Critical Care Medicine | 2019
743: THE INFLUENCE OF PERIODIC DISCHARGES ON EXECUTIVE FUNCTIONING AFTER TRAUMATIC BRAIN INJURY
Abstract
Learning Objectives: Traumatic brain injury is known to affect long-term cognitive outcome of patients. We hypothesized that abnormalities on EEG would also be associated with cognitive outcome in patients with moderate-to-severe TBI in a post-hoc analysis of a prospective, randomized multicenter trial. Methods: Validated cEEG terminology was used by a certified rater blinded to clinical data. The presence of normal EEG features (posterior dominant rhythm, sleep transients) were identified. The ictal-interictal continuum (IIC) was defined as ≥1.5 Hz lateralized rhythmic delta activity or generalized periodic discharges, and any lateralized periodic discharges or seizures. IIC burden was calculated in Hz/Hr based on published criteria. Executive functioning was assessed using the Trail Making Test (TMT) A & B at oneand three-months following injury. Results: A total of 152 patients with moderate-to-severe TBI were enrolled and underwent cEEG recording. The mean age was 34.5 (SD ±14.8) years and 85 (96%) were men. The median (interquartile range) admission GCS was 7 (7–9) and admission ISS was 24 (12–29). 133/152 survived and the TMT A/B at 1 month was completed by 70 and 67 patients, respectively while the TMT A/B at 3 months were completed by 92 and 91, respectively. With regard to background EEG characteristics, the presence of a PDR or sleep transients did not correlate with TMT A/B completion times at either 1or 3-months. The IIC burden was positively correlated with the time to complete TMT B at 1 month (Spearman rho=0.786; p=0.036) but not at 3 months (r=0.093; p=0.762); there was no correlation with TMT A (1 month r=0.133; p=0.732 and 3 month r=0.157; p=0.609). Conclusions: In this work, we found that the IIC burden impacted executive processing speed at 1-month but not 3-months. In contrast to prior work, which found that EEG background characteristics were asociated with functional outcome and that IIC burden was associated with 3-month global cognitive functioning, our data may suggest time-dependent effect of seizures and abnormal periodic or rhythmic discharges on specific cognitive domains.