title: Temporal lobe epilepsy with hippocampal sclerosis in acute lymphoblastic leukemia.
abstract: Of 71 acute lymphoblastic leukemia survivors at our hospital over the past 10 years, 2 children developed mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). This is the first report to describe the clinical course of MTLE-HS observed longitudinally by EEG and MRI. Patient 1 experienced a seizure during chemotherapy involving intrathecal methotrexate. Postseizure MRI suggested methotrexate encephalopathy or leukemic invasion. Anticonvulsant therapy was initiated; subsequent EEGs and MRIs revealed normal results. Three years after chemotherapy, a diffuse, irregular spike-and-wave pattern was observed on interictal EEG. Five years after chemotherapy, the patient developed MTLE-HS comprising complex partial seizures, typical temporal spikes on EEG, and hippocampal sclerosis (HS). Patient 2 did not experience seizures during chemotherapy. Four years later, the patient started experiencing complex partial seizures, and a diffuse, irregular spike-and-wave pattern was observed on interictal EEG. A clinical picture of MTLE-HS developed 2 years later. In both patients, nonspecific EEG abnormalities (ie, diffuse, irregular spike-and-wave activity) preceded the appearance of HS on MRI by 2 years, suggesting an insidious advance of HS during the latent period. Such atypical EEG findings may indicate MTLE-HS during follow-up of leukemia patients. MTLE-HS develops several years after an initial precipitating incident such as prolonged seizures, central nervous system infection, and brain trauma. In our cases, the initial precipitating incident may have been chemotherapy and/or prolonged seizures. Thus, MTLE-HS associated with leukemia may not be as rare as generally believed. A large cohort study of late neurologic complications is warranted.
authors.affiliation: Departments of Pediatrics, St Luke’s International Hospital, Chuo-ku, Tokyo, Japan. kasai-sin@umin.ac.jp
authors.forename: Emi
authors.initials: E
authors.lastname: Kasai-Yoshida
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ogihara
authors.forename: Miwa
authors.initials: M
authors.lastname: Ozawa
authors.forename: Taiki
authors.initials: T
authors.lastname: Nozaki
authors.forename: Michiharu
authors.initials: M
authors.lastname: Morino
authors.forename: Atsushi
authors.initials: A
authors.lastname: Manabe
authors.forename: Ryota
authors.initials: R
authors.lastname: Hosoya
mesh_terms: D000927:Anticonvulsants / Q000009:adverse effects / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects* / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004334:Drug Administration Schedule; D004569:Electroencephalography / Q000187:drug effects; D017029:Epilepsy, Complex Partial / Q000139:chemically induced / Q000175:diagnosis / Q000188:drug therapy; D004833:Epilepsy, Temporal Lobe / Q000139:chemically induced* / Q000175:diagnosis* / Q000188:drug therapy; D005260:Female; D005500:Follow-Up Studies; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007278:Injections, Spinal; D008279:Magnetic Resonance Imaging; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage / Q000009:adverse effects; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis / Q000188:drug therapy*; D012598:Sclerosis / Q000139:chemically induced / Q000175:diagnosis
chemical_list: D000927:Anticonvulsants; D008727:Methotrexate
keywords: MRI; electroencephalography; leukemia; methotrexate; temporal lobe epilepsy