title: MRI Susceptibility Changes Suggestive of Iron Deposition in the Thalamus after Ischemic Stroke.
abstract: BACKGROUND
  Iron accumulation has been linked to neuronal injury following cerebral ischemia. In animals, a hypointense signal on T2*-weighted (T2*-w) MRI correlated with iron deposits in remote brain regions following ischemic stroke. We aim to assess whether such signal changes are present in remote brain structures following ischemic stroke in humans.
  
  
  METHODS
  We analyzed T2*-w images of 36 patients with unilateral ischemic stroke and 36 healthy controls. Regions of interest (ROIs) consisted of the thalamus, putamen, globus pallidus, caudate nucleus and white matter. To quantify signal intensity in ROIs ipsilateral to the infarct, signal intensity was measured in the ROIs in both hemispheres and a ratio of signal intensity was calculated. Signal asymmetry was compared between patients and controls and its relation with time after stroke onset was assessed.
  
  
  RESULTS
  In 34 (94%) patients, the thalamus ipsilateral to the infarct was hypointense compared to the contralateral thalamus. Ipsilateral thalamic signal hypointensity was significantly different between patients and controls (p < 0.001) and was present as early as 1 day after stroke onset. In other ROIs, no difference was found between patients and controls. No association was found between intensity asymmetry and time.
  
  
  CONCLUSIONS
  We demonstrated that, as early as days after ischemic stroke, T2*-w signal intensity was decreased in the ipsilateral thalamus. This finding might indicate pathophysiologic changes in regions outside the infarcted area, possibly reflecting toxic iron accumulation.
authors.affiliation: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Ellis S
authors.initials: ES
authors.lastname: van Etten
authors.forename: Jeroen
authors.initials: J
authors.lastname: van der Grond
authors.forename: Eve M
authors.initials: EM
authors.lastname: Dumas
authors.forename: Simon J A
authors.initials: SJ
authors.lastname: van den Bogaard
authors.forename: Mark A
authors.initials: MA
authors.lastname: van Buchem
authors.forename: Marieke J H
authors.initials: MJ
authors.lastname: Wermer
mesh_terms: D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis / Q000378:metabolism*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D020521:Stroke / Q000175:diagnosis / Q000378:metabolism*; D013788:Thalamus / Q000378:metabolism*; D013997:Time Factors
chemical_list: D007501:Iron