title: Intracranial dermoid cyst rupture-related brain ischemia: Case report and hemodynamic study.
abstract: BACKGROUND
  Spontaneous rupture of intracranial dermoid cyst is a rare but serious clinical event that can result in cerebral ischemia. Cerebral vasospasm and vasculitis are considered as potential mechanisms of dermoid cyst rupture-related cerebral ischemia. However, the hemodynamic mechanisms between cerebral ischemia and dermoid cyst rupture are not well known.
  
  
  METHODS
  A 55-year-old, right-handed man was admitted to our hospital with sudden receptive aphasia and right-sided hypoalgesia. Brain magnetic resonance imaging (MRI) revealed a ruptured dermoid cyst and watershed infarcts in the left hemisphere. Then brain magnetic resonance angiography disclosed mild stenosis in the left middle cerebral artery (MCA), and further high-resolution MRI demonstrated it was caused by an unstable atherosclerosis plaque. Transcranial Doppler of the patient showed a decreasing tendency of peak systolic velocity (PSV) of the left MCA at different time points after the stroke (from 290cm/s at day 6 to 120cm/s at day 30), indicating a transient vasospasm. However, the time course of dynamic cerebral autoregulation (dCA) seemed different from the PSV. The patient's dCA reached its lowest point at day 8 and was restored at day 10. The time course of dCA indicated a "called procedure" of a cerebrovascular regulating function to deal with the stimulation in subarachnoid space.
  
  
  METHODS
  A dermoid cyst rupture-related cerebral infarction was diagnosed in this patient.
  
  
  METHODS
  Aspirin (100 mg/d) and atorvastatin (20 mg/d) were given to the patient. A neurosurgical operation was strongly recommended to minimize the risk of further injury of the ruptured dermoid cyst; however, the patient refused the recommended treatment.
  
  
  RESULTS
  The neurological deficit of the patient was significantly improved on 30 days follow-up.
  
  
  CONCLUSIONS
  We found that the spread of cyst contents through the subarachnoid and/or ventricular system can induce a vasospasm. Then, dCA was "called" to deal with the stimulation in the subarachnoid space. Compromised dCA seems to be one of the compensatory of cerebral vasospasm after a dermoid cyst rupture.
authors.affiliation: Department of Neurology, Stroke Center, the First Hospital of Jilin University, Chang Chun, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Jin
authors.forename: Zhen-Ni
authors.initials: ZN
authors.lastname: Guo
authors.forename: Yun
authors.initials: Y
authors.lastname: Luo
authors.forename: Ren
authors.initials: R
authors.lastname: Zhao
authors.forename: Ming-Shuo
authors.initials: MS
authors.lastname: Sun
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging; D002545:Brain Ischemia / Q000209:etiology* / Q000503:physiopathology; D001932:Brain Neoplasms / Q000150:complications* / Q000503:physiopathology; D003884:Dermoid Cyst / Q000150:complications* / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D012422:Rupture, Spontaneous / Q000150:complications / Q000503:physiopathology; D020301:Vasospasm, Intracranial / Q000209:etiology