The First 100 Days: Trajectory of Relational Memory Ability After Traumatic Brain Injury

Abstract

At least 2.5 million people acquire a traumatic brain injury (TBI) every year; the incidence is plausibly higher, considering not everyone seeks medical attention. The impairment in relational (declarative) memory that often accompanies TBI can greatly impact recovery and future functioning. These deficits in memory can be a barrier to rehabilitative success (i.e., may impede learning of compensatory strategies and medication management). Traditional assessments, both formal and informal, of relational (declarative) memory are possibly impacted by other disrupted functions after TBI due to reduced sensitivity. These measures are used to make clinical decisions during the immediate acute stage of injury that have long-term effects on functional outcomes. The acute phase (i.e., first 100 days) after a TBI is a time of rapid change, and ability in this period is used to predict long-term cognitive functioning. However, little is known about how memory changes over this period in the TBI population. A longitudinal study was undertaken measuring relational (declarative) memory to examine how it changes over time during the acute stage of TBI. This measurement was approached using a promising research tool, a spatial reconstruction (SR) task. It was first necessary to establish the feasibility of using an SR Task with the acute TBI population soon after injury. It was demonstrated that the SR Task was feasible in an acute setting, could be administered remotely for patients with TBI who were quickly discharged to another setting, and was sensitive to the presence of relational memory impairment between individuals with and without TBI (acute and chronic). Further usage of the SR Task over time revealed initial evidence of general group improvement in SR Task accuracy. Within the general group trajectory, there were individual participants who seemed to demonstrate degradation or stable relational memory ability. This is suggestive of the distinct subgroups observed in chronic TBI trajectory over time may be present early after injury. This work supports continued evaluation of changes in memory during the acute phase of injury to better inform clinical recommendations for individuals with TBI both in the acute and chronic phases of injury.