from pain or turning toward sound.…”

Severe Brain Injury and Organ Solicitation: A Call for Temperance

“…According to the Aspen Criteria of 2002 [8], MCS patients demonstrate unequivocal, but fluctuating, evidence of awareness of self and the environment. They may say words or phrases and may gesture.…”