Clinico-epidemiological study of acute ischemic stroke in a tertiary hospital of northeastern state of India

Stroke or cerebro-vascular accident is a leading cause of mortality and morbidity throughout the world including both developed and developing countries. In country like India, the cases are also increasing with gradual increase in obesity, diabetes mellitus, hyperlipidemia, hypertension and some other cardiac problem. The incidence of stroke increases with age and the number of stroke is projected to increase as the elderly population grows. Stroke is a medical emergency and need urgent diagnosis and treatment1.


Introduction
Stroke or cerebro-vascular accident is a leading cause of mortality and morbidity throughout the world including both developed and developing countries. In country like India, the cases are also increasing with gradual increase in obesity, diabetes mellitus, hyperlipidemia, hypertension and some other cardiac problem. The incidence of stroke increases with age and the number of stroke is projected to increase as the elderly population grows. Stroke is a medical emergency and need urgent diagnosis and treatment 1 .
Stroke is defined by the abrupt onset of a neurological deficit that is attributable to a focal vascular cause. The clinical manifestations of stroke are highly variable because of the complex anatomy of the brain and its vasculature. Stroke may be broadly classified into ischemic and hemorrhagic stroke. Ischemic stroke occurs due to loss of blood supply to part of brain initiating ischemic cascade due to free radical production and damage to endothelial lining. At present, diagnosis of stroke is mostly based on CT scan (Computer Tomography) or Magnetic Resonance Imaging 1 . Studies had been conducted on the epidemiology and risk factors of acute stroke in various parts of world including India. The present study has been conducted in a tertiary care hospital of northeastern region of India with a primary objective to view the clinical presentation and epidemiology of acute ischemic stroke in this population of northeastern region of India.

Materials and Method
This crossectional study had been conducted in Department of Medicine in collaboration with the Department of Emergency Medicine and Radiodiagnosis, RIMS Imphal, India from March 2010 to March 2012. A total of 100 acute ischemic stroke patients (clinically and radiologically confirmed) admitted in OPD/Ward/Emergency had been taken irrespective of sex and age in the present study. Exclusion criteria were patients dying before recording the information, patients refusing to give consent to take part under the study.

Sample size:
A total of 100 acute ischemic stroke patients irrespective of age and sex.

Study tool and data collection:
A pre designed semi-structural proforma, designed for the purpose was used as a study tool. A proforma of all the acute ischemic stroke patients had been maintained where in a brief clinical information including particulars of the subjects, chief complaints, family, menstrual, personal, dietary history, past history were taken. Proper general physical examination and systemic examination were also done and recorded in the proforma. The acute ischemic stroke patients were subjected to plane CT scan brain in the Department of Radio-diagnosis, RIMS by using CT scan model Philips Brilliance 64 slice CT with Advanced Brilliance 3D Workstation to confirm the diagnosis and also for localizing the site of lesion.

Statistical analysis:
The collected data are processed through simple statistical method like percentage.

Ethical issue:
This study was conducted only after getting approval from Institutional Ethical Committee, RIMS, Imphal. Informed consent from the participating individual was also obtained. Confidentiality was maintained by masking the identity and identifiers of the participants.

Results
The present study is based on the primary data of 100 acute ischemic stroke patients irrespective of sex and age. In the present study, majority of acute ischemic stroke patients were male( 57%) whereas maximum number of acute ischemic stroke patients(56%) was in age group (50-75) years followed by 25-50 age group(30%).Majority of the acute ischemic stroke patients were Hindus (53%) and married(83%) as shown in table 1. Analysis of the risk factors of acute ischemic stroke revealed that majority of acute stroke patients were hypertensive(68%) and other risk factors also include smoking(60%), non-veg diet(76%), diabetes mellitus(37%) ( Table-2).

Discussion
In the present study, the role of non-modifiable risk factors like age and sex in acute ischemic stroke were studied and a small male predominance among stroke patients has been found, which is supported by other studies 2,3,4 . The higher male preponderance in this study may be due to the fact, that women are neglected part of the society and they are not brought to hospital, if not otherwise seriously ill. Beside, smoking which is a risk factor for acute ischemic stroke is more common in men. In this study it is seen that in ischemic stroke patients majority of the sufferers were in the 50-75 age group followed by age group > 75 yrs. So it clear from this study that acute ischemic stroke occurs more commonly in elderly. In the present study, majority of acute ischemic stroke patients were Hindus(53%) and married(83%), which may be because of regional socio-cultural variation.
In this study hypertension(68%) emerges as the most important risk factor in acute ischemic stroke. The result correlates with that of other studies where hypertension was found to be the most important risk factor 3,5,6 . Smoking(60%) appears as second important risk factor of ischemia stroke in this study, which correlates with Donnan et al 7 , who found smoking as a strong risk factor for SAH and cerebral infarction. John W Cole et al 8 demonstrated that cigarette smoking may modulate stroke risk through a gene-environment interaction. V. M Bhat 9 and Md Jalal Uddin et al 10 also suggested a strong relationship between cigarette smoking and causation of acute ischemic stroke. In the present study, non-vegetarian constitutes maximum of the acute ischemic stroke patients (76%). Studies done by Joshipura et al 11 and SP Josephson et al 12 shows the protective response of fruits and vegetables in causation of ischemic stroke. Diabetes mellitus has long been recognized as a risk factor for vascular disease and it doubles the risk of stroke compared with non-diabetics 13 . In this study diabetes(37%) appears to be associated with stroke, which correlates with the Framingham study 14 .
In the current study, commonest neurological deficit in acute ischemic stroke was hemiparesis(80%), followed by dysarthria (60%), motor dysphasia (59%). However, various grades of weakness were not brought into consideration in this study. This result correlates with few studies where hemiplegia was also found to be the commonest presentation 5,14,15 . In this study, impaired consciousness (54%) was found in many cases of acute ischemic stroke, which also correlates with other studies 2,5 . Majority (52%) of the acute stroke patients were having grade-2 Glasgow Coma Scale(GCS) at presentation. Similar finding has been observed by Siddique AN et al 5 . In this study left hemispheric lesion of brain constitutes majority (56%) of the acute ischemic stroke patients. H Ito et al 16 in their study on the side of lesion in stroke also observed similar results. Cerebral cortex (59%) was the most site of lesion in the acute stroke patients, which is supported by the findings of Siddique AN 5 .

Conclusion
Acute ischemic stroke, being one of the most common cerebrovascular diseases, has drawn attention of researchers all over the world. For better understanding of the pathogenesis and therapeutics of acute ischemic stroke, clinicoepidemiological aspects and risk factors associated with ischemic stroke remains important as ever. The burden of this disabling disease can be prevented by targeting the various risk factors of the acute ischemic stroke.