Hippocampal MRI Signal Hyperintensity After Febrile Status Epilepticus Is Predictive of Subsequent Mesial Temporal Sclerosis

• Published in: American journal of roentgenology (1976) Vol. 190; no. 4; pp. 976 - 983
• Main Authors: Provenzale, James M, Barboriak, Daniel P, VanLandingham, Kevan, MacFall, James, Delong, David, Lewis, Darrell V
• Format: Journal Article
• Language: English
• Published: Leesburg, VA Am Roentgen Ray Soc 01.04.2008; American Roentgen Ray Society
• Subjects: Biological and medical sciences; Child; Child, Preschool; Epilepsy, Temporal Lobe - etiology; Epilepsy, Temporal Lobe - pathology; Female; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Hippocampus - pathology; Humans; Infant; Investigative techniques, diagnostic techniques (general aspects); Linear Models; Magnetic Resonance Imaging - methods; Male; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Prospective Studies; Sclerosis - etiology; Sclerosis - pathology; Seizures, Febrile - complications; Seizures, Febrile - pathology; Status Epilepticus - complications; Status Epilepticus - pathology; Nuclear medicine; Nervous system diseases; Epilepsy; Nuclear magnetic resonance imaging; Fever; Sclerosis; Cerebral disorder; Subintrant crisis; Central nervous system disease; Radiology; Medical imagery; Predictive factor; Status epilepticus; Hippocampus
• ISSN: 0361-803X; 1546-3141; 1546-3141
• DOI: 10.2214/AJR.07.2407

The objective of our study was to test the hypothesis that the finding of hyperintense hippocampal signal intensity on T2-weighted MR images soon after febrile status epilepticus is associated with subsequent hippocampal volume loss and persistent abnormal signal intensity on T2-weighted images (i.e., mesial temporal sclerosis). Eleven children (mean age, 25 months) underwent initial MRI that included coronal temporal lobe imaging within 72 hours of febrile status epilepticus and follow-up imaging from 3 to 23 months later (mean, 9 months). A neuroradiologist blinded to clinical history graded initial and follow-up hippocampal signal intensity on a scale from 0 (normal) to 4 (markedly increased). Two blinded observers measured hippocampal volumes on initial and follow-up MR studies using commercially available software and volumes from 30 healthy children (mean age, 6.3 years). Initial signal intensity and hippocampal volume changes were compared using Kendall tau correlation coefficients. On initial imaging, hyperintense signal intensity ranging from 1 (minimally increased) to 4 (markedly increased) was seen in seven children. Four children had at least one hippocampus with moderate or marked signal abnormality, three children had a hippocampus with mild or minimal abnormality, and four children had normal signal intensity. The Kendall tau correlation coefficient between signal intensity increase and volume change was -0.68 (p < 0.01). Five children (two with temporal lobe epilepsy and two with complex partial seizures) had hippocampal volume loss and increased signal intensity on follow-up imaging, meeting the criteria for mesial temporal sclerosis. MRI findings of a markedly hyperintense hippocampus in children with febrile status epilepticus was highly associated with subsequent mesial temporal sclerosis.