title: Crossed cerebellar diaschisis in patients with cortical infarction: logistic regression analysis to control for confounding effects.
abstract: OBJECTIVE
  Crossed cerebellar diaschisis (CCD) refers to reduced metabolism and blood flow in the cerebellar hemisphere contralateral to a cerebral lesion. Many cortical areas have been reported to cause CCD without consideration of confounding factors. We performed single-photon emission computed tomography (SPECT) in patients with cortical infarction to identify regions independently related to CCD, controlling for possible confounding effects.
  
  
  METHODS
  Patients with unilateral cortical infarction (n=113; 75 male, 38 female; mean+/-SD age, 66+/-13 years) underwent SPECT of the brain with N-isopropyl-p-[(123)I]iodoamphetamine ((123)I-IMP). Regional cerebral blood flow was measured autoradiographically. Asymmetry indices (AIs) were calculated on the basis of ratios representing symmetrical regional cerebral blood flow in the cerebellum and 16 cerebral regions. CCD was defined as AI for cerebellum >0.1. AIs for 16 cortical regions were considered for both dichotomous and continuous variables for analysis of CCD occurrence by means of backward logistic regression.
  
  
  RESULTS
  For dichotomized variables, hypoperfusion of postcentral (odds ratio [OR]=7.607; 95% CI, 2.299 to 25.174) and supramarginal (OR=3.916; 95% CI, 1.394 to 11.003) regions independently influenced CCD. For continuous variables, hypoperfusion of postcentral (OR=1.044; 95% CI, 1.019 to 1.068) and supramarginal (OR=1.021; 95% CI, 1.001 to 1.041) regions (and, as a negative factor, medial occipital regions; OR=0.942; 95% CI, 0.895 to 0.991) independently influenced CCD.
  
  
  CONCLUSIONS
  Many cortical areas apparently do not contribute to CCD. Correspondence of CCD between dichotomized and continuous analyses suggests that location of a lesion, not severity, is the main determinant of CCD.
authors.affiliation: Second Department of Internal Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Komaba
authors.forename: Masahiro
authors.initials: M
authors.lastname: Mishina
authors.forename: Kouichi
authors.initials: K
authors.lastname: Utsumi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Katayama
authors.forename: Shiro
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Osamu
authors.initials: O
authors.lastname: Mori
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D002531:Cerebellum / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002544:Cerebral Infarction / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007457:Iodine Radioisotopes; D020367:Iofetamine; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D007457:Iodine Radioisotopes; D020367:Iofetamine