Stroke subtypes in Sri Lanka--a hospital based study

Ischemic Stroke Subtypes: Socio-demographic Factors, Risk Factors, and Outcomes in Southern Sri Lanka

Background

Stroke is a heterogeneous, catastrophic disease. A comprehensive clinical analysis of ischemic stroke (IS) risk factors and outcomes is crucial for optimum management in resource-poor settings.

Methods

A prospective cross-sectional study of acute cerebrovascular disease (ACVD) involving 592 patients was conducted in a tertiary care center in Sri Lanka from November 2018 to May 2019. We aimed to describe the ACVD subtypes and the relationship of IS subtypes and subtype-categories (as defined by the Oxfordshire Community Stroke Project clinical classification) with risk factors, severity, and outcome.

Results

The majority (63.3%) had IS. Partial anterior circulation syndromes (PACS), total anterior circulation syndrome (TACS), posterior circulation syndromes (POCS), and lacunar syndromes (LACS) accounted for 102 (29.7%), 58 (16.9%), 88 (25.7%) and 95 (27.7%) of the cases, respectively. The most common PACS sub-category was higher-cerebral-dysfunction-with-homonymous-hemianopia (HCD+HH,39 cases;38.2%). Cerebellar-signs-without-long-tract-signs (CS-LTS) sub-category constituted the highest among POCS (47 cases; 53.4%). The leading sub-category within LACS was pure-motor (PM) strokes (43 cases; 45.3%).Patients aged ≥50 years (adjusted-OR [AOR]2.439; 95%CI,1.163-5.116;P=.018), IHD(AOR 2.520; 95%CI,1.347-4.713; P=.004) and BMI>23kg/m²(AOR 2.607; 95% CI,1.420-4.784; P=.002) were 2.5 times more likely to associate with TACS. Patients with a history of TIA (AOR 1.910; 95%CI,1.036-3.524; P=.038) and arrhythmias (AOR 5.933; 95%CI,3.294-10.684; P<.001) were 1.9 and 5.9 times more likely to be associated with POCS respectively. Those with hypertension were 2.3 times more likely to associate with LACS (AOR 2.233; 95%CI,1.270-3.926; P=.005).NIHSS(P<.001), mRS on admission (P=.001) and in 3 months (P<.001), deaths during hospital stay (P=.003) and within 28 days (P<.001) had a stronger relationship with individual stroke subtypes.

Conclusion

The comparative risk of different IS subtypes depends on different risk factors. The findings of this study demonstrate that sub-categories within each stroke subtype may behave independently with regard to risk factors and outcomes, thus warranting the need for individual assessment.

Stroke Epidemiology in South, East, and South-East Asia: A Review

Asia, which holds 60% of the world’s population, comprises some developing countries which are in economic transition. This paper reviews the epidemiology of stroke in South, East and South-East Asia. Data on the epidemiology of stroke in South, East, and South-East Asia were derived from the Global Burden of Disease study (mortality, disability-adjusted life-years [DALYs] lost because of stroke), World Health Organization (vascular risk factors in the community), and publications in PubMed (incidence, prevalence, subtypes, vascular risk factors among hospitalized stroke patients). Age- and sex-standardized mortality is the lowest in Japan, and highest in Mongolia. Community-based incidence data of only a few countries are available, with the lowest rates being observed in Malaysia, and the highest in Japan and Taiwan. The availability of prevalence data is higher than incidence data, but different study methods were used for case-finding, with different age bands. For DALYs, Japan has the lowest rates, and Mongolia the highest. For community, a high prevalence of hypertension is seen in Mongolia and Pakistan; diabetes mellitus in Papua New Guinea, Pakistan, and Mongolia; hypercholesterolemia in Japan, Singapore, and Brunei; inactivity in Malaysia; obesity in Brunei, Papua New Guinea, and Mongolia; tobacco smoking in Indonesia. Hypertension is the most frequent risk factor, followed by diabetes mellitus and smoking. Ischemic stroke occurs more frequently than hemorrhagic stroke, and subarachnoid hemorrhages are uncommon. There are variations in the stroke epidemiology between countries in South, East, and South-East Asia. Further research on stroke burden is required.

Cerebrovascular disease in South Asia - Part I: A burning problem

Stroke is a non-communicable disease of increasing socioeconomic importance in ageing populations. According to the World Health Organization, stroke was the second most common cause of worldwide mortality. In South Asian countries demographic changes, urbanization and increased exposure to major stroke risk factors will fuel the stroke burden in the future. The prevalence of stroke in India is 44–843/100,000 (from community-based studies), 500–2000/100,000 in Bangladesh, 218/100,000 in Pakistan and 1000/100,000 in Sri Lanka and community-based prevalence studies in these countries are still lacking. There are no data on stroke prevalence from Nepal. Incidence studies are still less and an Indian study reported an incidence of 145/100,000. Incidence studies from other South Asian countries are lacking. This review attempts to give an overview of the evidence so far on the burden of stroke in this part of the globe.

Stroke in Asia

The epidemic of cardiovascular disease across most of Asia is at a different stage from that in the West; the incidence and prevalence of stroke are increasing steadily, associated with nutritional changes and aging of the population. Epidemiologic data, crucial in combating stroke, have been relatively sparse in Asian populations, but a few international collaborative studies on stroke have been in progress for several years. Through these, we now know that ischemic stroke is actually the most frequent type of cerebrovascular accident in Asia, although hemorrhagic stroke remains more common in Asia than in the West. Also, the percentage of ischemic stroke attributable to intracranial vascular disease is much higher than in the West. In Japan and a few other countries, stroke rates are declining; however, increasing rates in most other countries make primary prevention of critical importance in minimizing the severe impact of this epidemic in Asia.

Transcultural expression of subcortical vascular disease

BACKGROUND

Many transcultural issues pertaining to subcortical vascular disease remain unanswered, and there is a relative paucity of research on stroke and dementia in non-Western societies.

OBJECTIVE

To describe variations in the epidemiology of stroke and dementia, the recognition of dementia as an entity across cultures, the cultural specificity of screening tools and assessment instruments, and cultural influences on the management of stroke and dementia.

RESULTS

Several studies have pointed out differences in the subtypes and outcomes from stroke across different world regions. Notably, non-Western populations may have a higher rate of hemorrhage, whilst in ischemic stroke subcortical vascular disease is predominant. A low prevalence of dementia has been demonstrated in many studies of non-Western populations. Factors proposed to account for this include protective family attitudes, a lower frequency of ApoE4 and the high mortality of non-Western dementia subjects, which may mask a high age-specific incidence rate. Other medical factors such as training, diagnostic skills, the availability of investigations and healthcare provision may also play a role, as would patient specific cultural attitudes towards ageing and mental health, together with differences in language, social customs and literacy. It has been suggested that there is a major difference between Western and Asian nations in the ratio of vascular dementia to Alzheimer disease. However, few epidemiological field studies have utilized neuroimaging and the reported rates for particular diagnoses should be interpreted cautiously. A recent population study in Japan, which utilized screening by neuropsychologists and CT scanning, showed that vascular dementia accounted for nearly half the cases of dementia. Subcortical vascular disease accounts for the majority of patients with vascular dementia (VaD).

CONCLUSIONS

With the rapid demographic changes taking place in non-Western countries, non-communicable diseases such as dementia and stroke will increasingly come to dominate disease burden. More studies are required to prevent and treat these diseases.