Higher pre-morbid intelligence (IQ) and younger age are linked with greater cognitive recovery after complicated mild-to-severe traumatic brain injury (TBI), according to new research published in the Journal of Neurotrauma. However, the duration of post-traumatic amnesia (PTA) after TBI may not predict cognitive recovery.
The longitudinal study included 109 adults with mild-to-severe TBI whose age, IQ and injury severity measured by PTA duration were recorded.
Participants completed measures of pre-morbid IQ, attention, memory, and executive function at a mean of 44 days post-TBI and again at a mean of 3.70 years post-injury. A healthy control group comprising 63 adults completed the measures once.
At the initial assessment, TBI participants performed significantly worse on all measures compared with the healthy controls as expected but recorded significant improvements in cognitive performance between initial and follow-up assessment.
The authors found that within the TBI group, shorter PTA duration, younger age and higher pre-morbid IQ were associated with better initial cognitive performance. At follow-up, only higher pre-morbid IQ and younger age were associated with greater cognitive recovery.
“These findings support the role of cognitive reserve and age in cognitive recovery after TBI and may inform prognostication and rehabilitation,” the authors said.