Microembolism versus hemodynamic impairment in rosary-like deep watershed infarcts: A combined positron emission tomography and transcranial doppler study

Ramez Reda Moustafa, Isabelle Momjian-Mayor, P. Simon Jones, Silvia Morbelli, Diana J. Day, Franklin I. Aigbirhio, Tim D. Fryer, Elizabeth A. Warburton, Jean Claude Baron

Research output: Contribution to journalArticlepeer-review


BACKGROUND AND PURPOSE-: Deep watershed infarcts are frequent in high-grade carotid disease and are thought to result from hemodynamic impairment, particularly when adopting a rosary-like pattern. However, a role for microembolism has also been suggested, though never directly tested. Here, we studied the relationships among microembolic signals (MES) on transcranial Doppler, rosary-like deep watershed infarcts on brain imaging, and cerebral hemodynamic compromise on positron emission tomography (PET), all in severe symptomatic carotid disease. We hypothesized that rosary-like infarcts would be significantly associated with worse hemodynamic status, independent of the presence of MES. METHODS-: Sixteen patients with ≥70% carotid disease ipsilateral to recent transient ischemic attack/minor stroke underwent magnetic resonance imaging including diffusion-weighted imaging, O-PET, and transcranial Doppler. Mean transit time, a specific marker for hemodynamic impairment, was obtained in the symptomatic and unaffected hemispheres. RESULTS-: Eleven of 16 patients had rosary-like infarcts (Rosary+) and 8 patients had MES. Mean transit time was significantly higher (P=0.008) in Rosary+ patients than in healthy controls (n=10), and prevalence of MES was not different between Rosary+ and Rosary- patients. Contrary to our hypothesis, however, the presence of MES within the Rosary+ subset was associated (P=0.03) with a better hemodynamic status than in their absence, with a significant (P=0.02) negative correlation between mean transit time and rate of MES/h. CONCLUSIONS-: Contrary to mainstream understanding, rosary-like infarcts were not independent of presence and rate of MES, suggesting that microembolism plays a role in their pathogenesis, probably in association with hemodynamic impairment. Pending confirmation in a larger sample, these findings have management implications for patients with carotid disease and rosary-like infarcts.

Original languageEnglish
Pages (from-to)3138-3143
Number of pages6
Issue number11
Publication statusPublished - Nov 2011


  • brain imaging
  • brain infarction
  • carotid stenosis
  • hemodynamics
  • PET
  • TCD
  • watershed infarcts

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Clinical Neurology
  • Advanced and Specialised Nursing


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