title: Neuronal damage after ischemic injury in the middle cerebral arterial territory: deep watershed versus territorial infarction at MR perfusion and spectroscopic imaging.
abstract: OBJECTIVE
  To determine the temporal patterns of neuronal injury between infarction subtypes and their possible association with changes in cerebral blood volume (CBV).
  
  
  METHODS
  Twenty-five patients with ischemic injuries of middle cerebral arterial territories and receiving only conservative treatments were classified into territorial infarction (TI) (n = 16) and watershed infarction (WI) (n = 9) groups and were prospectively evaluated with longitudinal magnetic resonance (MR) examinations. Each patient underwent as many as five MR studies at various stroke stages following stroke symptom onset. Dynamic susceptibility-weighted contrast material-enhanced MR imaging was performed to yield the relative CBV (rCBV). Chemical shift imaging was used to measure the relative levels of N-acetylaspartate (NAA) and lactate of the ischemic brain tissue. Repeated-measures analysis of variance was used to examine the statistical significance in evolutional differences between TI and WI.
  
  
  RESULTS
  For patients with TI, rCBV followed a progressively increasing pattern, from initial low values (0.46 +/- 0.28 [SD]) to peak high values (1.23 +/- 0.34) at early chronic stage. Relative NAA level decreased to 0.40 +/- 0.24 during acute stroke and was lost completely 4 days after ictus. Patients with WI showed consistently high rCBV throughout all stages, with residual relative NAA level (0.53 +/- 0.25) even at 1 month after symptom onset. Relative lactate level of patients with TI was significantly higher than that of patients with WI at the acute stage (P <.01). Differences in the temporal changes of both rCBV and brain metabolites between TI and WI were significant (P <.01).
  
  
  CONCLUSIONS
  The different temporal patterns for stroke progression in TI and WI are associated with different evolutions of hemodynamics and neuronal injury.
mesh_terms: D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D001810:Blood Volume; D001921:Brain / Q000473:pathology*; D001923:Brain Chemistry; D002545:Brain Ischemia / Q000175:diagnosis*; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000175:diagnosis* / Q000378:metabolism; D019344:Lactic Acid / Q000032:analysis; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000473:pathology; D013997:Time Factors
chemical_list: D003287:Contrast Media; D001224:Aspartic Acid; D019344:Lactic Acid; C000179:N-acetylaspartate