title: A review on radiogenic Lhermitte's sign.
abstract: Radiation myelopathy is a rare, but extremely serious side-effect of radiotherapy. Recovery from radiation-induced motor sequelae is rare, whereas, the regeneration of sensory losses is relatively frequent. Among the sensory radiogenic injuries of the spinal cord, Lhermitte's sign (LS) is most frequent. This review describes the clinical picture and diagnostic imaging signs of radiogenic LS. There have been only a few studies on large patient groups with radiogenic LS, demonstrating a rate of occurrence of 3.6-13%, relating mainly to mantle irradiation or the radiotherapy of head and neck tumors. These cases typically manifest themselves 3 months following radiotherapy and gradually disappear within 6 months. Only 3 LS cases have been described in the English literature with extraordinarily severe symptoms lasting for more than 1 year. MRI, a sensitive tool in the detection of demyelination, failed to reveal any pathological sign accompanying radiogenic LS. However, positron emission tomography demonstrated increased [18F]fluorodeoxyglucose accumulation and [15O]butanol perfusion, but a negligible [11C]methionine uptake in the irradiated spinal cord segments in patients with long-standing LS. These imaging data are suggestive of a close direct relationship between the regional perfusion and metabolism of the spinal cord, very much like the situation in the brain. We postulate that an altered, energy-demanding conduction along the demyelinated axons of patients with chronic radiogenic LS may explain the increased metabolism and perfusion.
authors.affiliation: Department of Oncotherapy, Semmelweis University, H-1122 Budapest, Hungary. esik@oncol.hu
authors.forename: Olga
authors.initials: O
authors.lastname: Esik
authors.forename: Tibor
authors.initials: T
authors.lastname: Csere
authors.forename: Klára
authors.initials: K
authors.lastname: Stefanits
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Lengyel
authors.forename: Géza
authors.initials: G
authors.lastname: Sáfrány
authors.forename: Katalin
authors.initials: K
authors.lastname: Vönöczky
authors.forename: Erzsébet
authors.initials: E
authors.lastname: Lengyel
authors.forename: Csaba
authors.initials: C
authors.lastname: Nemeskéri
authors.forename: Imre
authors.initials: I
authors.lastname: Repa
authors.forename: Lajos
authors.initials: L
authors.lastname: Trón
mesh_terms: D000440:Butanols / Q000378:metabolism; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006801:Humans; D008715:Methionine / Q000378:metabolism; D011832:Radiation Injuries / Q000175:diagnosis* / Q000378:metabolism; D011878:Radiotherapy / Q000009:adverse effects*; D013116:Spinal Cord / Q000378:metabolism / Q000528:radiation effects*; D013118:Spinal Cord Diseases / Q000175:diagnosis* / Q000378:metabolism
chemical_list: D000440:Butanols; D019788:Fluorodeoxyglucose F18; D008715:Methionine