title: The role of brain MRI in mitochondrial neurogastrointestinal encephalomyopathy.
abstract: Leukoencephalopathy is a hallmark of mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) a devastating disorder characterized by ptosis, ophthalmoparesis, gastrointestinal dysfunction and polyneuropathy. To characterize MNGIE-associated leukoencephalopathy and to correlate it with clinical, biochemical and molecular data, four MNGIE patients with heterogeneous clinical phenotypes (enteropathic arthritis, exercise intolerance, CIDP-like phenotype and typical presentation) were studied by magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Diffusion weighted imaging (DWI) with apparent diffusion coefficient (ADC) maps were also obtained. In two patients we also investigated the role of brain MRI in monitoring the evolution of leukoencephalopathy by performing follow-up imaging studies at an interval of one and two years. The extension and distribution of leukoencephalopathy were not clearly linked with age, phenotype or disease severity, and did not seem to be related to TYMP mutations, enzyme activity or pyrimidine levels. In the studied patients MRS revealed reduced N-acetyl-aspartate and increased choline signals. Although DWI appeared normal in all patients but one, ADC maps always showed moderate increased diffusivity. Leukoencephalopathy worsened over a two-year period in two patients, regardless of the clinical course, indicating a lack of correlation between clinical phenotype, size and progression of white matter abnormalities during this period. Brain MRI should be considered a very useful tool to diagnose both classical and atypical MNGIE. Serial MRIs in untreated and treated MNGIE patients will help to establish whether the leukoencephalopathy is a reversible condition or not.
authors.affiliation: Department of Neurological and Movement Sciences, Section of Neurology, University of Verona; Verona, Italy - mauro.scarpelli@univr.it.
authors.forename: Mauro
authors.initials: M
authors.lastname: Scarpelli
authors.forename: Giuseppe Kenneth
authors.initials: GK
authors.lastname: Ricciardi
authors.forename: Alberto
authors.initials: A
authors.lastname: Beltramello
authors.forename: Isabella
authors.initials: I
authors.lastname: Zocca
authors.forename: Francesca
authors.initials: F
authors.lastname: Calabria
authors.forename: Anna
authors.initials: A
authors.lastname: Russignan
authors.forename: Francesca
authors.initials: F
authors.lastname: Zappini
authors.forename: Maria Sofia
authors.initials: MS
authors.lastname: Cotelli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Padovani
authors.forename: Giuliano
authors.initials: G
authors.lastname: Tomelleri
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Filosto
authors.forename: Paola
authors.initials: P
authors.lastname: Tonin
mesh_terms: D000328:Adult; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007418:Intestinal Pseudo-Obstruction / Q000378:metabolism / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D017237:Mitochondrial Encephalomyopathies / Q000378:metabolism / Q000473:pathology*; D039141:Muscular Dystrophy, Oculopharyngeal; D009886:Ophthalmoplegia / Q000151:congenital; D010641:Phenotype; D028361:Mitochondrial Diseases
keywords: DWI; MNGIE; MRI; MRS; mitochondrial neurogastrointestinal encephalomyopathy; posterior reversible encephalopathy syndrome