Agitation following traumatic head injury: equivocal evidence for a discrete stage of cognitive recovery.

Agitation and confusion appear to be associated in the early period of recovery from traumatic head injury. Eighteen severely head-injured patients were assessed during acute rehabilitation for both the extent of agitation and level of cognitive functioning. Agitation was measured by the Agitated Behavior Scale developed by Corrigan. Simultaneous independent measurements of cognitive functioning were obtained from the Orientation Group Monitoring System and Mini-Mental State. Agitation was significantly correlated with both measures of cognitive functioning, indicating that as cognition improved, agitation diminished. Agitation was partitioned into high and low levels, and cognitive functioning was partitioned into low, middle, and high levels for each of the two measures of cognitive functioning. Chi-square analysis of the distribution of agitation and cognition indicated significant differentiation, with high agitation prevalent in low levels of cognition, and low agitation prevalent in high levels of cognition. Patients in the middle level of cognition were equally likely to demonstrate high and low agitation. Further descriptive analysis indicated that improvement from low levels of cognition preceded improved agitation, and improved agitation preceded clearing from posttraumatic amnesia. These results provide equivocal support for the long-held clinical observation that a period of pronounced confusion and agitation represents a discrete stage of recovery from traumatic head injury.