http://doi.org/10.33698/NRF0312- Vinay Kumari, Meena Aggarwal, Achal Srivastava

Abstract : Risk factors for stroke are well established, but little is known about factors that may precipitate the acute event. The aim of this study was to identify triggers or precipitators related to the onset of stroke. A descriptive, retrospective cross sectional design was adopted for hospitalized stroke patients of Neurology wards, C.N Centre, AIIMS, New Delhi. 140 stroke patients/relatives were interviewed after the stroke event using a validated interview schedule. The results of the present study showed that hypertension was the most common risk factor reported by the study subjects. Two peak timings were found for the occurrence of stroke,i.e. 5 am to 9:59 am and between 3 pm to 7:59 pm. Unusual mental stress, time of the day, injury/illness within a week prior to the onset of stroke, sitting and standing posture and a change in posture seem to trigger or precipitate the onset of stroke. Incidence of stroke can be prevented through modification in life style (refraining from triggers), compliance to treatment and regular follow up.

Key words :Stroke, Triggers, Precipitators, Risk factors

Correspondence at : Vinay Kumari Lecturer MM College of Nursing Mullana, Ambala

Introduction:Stroke is one of the most common neurological disorders in clinical practice. It is the leading cause of adult disability and is the second commonest cause of death worldwide.1 More than two-thirds of the global burden of stroke is borne by developing countries, where the average age of patients with stroke is 15 years younger than in developed countries.2 It has been estimated that about 1,800 people die of stroke every day in India and stroke represented 1.2 % of the total deaths in the country, when all ages were included.3 A number of modifiable and non modifiable risk factors have been identified which may predispose to the occurrence of stroke. Non-modifiable risk factors include advanced age, male gender, non white race, and hereditary predisposition.4 The modifiable risk factors for stroke are hypertension, heart disease, diabetes, and cigarette smoking. Of all the risk factors that contribute to stroke, the most powerful is hypertension. Risk factors for stroke are well established, but little is known about factors that may precipitate the acute event. Established risk factors for ischemic and hemorrhagic stroke can only partially explain the individual risk for stroke and do not predict the timing and day of the acute event. Identification of patients with treatable risk factors for stroke is paramount and also the knowledge of potential triggers will be very helpful in prevention of onset of stroke.To the best of the investigator’s knowledge, in India, only one study is known till date related to squatting position as a triggering factor for the onset of stroke.5 Therefore, the present study has been designed to explore more triggers and to assess whether time, activity, posture, postural change, alcohol consumption, smoking, physical illness/ injury, medicine intake and extraordinary events such as unusual mental stress can trigger the onset of stroke.

AIM OF THE STUDY:To identify the triggers or precipitators related to the onset of stroke.

MATERIALS AND METHODS:The descriptive study was conducted using Quantitative, Survey approach. Stroke patients admitted in the neurology wards at the department of neurosciences center, AIIMS, New Delhi from July to December, 2007 who met the inclusion criteria were chosen as the sample using convenience sampling technique. The inclusion criterion for the study was : Age > 18 years, Stroke confirmed by CT scan , Stroke onset within 30 days preceding enrollment, patient / relative able to understand Hindi or English, patients and their relatives who are willing to participate. The patients with subarachnoid hemorrhage and who discharged / died before interview were not included in the study.A total of 140 stroke patients were selected as the sample. Based on the objectives of the study, self report method was found to be most feasible to collect the relevant data. Interview schedule was developed which was specifically designed for collection of data regarding stroke risk factors and triggers. The tool was developed after an extensive review of literature. Its content validity was established by five experts (two medical and three nursing experts) and reliability by test retest method (r=.992). Tool was translated into Hindi by experts in Hindi and back translation was done to English and desired corrections were made in the Hindi version. The tool consisted of four par ts i.e. Demographic data sheet: It has 13 items dealing with demographic characteristics i.e. name of the patient, age, gender, religion, dietary habits, educational status, and occupation, marital status, monthly family income, per capita income, total number of family members, type of family, residence. Clinical profile sheet: It consists of clinical parameters like type of stroke, onset of stroke, investigations done (hemoglobin, blood sugar, blood pressure). Risk factors assessment sheet : It includes questions on history of Transient ischemic attack (T.I.A), prior stroke, family history of stroke/ myocardial infarction, hyper tension, diabetes, hear t disease, myocardial infarction, hypercholestremia, smoking, alcoholism, tobacco chewing/ sniffing, illicit drug use. Triggers assessment sheet: It includes questions on time of onset of stroke, activity during onset of stroke, posture in which stroke occurred, change in posture just before the onset of stroke, history of smoking, alcohol drinking, medicine intake in 2 hrs prior to the onset of stroke, history of physical injury/illness immediately or a week prior to the onset of stroke, history of suffering with an unusual event immediately or within 24 hours preceding the stroke onset, history of unusual mental stress within last 4 weeks and beyond 24 hours prior to the onset of stroke.Ethical clearance was taken from Ethics committee. The subjects were enrolled based on the inclusion criteria. Informed consent was taken from the patients or relatives after giving explanation about the study. Data was collected by interviewing patients / relatives via a specifically designed interview schedule. Data was analyzed by calculating descriptive statistics such as frequency, percentage test using SPSS version-10.

RESULTS: Sample characteristics More number of the subjects i.e. 86 (61.4 %) had ischemic stroke as compared to hemorrhagic stroke 54 (38.6%). The males (70 %) outnumbered females (30 %) in total population of stroke subjects. Half of the subjects (51.4%) were in the age group of 51-70 years; 61.4 % were vegetarian by food habits; 75% were married. Majority of the subjects were literate (73.6 %) and one third (32.9 %) had a monthly family income between Rs.5001/- to 10000/-.

Clinical Parameters:Most of the subjects (83.6%) had normal hemoglobin (>10 gm/dl), 54% of the subjects had random blood sugar levels more than 140 mg/dl. Two third of the subjects (64.3%) had systolic blood pressure more than 140 mm Hg and 48.6 % of the subjects had diastolic blood pressure more than 90 mm Hg at the time of admission.Prevalence of known risk factors.The present study revealed that hypertension was the most prevalent risk factor reported by 52.9 % of the subjects and more than half (55.4 %) of them reported non compliance with anti hypertensive drugs. The other common risk factors identified in the present study were history of smoking (49.3%), alcoholism (37.9 %), diabetes (21.4%) , tobacco chewing (22.1%), previous history of stroke (20.7 %), and family history of stroke or myocardial infarction (20.7 %), history of heart disease (17.1%),  transient   ischemic    attack   (10.   7     %)     and   hypercholestremia (5.0%). (Fig 1) In the present study, nearly half i.e. 69 (49.3%) of the subjects had history of Fig 1: Prevalence of Known Risk Factors among stroke patients smoking and one third 50(35.7%) of them were current smokers. 53 (37.9 %) subjects had history of alcohol consumption and one fourth 36(25.7%) of them were current alcoholics. 31 (22.1%) subjects reported ever use of tobacco and 25 (17,8%) of them were current users.Potential triggers or precipitators related to the onset of stroke There were two peak timings for the occurrence of stroke. In 27.9 % of the subjects, first peak occurred between 0500 to 0959 hrs while in 25 % of the subjects, second peak was between 1500 to 1959 hrs. Only a few (7.1 %) of the strokes occurred between 0100-0459 hrs. (Fig.2)

Fig 2: Time of Onset of Stroke among Subjects Most of the subjects (70 %) were doing light activity at the onset of stroke, 8.6 % of subjects were sleeping and 10.7 % of subjects were resting in supine position. Three out of 140 subjects had onset of stroke during defecation (1 with ischemic and 2 with  hemorrhagic stroke).One third of the subjects were in standing (32.9 %) and almost same were in sitting posture (31.4 %) at the time of stroke. The least common posture was squatting posture found in 7.9% of the subjects. 37 (26.5 %) subjects reported change in their posture prior to stroke. Among them, 35 (25.0%) had slow change in posture while 2 had sudden changes. The 27 %subjects reported changed posture sitting to standing prior to stroke.History of injury or illness in one week prior to the onset of stroke was reported by 22.2 % subjects. Among them 38.7% had fever and 16.1% of the subjects had fever associated with other illness like cough, diarrhea or injury. Two hours prior to the onset of stroke 15.7 % of the subjects had smoked,2.1 % reported alcohol intake and 11.4 % of subjects had taken some medicine and majority of them had taken prescribed medicines.

Table -I : Unusual event experienced within 24 hours prior to onset of stroke by the Subjects   N=44*

Unsual events n (%)
Heavy Physical Activity 13 (30.0)
Clinical Mental Stress 29 (66.9)
Altered Rest / Sleep 7 (16.0)
Others 6 (14.0)

*Subjects have given more than one response

Some unusual event 24 hours prior to the onset of stroke was experienced by 44 (31.4 %) subjects i.e. heavy physical activity by 13(30%) subjects and unusual mental stress by 29(65.9 %) subjects. Among them the main cause of mental stress was due to conflicts with family/ friend in 13 (44.8 %) subjects and 13.6% of the subjects had unusual mental stress within 4 weeks and beyond 24 hours prior to the stroke onset.

DISCUSSION:The identification and modification of the traditional cerebrovascular risk factors is essential in the fight against stroke. In India, there hasn’t been much information available about what causes a stroke at a particular time of the day. Although adjustments in the traditional modifiable risk factors can reduce the risk of stroke substantially, the identification of new modifiable risk factors or triggers is essential to provide and emphasize on different treatment strategies for prevention of stroke. Early detection and modification of lifestyle can reduce the incidence and impact of this disease.In the present study, out of total (140) study subjects, 86 had ischemic and 54 had hemorrhagic stroke. Mean age of the subjects in total population was 58.85 years and ranging between 22-95 years.Male to female ratio in the present study was 98: 42 which is similar with the earlier study done 5 in which the male to female ratio was 69: 31.The present study revealed that hypertension and non compliance with anti hypertensive drugs was the risk factor reported by more than half of the subjects. Klungel et (1999)6 also reported that about a quar ter of all incident strokes among hypertensive were due to noncompliance of hyper tensive treatment. On admission,majority (64.3 %) of the subjects had high systolic blood pressure (more than 140 mm Hg) and 48.6 % had diastolic blood pressure more than 90 mm Hg. The findings of present study revealed that 40.7 % of the hemorrhagic stroke subjects were illiterate that could be the reason for poor compliance with antihypertensive drugs which eventually led to hemorrhagic stroke. Hsiang et al 7 also observed that only 20% of the hypertensive hemorrhagic stroke subjects had compliance with antihypertensive medication.The other common risk factors identified in the present study were history of smoking (49.3%), alcoholism (37.9 %),tobacco chewing (22.1%), diabetes (21.4 %), previous history of stroke (20.7 %), and family history of stroke or myocardial infarction (20.7 %), history of heart disease (17.1%), transient ischemic attack (10. 7 %) and hypercholestremia (5.0%). The risk factors identified in Indian population are hypertension, diabetes mellitus, smoking, tobacco chewing, coronary artery disease, rheumatic heart disease, hyperlipidemia, and low hemoglobin levels.8 ,9 ,10 In the present study, there were two peak timings for the occurrence of stroke. In 27.9 % of the subjects, first peak occurred between 0500 to 0959 hrs while in 25 % of the subjects, second peak was between 1500 to 1959 hrs. Only a few (7.1 %) of the strokes occurred between 0100-0459 hrs. Other study done in India (2002)5 found 52 % of strokes occurred between 5-9 am. Stergiou GS et al (2002) 11  observed one evening and one morning peak in stroke onset as well. Increase in morning blood pressure may be considered as a causative factor for peak occurrence of stroke in morning,12 ,13 ,14 . A morning increase in platelet agreeability, blood viscosity and haematocrit has also been suggested as triggering factors leading to cerebral and myocardial infarction.15 ,16 Only 2.1% of patients were engaged in heavy activity at the time of onset of stroke, similar kind of findings were reported by Chakrabarti et al (2002) 5 in 1 % of study subjects.Standing (32.9 %) and sitting posture (31.4 %) was observed as the most frequent posture in the present study while Chakrabarti et al (2002 )5 observed only 24 % strokes in sitting posture and 17 % in standing posture. Squatting posture at the onset of stroke was 7.9% in the present study, whereas Chakrabarti et al.5 found squatting in 36% of subjects in their study.26.5 % of subjects had change in posture prior to stroke, 25 % of them had slow change in posture and 1.4 % had sudden change whereas Koton et al. (2004)17 found sudden changes in body posture as the most important potential triggers for ischemic stroke. 31.4 % of the subjects reported experience of some extraordinary/ unusual event within 24 hours prior to the onset of stroke and unusual mental stress was the most common unusual event reported by majority (65.9 %) of the them. In the present study, 5/54 subjects with hemorrhagic stroke were engaged in heavy physical activity within 24 hours prior to the onset of stroke. In other study acute strenuous physical exertion was significantly associated with the onset of ICH.17 Tofler et al (1990)18 reported emotional upset and moderate physical activity as the most common triggers, followed by lack of sleep and overeating. A case-crossover study on ischemic stroke found an association with anger in the 2 hours preceding symptoms and also exposure to negative emotions during the hazard period was associated with a high odds ratio for ischemic stroke.18  Ghiadoni L (2000)19 suggests that brief episodes of mental stress, similar to fthose encountered in everyday life, may cause transient endothelial dysfunction.Unusual mental stress, time of the day, injury/illness within a week prior to the onset of stroke, sitting and standing posture and a change in posture seem to trigger or precipitate the onset of stroke. Incidence of stroke can be prevented through modification in life style (refraining from triggers), compliance to treatment and regular follow up.It is important for nurses to be aware of triggers for stroke as once triggers stroke are identified, incidence of stroke due to the triggering factors in an individual can be prevented through modification in life style, compliance to treatment and regular follow up. Important role of nurses is to provide health education and counseling on lifestyle modification and refrain from triggers to stroke patients for prevention of future recurrence. Stroke Performa need to be developed and incorporated in nurses record exploring the triggers and risk factors associated with stroke. Case cross over studies on the exploration of triggers can be done on a larger sample. Future studies on exploration of other triggers can be done on a larger sample. Nurse administrators should make provision of assessment sheet to record the circumstances around the onset of stroke by the nurses working with stroke patients. Nursing personnel at community level should remain in constant contact with hypertensive or “stroke prone” (TIA with hypertension) subjects to ensure regular intake of medication

REFERENCES

1.Bonita R, Mendis S, Truelsen T. The global stroke initiative. Lancet Neurol 2004; 3:391–3.

  1. Truelsen T, Bonita R, Jamrozik Surveillance of stroke: a global perspective.Int J Epidemiol 2001; 30:S11–16.
  2. Anand K, Chowdhury D, Singh KB, Pandav CS, Kapoor SK. Estimation of mortality and morbidity due to strokes in  Neuroepidemiology 2001; 20: 208-211.
  3. Ingall J. , Preventing ischemic stroke current approaches to primary and secondary prevention. Postgrad Med 107 (2000) (6):pp. 34– 50
  4. Chakrabarti SD, Ganguly R, Chatterjee SK, Chakravarty Is squatting a triggering factor for stroke in Indians? Acta Neurol Scand. 2002;105:124-27.
  5. Klungel OH, Stricker BHC, Paes AH, Seidell JC, Bakker A, Vokó Z, Breteler MMB, de Boer Excess stroke among hypertensive men and women attributable to undertreatment of hypertension. Stroke 1999;30:1312–1318.Hsiang JN, Zhu XL, Wong LK, Kay R, Poon Putaminal and thalamic hemorrhage in ethnic
  6. Dalal Strokes in elderly: prevalence, risk factors & strategies of prevention. Indian J Med Res.1997 ;Oct;106:325-3.
  7. Kaul S, Sunitha P, Suvarna A, Meena AK, Uma M, Reddy J Subtypes of ischemic stroke in metropolitian city of south India (One year data from a hospital based stroke registry ).Neuro India 2002 ; 50 (suppl 1): s8-s14.
  8. Mac Mohan S, Peto R,Cutler J, Collins R, Sorlie P, Neaton Epidemiology blood pressure, stroke and coronary heart diseases part 1 &2. Lancet 1990; 335: 765-839.
  9. Stergiou GS, Vemmos KN, Pliarchopoulou KM, Synetos AG, Roussias LG, Mountokalakis TD. Parallel morning and evening surge in stroke onset, blood pressure, and physical Stroke 2002; Jun33(6):1480-86.
  10. Muller Circadian variation in cardiovascular events. Am J Hypertens 1999; 12: 35S–42S.
  11. Elliott WJ. Circadian variation in blood Implications for the elderly patient. AmJ Hypertens 1999; 12:43S–49S.
  12. Johnstone MT, Mittleman M, Tofler G et The pathophysiology of the onset of morning cardiovascular events. Am J Hyper tens 1996;9:22–8.
  13. Aronson Impaired modulation of circadian rhythms in patients with diabetes mellitus: a risk factor for cardiac thrombotic events? Chronobiol Int 2001; 18:109–21.
  14. Tofler GH, Brezenski D, Schafer AL et Concurrent morning increase in platelet aggregability and the risk of myocardial infarction and sudden cardiac death. N Engl J Med 1987;316:1514–8.
  15. Koton S, Tanne D, Green S. Triggering risk factors for ischemic stroke.A case cross over study.Neurology 2004;63:2006-10.
  16. Tofler GH, Stone PH, Maclure M, Edelman E, Davis VG, Robertson T, Antman EM, Muller Analysis of possible triggers of acute myocardial infarction (the MILIS study). Am J Cardiol 1990;66:22–7.
  17. Ghiadoni L, Donald AE, Cropley M et Mental stress induces transient endothelial dysfunction in humans. Circulation 2000; 102:2473-2478.