MRI Biomarkers for Post-traumatic Epileptogenesis

The present study tested a hypothesis that early identification of injury severity with quantitative magnetic resonance imaging (MRI) provides biomarkers for predicting increased seizure susceptibility and epileptogenesis after traumatic brain injury (TBI). TBI was induced by lateral fluid percussion injury (FPI) in adult rats. Quantitative T2, T1ρ, and diffusion were assessed with MRI at 9 days, 23 days, or 2 months post-TBI in the perilesional cortex, thalamus, and hippocampus. Seizure susceptibility was assessed at 12 months after TBI using the pentylenetetrazol seizure-susceptibility test. At 9 and 23 days post-TBI, a change in T1ρ of the perilesional cortex showed the greatest predictive value for increased seizure susceptibility at 12 months post-TBI [area under the curve (AUC), 0.929 and 0.952, respectively; p<0.01]. At 2 months post-TBI, Dav in the thalamus was the best of the biomarkers analyzed (AUC, 0.988; p<0.05). The highest predictive value of all biomarkers was achieved by combining the measurement of Dav in the perilesional cortex and the thalamus at 2 months post-TBI (AUC, 1.000; p<0.01). Our results provide proof-of-concept evidence that clinically relevant MRI biomarkers predict increased seizure susceptibility after experimental TBI.