Maria Khan

The burden of stroke and transient ischemic attack in Pakistan: a community-based prevalence study

BackgroundThe burden of cerebrovascular disease in developing countries is rising sharply. The prevalence of established risk factors of stroke is exceptionally high in Pakistan. However, there is limited data on the burden of stroke and transient ischemic attack (TIA) in South Asia. We report the first such study conducted in an urban slum of Karachi, Pakistan.MethodsIndividuals 35 years of age or older were invited for participation in this investigation through simple random sampling. A structured face-to-face interview was conducted using a pre-tested stroke symptom questionnaire in each participant to screen for past stroke or TIA followed by neurological examination of suspected cases. Anthropometric measurements and random blood glucose levels were recorded. Multivariable logistic regression was used to determine the association of vascular risk factors with prevalence of stroke.ResultsFive hundred and forty five individuals (49.4% females) participated in the study with a response rate of 90.8%. One hundred and four individuals (19.1%) were observed to have a prior stroke while TIA was found in 53 individuals (9.7%). Overall, 119 individuals (21.8% with 66.4% females) had stroke and/or TIA. Female gender, old age, raised random blood glucose level and use of chewable tobacco were significantly associated with the prevalence of cerebrovascular disease.ConclusionThis is the first study demonstrating an alarmingly high life-time prevalence of cerebrovascular disease in Pakistan. Individual and public health interventions in Pakistan to increase awareness about stroke, its prevention and therapy are warranted.

Stroke Radiology and Distinguishing Characteristics of Intracranial Atherosclerotic Disease in Native South Asian Pakistanis

Background There are no descriptions of stroke mechanisms from intracranial atherosclerotic disease in native South Asian Pakistanis. Methods Men and women aged ≥18 years with acute stroke presenting to four tertiary care hospitals in Karachi, Pakistan were screened using magnetic resonance angiography/transcranial Doppler scans. Trial of ORG 10172 in Acute Stroke Treatment criteria were applied to identify strokes from intracranial atherosclerotic disease. Results We studied 245 patients with acute stroke due to intracranial atherosclerotic disease. Two hundred thirty scans were reviewed. Also, 206/230 (89·0%) showed acute ischaemia. The most frequent presentation was with cortically based strokes in 42·2% (87/206) followed by border-zone infarcts (52/206, 25·2%). Increasing degrees of stenosis correlated with the development of both cortical and border-zone strokes (P = 0·002). Important associated findings were frequent atrophy (166/230, 72·2%), silent brain infarcts (66/230, 28%) and a marked lack of severe leukoaraiosis identified in only 68/230 (29·6%). A total of 1870 arteries were studied individually. Middle cerebral artery was the symptomatic stroke vessel in half, presenting with complete occlusion in 66%. Evidence of biological disease, symptomatic or asymptomatic was identified in 753 (40·2%) vessels of which 543 (72%) were significantly (>50%) stenosed at presentation. Conclusion Intracranial atherosclerotic disease is a diffuse process in Pakistani south Asians, with involvement of multiple vessels in addition to the symptomatic vessel. The middle cerebral artery is the most frequent symptomatic vessel presenting with cortical embolic infarcts. There is a relative lack of leukoaraiosis. Concomitant atrophy, silent brain infarcts and recent ischaemia in the symptomatic territory are all frequently associated findings.

Mycobacterium tuberculosis infection of a native polycystic kidney following renal transplantation

M.A. Rabbani, B. Ahmed, M.A. Khan. Mycobacterium tuberculosis infection of a native polycystic kidney following renal transplantation.
Transpl Infect Dis 2011: 13: 44–46. All rights reserved

Controversies of treatment modalities for cerebral venous thrombosis.

Cerebral vein thrombosis has been well recognized for nearly two centuries. However, therapeutic options for the condition are limited due to lack of large randomized trials. The various modalities reportedly used include antiplatelets, anticoagulation, fibrinolysis, and mechanical thrombectomy. Of these, antiplatelets are the least studied, and there are only anecdotal reports of aspirin use. Anticoagulation is the most widely used and accepted modality with favorable outcomes documented in two randomized controlled trials. Various fibrinolytic agents have also been tried. Local infusions have shown more promise compared to systemic agents. Similarly, mechanical thrombectomy has been used to augment the effects of chemical thrombolysis. However, in the absence of randomized controlled trials; there is no concrete evidence of the safety and efficacy of either of these modalities. Limited study series disclosed that decompression surgery in malignant CVT can be life saving and provides good neurological outcome in some cases. Conclusion. Overall therapeutics for CVT need larger randomized controlled trials. Anticoagulaion with heparin is the only modality with a reasonable evidence to support its use in CVT. Endovascular thrombolysis and mechanical thrombectomy are reserved for selected cases who fail anticoagulation and decompression surgery for malignant CVT with impending herniation.

Frequency and Determinants of Intracranial Atherosclerotic Stroke in Urban Pakistan

BACKGROUND Intracranial atherosclerosis (ICAD) is a frequent underlying mechanism of ischemic stroke. There is little direct evidence on its frequency and determinants from regions of high prevalence. This study explores the conventional and socioeconomic risk factors of ICAD in a South Asian population. METHODS The Karachi Intracranial Stenosis Study is a case-control study of 313 cases of ischemic stroke secondary to ICAD and 331 controls enrolled from 4 major hospitals in Karachi, Pakistan. Stroke subtype was verified by a vascular neurologist using the Trial of Org 10172 in Acute Stroke Treatment classification. Relationships of conventional and socioeconomic risk factors with ICAD-related strokes are reported by calculating odds ratios (ORs) and their 95% confidence intervals (CIs). RESULTS ICAD was the cause of stroke in 81.1% cases with large-artery atherosclerosis and 19.5% of all stroke events. Along with risk factors like history of hypertension (OR, 3.33; CI, 2.31-4.78), history of diabetes (OR, 2.29; CI, 1.56-3.35), use of tobacco (OR, 1.49; CI, 1.03-2.16), waist-to-hip ratio (OR, 1.58; CI, 1.04-2.41), and family history of stroke (OR, 1.89; CI, 1.21-2.95), other significant social determinants of ICAD strokes were monthly income (OR, 1.59; CI, 1.01-2.51), unemployment (OR, 2.15; CI, 1.21-3.83), and chronic stress (OR, 3.67; CI, 2.13-6.34). These social determinants were independent predictors of the risk of ICAD, in addition to those described in other world populations. CONCLUSIONS ICAD accounted for one fifth of all strokes making it the most common ischemic stroke mechanism. In addition to aggressive risk factor control, data also indicated broader holistic efforts on ameliorating inequity, unemployment, and stress reduction to reduce stroke because of ICAD.

Neuroimaging of Intracranial Atherosclerotic Disease

Ischemic stroke is now universally accepted as a heterogeneous disease. The need to properly classify stroke subtypes is increasingly driven by the realization that different mechanisms may require different treatments. Also the risk of recurrent vascular events differs among various ischemic stroke subtypes. Intracranial atherosclerotic disease (ICAD) is fast emerging as the predominant mechanism of ischemic stroke in the world and particularly in patients of Asian origin (Kim et al, 2006 and Sacco et al, 1995). Also, ICAD is reported to have the highest risk of recurrent ischemic cerebrovascular events being quoted between 25-30% in two years (Wong et al, 2003 and Mazighi et al, 2006).