title: Distribution, Severity and Radiologic Features of Intracranial Stenosis in Asymptomatic Pakistanis.
abstract: BACKGROUND
  Intracranial atherosclerotic disease (ICAD) is the most common ischemic stroke subtype globally. It accounts for 30-50% of all ischemic strokes in Asians.
  
  
  OBJECTIVE
  The aim of the study is to report the frequency of asymptomatic ICAD and its associated Magnetic Resonance Imaging (MRI) findings.
  
  
  METHODS
  200 adult participants were recruited from the Radiology Departments of two major diagnostic centers in Karachi. Eligible participants were confirmed for the absence of stroke symptoms via the Questionnaire for Verifying Stroke Free Status (QVSFS). QVSFS negative subjects underwent MRI on a 1.5 Tesla scanner. Images were centrally reviewed on Di com Viewer 3.0 with electronic calipers to calculate the degree of ICAD.
  
  
  RESULTS
  Mean age of subjects was 37.1 years (S.D 15.1) with 50.5% men (n=101) and 49.5% women (n=99). Asymptomatic ICAD was found in 34.5% (n=69) subjects. Of the 3800 intracranial arteries studied, 2.2% (n=88) had biological disease. 20.5% (n=18) of these vessels had atherosclerotic irregularities, 43.2% (n=38) had mild stenos is, 11.4% (n=10) had moderate stenos is, 5.7% (n=5) had severe stenos is while 19.3% (n=17) were completely occluded. The posterior cerebral artery (42% of stenosed arteries, n=37) was most affected. 23.5% (n=47) of subjects had peri-ventricular lucencies, 10.5% (n=21) had brain atrophy while 3.5% (n=7) had silent brain infarcts. There was a significant association between asymptomatic ICAD and peri ventricular lucencies (PR 1.59; 95% CI 1.35-1.99).
  
  
  CONCLUSIONS
  Asymptomatic ICAD is common in young Pakistanis, with no gender predilection; it preferentially affects the posterior circulation. Silent infarcts are rare compared to peri ventricular lucencies and atrophy.
authors: Department of Neurology and Stroke Service, Aga Khan University, Pakistan.
authors: Ayeesha K
authors: AK
authors: Kamal
authors: Fogarty Cerebrovascular Research Fellow, Aga Khan University, Pakistan.
authors: Farzin
authors: F
authors: Majeed
authors: Department of Neurology, Dow University of Health Sciences, Pakistan.
authors: Muhammad S
authors: MS
authors: Ilyas
authors: Department of Radiology, Dow University of Health Sciences, Pakistan.
authors: Munawar
authors: M
authors: Hussain
authors: Department of Radiology, Dow University of Health Sciences, Pakistan.
authors: Kamran
authors: K
authors: Masood
authors: Department of Epidemiology and Biostatistics, Aga Khan University, Pakistan.
authors: Bilal
authors: B
authors: Ahmed
authors: Department of Medicine, Aga Khan University, Pakistan.
authors: Hasan
authors: H
authors: Rehman
authors: Department of Radiology, Aga Khan University, Pakistan.
authors: Zafar
authors: Z
authors: Sajjad
authors: Department of Neurology, University of Pennsylvania, USA.
authors: Scott E
authors: SE
authors: Kasner
keywords: Asymptomatic; Developing Countries; Epidemiology; Intracranial Stenosis; Prevention; Radiology; Stroke