title: Asymptomatic versus symptomatic infarcts from vasospasm in patients with subarachnoid hemorrhage: serial magnetic resonance imaging.
abstract: OBJECTIVE
  By use of serial magnetic resonance imaging (MRI), we prospectively investigated the incidence of and the risk factors associated with infarction caused by vasospasm with or without a delayed ischemic neurological deficit (DIND) in patients with subarachnoid hemorrhage (SAH).
  
  
  METHODS
  In 125 patients who underwent surgery for early aneurysms, postoperative MRI scans were obtained at four time points. We defined an infarct from vasospasm as a new lesion not present on the initial MRI within 3 days after SAH and therefore not attributable to primary brain damage or surgical complications.
  
  
  RESULTS
  Overall, symptoms of infarction (i.e., DIND) occurred in 38% of patients (48 of 125); DIND with a new infarct on MRI was evident in 34% (43 patients), whereas 4% (5 patients) showed no new lesion but had a DIND. However, 29 patients (23%) showed a new infarct but no DIND on MRI studies (asymptomatic infarction). Asymptomatic ischemic lesions due to vasospasm tended to involve noneloquent brain areas in the territory of intraparenchymal perforators. Multivariate analysis identified variables associated with symptomatic infarction to be of poor SAH grade, advanced age of the patient, angiographic findings of vasospasm, multiple cortical infarcts on MRI studies consistent with vasospasm, and chronic hydrocephalus.
  
  
  CONCLUSIONS
  Analysis of the data confirmed the occurrence of asymptomatic infarcts due to vasospasm. These infarcts often developed in noneloquent areas representing perforator territory. MRI investigation of vasospastic lesions referable to intraparenchymal vessels such as perforators complements the study of extraparenchymal major vessel vasospasm in patients with SAH by computed tomographic angiography.
authors.affiliation: Department of Neurosurgery, Tokai University School of Medicine, Bohseidai, Isehara, Kanagawa, Japan. m-shimo@is.icc.u-tokai.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Shimoda
authors.forename: M
authors.initials: M
authors.lastname: Takeuchi
authors.forename: J
authors.initials: J
authors.lastname: Tominaga
authors.forename: S
authors.initials: S
authors.lastname: Oda
authors.forename: A
authors.initials: A
authors.lastname: Kumasaka
authors.forename: R
authors.initials: R
authors.lastname: Tsugane
mesh_terms: D000328:Adult; D000368:Aged; D002544:Cerebral Infarction / Q000175:diagnosis*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis*; D011379:Prognosis; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000601:surgery*; D020301:Vasospasm, Intracranial / Q000175:diagnosis*