title: Arteriovenous brain malformations: is functional MR imaging reliable for studying language reorganization in patients? Initial observations.
abstract: OBJECTIVE
  To determine whether the blood flow abnormalities frequently associated with arteriovenous malformations (AVMs) can alter functional magnetic resonance (MR) imaging evaluation of language lateralization and whether reorganization of language function occurs in patients with brain AVMs.
  
  
  METHODS
  Eleven patients with left-hemisphere brain AVMs and 10 age-matched control subjects were examined with 1.5-T blood oxygen level-dependent (BOLD) functional MR imaging. Verbal fluency, sentence repetition, and story listening tasks were performed. The functional MR imaging laterality index in the frontal and temporal lobes was defined as the (L - R)/(L + R) ratio, where L and R are the numbers of activated pixels in the left and right hemispheres, respectively. Statistical analyses were performed with Wilcoxon signed rank, Fisher exact, and Kruskal-Wallis tests.
  
  
  RESULTS
  Control subjects had left-sided language dominance, although symmetric pixel counts were observed in the frontal lobes in two subjects and in the temporal lobes in one subject. Six patients had left-sided language dominance similar to that observed in control subjects. Five of these patients had AVMs outside frontal or temporal language areas, without flow abnormalities. Five patients had abnormally right-sided asymmetric indexes (below mean control subject value - 2 SDs), which suggested language reorganization (P <.05). Results of Wada examination and/or postembolization functional MR imaging performed in two of these patients showed that the abnormal laterality indexes were at least partly due to severe flow abnormalities that impaired detection of BOLD MR imaging signal intensity.
  
  
  CONCLUSIONS
  These data suggest that flow abnormalities may interfere with language lateralization assessment with functional MR imaging.
authors.affiliation: Department of Neuroradiology, Hôpital de la Salpêtrière, 47 Boulevard de l'Hôpital, 75013 Paris, France. stephane.lehericy@psl.ap-hop-paris.fr
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lehéricy
authors.forename: Alessandra
authors.initials: A
authors.lastname: Biondi
authors.forename: Nader
authors.initials: N
authors.lastname: Sourour
authors.forename: Michaela
authors.initials: M
authors.lastname: Vlaicu
authors.forename: Sophie Tézenas
authors.initials: ST
authors.lastname: du Montcel
authors.forename: Laurent
authors.initials: L
authors.lastname: Cohen
authors.forename: Elio
authors.initials: E
authors.lastname: Vivas
authors.forename: Laurent
authors.initials: L
authors.lastname: Capelle
authors.forename: Thierry
authors.initials: T
authors.lastname: Faillot
authors.forename: Alfredo
authors.initials: A
authors.lastname: Casasco
authors.forename: Denis
authors.initials: D
authors.lastname: Le Bihan
authors.forename: Claude
authors.initials: C
authors.lastname: Marsault
mesh_terms: D000328:Adult; D015901:Angiography, Digital Subtraction; D001931:Brain Mapping; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D004292:Dominance, Cerebral; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002538:Intracranial Arteriovenous Malformations / Q000503:physiopathology*; D007807:Language Tests; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D013067:Speech Perception; D018709:Statistics, Nonparametric; D013702:Temporal Lobe / Q000503:physiopathology*