title: Comparison of cerebral blood flow pattern by transcranial Doppler in patients with diffuse and focal causes of brain death.
abstract: BACKGROUND
  This study aims to assess the cerebral vessels flow in brain death patients with different causes, including focal and diffuse lesions and comparison of flows according to the underlying causes.
  
  
  METHODS
  Two groups of 15 brain-dead patients one with focal and the other with diffuse brain lesions were compared according to their cerebral blood flow pattern 48 h passed brain death certification.
  
  
  RESULTS
  Bilateral absence of flow in middle cerebral artery (MCA) was found in 54.5% of brain-dead patients with diffuse lesion and 50.33% of those with focal lesions. Systolic spike pattern in MCA flow was found in 46.2% of patients with focal lesion and 16.65% of patients with diffuse lesion. Diastole-systole separation pattern in MCA was seen in 16.65% of patients with the diffuse lesions. This pattern in MCA was not seen in patients with the focal lesion group. In carotid arteries, we did not find the absence of flow in any cases. Thirty percent of all patients in both groups had a normal flow pattern (36.6% of patients with focal lesions and 23.3% of patients with diffuse lesion). Patients with focal lesion had 33.3% systolic spike pattern flow and had 23.35% diastole-systole separation flow pattern. In intra-cranial vessels, systolic spike pattern was more common among patients with focal lesions than patients with diffuse lesion, however, this difference was not statistically significant (46.2% of patients with focal lesion and 16.65% of patients with diffuse lesion) (P value = 0.244-0.09). Diastole-systole separation flow was more common in patients with diffuse lesions than those with the focal lesions although this could not reach the significant level as the previous pattern (20% of patients with diffuse lesion versus no case in patients with focal lesion) (P value = 0.181).
  
  
  CONCLUSIONS
  Absence of flow was the most common brain flow pattern in the focal and diffuse group lesions. There was no difference in flow pattern between the focal and diffuse brain lesions groups in brain-dead patients.
authors.affiliation: Department of Neurology, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Vakilian
authors.forename: Farhad
authors.initials: F
authors.lastname: Iranmanesh
keywords: Blood flow pattern; brain death; diffuse brain lesion; focal brain lesion