MRI Manifestations of Hippocampus with Acute Injury in Children / 中国医学影像学杂志

ABSTRACT

Purpose To study the MRI manifestations of hippocampus with acute injury in children with epilepsy, and to explore its causes and outcomes for a better understanding of the changes of hippocampal structure with acute injury.Materials and Methods The clinical and imaging data of 8 children with epilepsy whose hippocampus showed hyperintensity in DWI were retrospectively analyzed. The bilateral hippocampal volume and ADC values were measured; changes of hippocampal volume and T2WI signal and ADC value were also analyzed.Results Eight patients were clinically diagnosed as epilepsy, 7 cases had recurrent history of seizures. MRI was performed from 1 to 5 days after the onset of epilepsy. All the 8 patients had increased unilateral hippocampal volume, 6 of whom were on the left side and the other 2 were on the right side. The affected ipsilateral hippocampal volume was significantly higher than that on the contralateral side [(2.096±0.570) cm3 and (1.768±0.447) cm3, respectively,t=-4.763,P<0.01]. The signals increased on T2WI and FLAIR; DWI showed hyperintensity with increase by approximately 25.52%. The affected ipsilateral ADC value was significantly lower than the contralateral one [(0.763±0.049)×10-3 mm2/s and (0.859±0.054)×10-3 mm2/s, respectively, t=9.598,P<0.01]. No abnormalities were found in bilateral hippocampus when 3 patients underwent MRI due to febrile convulsions and seizures before the onset of epilepsy. The affected ipsilateral hippocampal volume reduced in 3 patients after 3 to 5 months;signal was still high on T2WI and FLAIR; ADC values increased by 15.6%, the imaging results indicated hippocampal sclerosis.Conclusion Epilepsy can cause acute injury in hippocampus which demonstrates hippocampus swelling, signal increase on T2WI, and reduced ADC value and may lead to hippocampal sclerosis.