Assessment of command-following in minimally conscious brain injured patients

Objective: To develop a method for establishing the presence of command-fol lowing in individuals with traumatic brain injury, based on the principles of single-subject experimental design. Design: A series of single-subject experiments, individualized to the parti cular command-following question about a particular patient. Setting: An inpatient rehabilitation hospital with a specialized program fo r vegetative and minimally conscious brain injured patients. Patients: Eight individuals with serious brain injury of traumatic or nontr aumatic origin, presenting in vegetative or minimally conscious states. Interventions: The frequency of performance of the behavior in question was assessed in response to commands and in relation to appropriate control co nditions. Data were analyzed with chi(2) Or Fisher's exact test, as well as measures derived from signal detection theory. Main Outcome Measures: The frequency of performance of a specific behavior in the presence of a command and in relevant contrasting conditions. Results: This method identified whether a specific behavior was being perfo rmed in response to command and whether the reliability of this behavior wa s changing over time either spontaneously or in response to treatment. Conclusions: Quantitative assessment of command-following based on principl es of single-subject experimental design can determine whether patients are capable of following commands and whether this ability changes over time o r in response to treatment. (C) 1999 by the American Congress of Rehabilita tion Medicine and the American Academy of Physical Medicine and Rehabilitat ion.