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Stroke in the young in sicily: Prevalence and clinical features
Stroke in the Young in Sicily: Prevalence and Clinical Features Francesco Patti, MD, Gaetano Failla, MD, Arturo Reggio, MD, Giuseppe Salemi, MD, Letterio Morgante, MD, Francesco Grigoletto, MD, Giovanni Savettieri, MD, and Raul Di Perri, MD
Few epidemiological reports focus on the prevalence of stroke in the young population. As part of a neuroepidemiological survey on the total population of three Sicilian municipalities, we assessed the prevalence of stroke in the young, describing the clinical features of each patient. We screened 14,832 subjects younger than 40 years with a door-to-door method and a two-phase study design. Phase 1 consisted of a questionnaire and a brief neurological examination; phase 2 was an extensive evaluation performed by a neurologist. On the prevalence day (November 1, 1987), we ascertained six cases of stroke (prevalence rate, 40.5/100,000). Three were hemorrhagic, one ischemic, and two of uncertain type. Recovery was good in five patients; only one needed aids for walking. Stroke is uncommon in the young, but its prevalence rapidly increases in an age-related fashion. Hemorrhagic lesions are probably more represented in this age-group. Survivors tend to show good motor recovery. Key Words: Epidemiology--Stroke--u
Despite a slow, progressive decrease, cerebrovascular diseases still represent the third most c o m m o n cause of mortality in most industrialized countries I and the main cause of chronic disability in the elderly; nonetheless, acute cerebrovascular events m a y occur in younger persons as w e l l accounting for approximately 3% to 5% of all strokes. 2-4 Even though m a n y epidemiological studies have addressed incidence, risk factors, and outcome of stroke at all ages 5-s or in the y o u n g o n l y 9-12 in well-defined populations, few authors have investigated the prevalence of stroke with a door-to-door methodology. 13-17 Only a comprehensive investigation with a door-todoor methodology on a sufficiently large population m a y yield reliable data about prevalence of an u n c o m m o n neurological disease such as stroke in childhood and young adulthood; similar data could be suitable for comparisons among different populations. From the Departments of Neurology, University of Catania, University of Palermo, University of Messina, University of Naples; and the Department of Statistical Sciences,University of Padua, Italy. Received July 21, 1997; accepted October 28, 1997. Address reprint requests to Arturo Reggio, Istituto di Scienze Neurologiche, Po]iclinico Universitario, viale Andrea Doria, 6-95125 Catania, Italy. Copyright 9 1998by National Stroke Association 1052-3057/98 / 0703-000653.00/ 0
196
The current report is part of a door-to-door epidemiological investigation on the total population of three Sicilian municipalities, designed to detect the prevalence and clinical features of some common neurological diseases. TM The aim of this report is to provide data on the morbidity of stroke in younger patients and to describe the clinical findings in these patients.
Methods
Population Description and General Study Design The study population consisted of all subjects younger than 40 years residing in the Sicilian municipalities of Riposto (Catania province), Santa Teresa di Riva (Messina province), and Terrasini (Palermo province) as of November 1, 1987. Resident lists maintained in each municipality served as a survey frame along with data from the 1981 Census of the Italian population. We ascertained cases of stroke through a door-to-door survey with a two-phase design (Fig 1). During phase 1, a screening instrument was administered to eligible subjects. In phase 2, all subjects who screened positive were extensively evaluated to confirm or exclude the presence of stroke. Further
Journal of Stroke and CerebrovascularDiseases,Vol. 7, No. 3 (May-June), 1998: pp 196-199
197
P R E V A L E N C E OF S T R O K E I N THE Y O U N G
previous diagnoses. TMMedically trained persons administered the screening instrument.
~_~ TOTALEl IGJBI.EPOPULATION AGED<40 YRS ON NOVEMBER1,1987 N = 16.095
Phase 2 a n d Clinical D i a g n o s i s N = 14,6321"
]j "
SCREENED N = 1,283"
N=288
1
/fADEGUA'rEJNFORMA'nON-'~~ N = 284
Examination Oth. . . . . . . . .
~,.
~
273 11
~
[ INADEQUATEINFORMATION\ FROMALL SOURCES d~.~. N:4, J
STROKE EXCLUDED N=278
.
DIAGNOSISOF STRORF. N=6
Figure1. Steps of the door-to-door two-phase prevalence survey. For each step, the number of subjects involved is indicated. *One subject died between the prevalence day and the day of actual contact, 487 refused to participate, and 775 could not be traced, fThis number included 4,541 children (i.e., subjects 12 years of age or younger). In addition, 489 subjects older than 12 years of age were screened indirectly for the following reasons: six died between November 1, 1987 and the day of actual contact, 14 refused to participate, 417 could not be traced, and 417 were unable to answer the screening questions. Y;Two subjects refused to be clinically examined, and two could not be traced.
details on the study population and survey methods are described elsewhere. TM
Subjects who screened positive were clinically examined by board-certified neurologists using a standardized protocol. For subjects who could not be clinically examined, relevant medical information was sought from close relatives, general practitioners, and hospital records when available. 21 A panel of senior neurologists and one epidemiologist adjudicated each case to increase reliability across centers. 18 We defined stroke, using the 1980 World Health Organization criteria, 22 as follows: sudden or rapid-onset focal brain dysfunction due to occlusive or hemorrhagic lesions of the vascular supply, or global brain dysfunction with documentation of subarachnoid or intraventricular hemorrhage, lasting for more than 24 hours or leading to death within 24 hours. Transient ischemic attacks and posttraumatic cerebrovascular events were excluded. The diagnosis of stroke was considered definite if (1) stroke had been previously diagnosed by a physician and the study neurologist agreed with the diagnosis or (2) clinical signs consistent with the diagnosis of stroke sequelae were present at the moment of the evaluation, and any other explanation could be reasonably excluded. All cases had a definite diagnosis. As regards the pathological classification, we basically considered stroke as hemorrhagic when the presence of blood was documented by lumbar puncture, computed tomographj6 or magnetic resonance imaging; it was considered ischemic when the absence of blood was documented by imaging techniques, and of uncertain type when diagnostic information was incomplete.
Phase I a n d S c r e e n i n g I n s t r u m e n t Data Analysis
The instrument used to screen for stroke was part of a larger instrument designed to detect several neurological diseases. 19 The screening instrument was validated in a hospital sample of 22 subjects aged 36 to 80 years who had experienced a previous stroke, showing a sensitivity of 96% and a specificity of 86%. 2o The screening instrument addressed stroke through questions about history of impaired consciousness, changes of speech, paralysis of face, drooping of mouth, and weakness or paralysis of limbs, as well as by simple tasks such as holding the arms extended, distinguishing textures, touching finger to nose, walking heel-to-toe, standing with the eyes open, and standing with eyes closed. The subject was also asked whether a stroke had ever been diagnosed. All individuals positive in any of these questions or tasks were sent to phase 2. Children (i.e., subjects 12 years of age or younger) followed a different screening procedure: a knowledgeable person, usually the mother or grandmother, answered questions about impaired consciousness and
To obtain more stable prevalence figures, we pooled the data from Riposto, Santa Teresa di Riva, and Terrasini. We calculated overall and age-specific prevalence rates, 95% confidence limits, and the rate after standardization to the 1981 Italian population.
Results Figure 1 shows the steps of the study. Of the 16,095 resident subjects younger than 40 years, we screened, either directly or indirectly, 14,832 individuals (92%). The remaining 1,263 subjects were excluded from the study. Of the subjects screened, 288 (2%) were positive for stroke and went on to phase 2. Almost all of these (99%) were clinically evaluated. Of 11 who could not be examined, we achieved reliable clinical information indirectly, through close relatives or the family physician. We were unable to obtain adequate clinical information on two subjects who
198
F. PATTI ET AL. Table 1. Cases, population by age and sex, total and age-specific prevalence rates Men
Women
Both sexes
Age-group
Cases
Population
Cases
Pop,
Cases
Pop.
Prevalence (• 100,000)
0-9 10-19 20-29 30-39 Total
0 1 0 2 3
1,759 2,248 1,915 1,662 7,584
0 0 1 2 3
1,638 2,047 t,901 1,662 7,248
0 1 1 4 6
3,397 4,295 3,816 3,324 14,832
0 23.28 26,2 120.33 40.45"I"
*95% confidence limits 14.84 to 88.06. tStandardized rate to 1981 Italian population, 41.17. survey is the first Italian large-scale investigation on the total population of three municipalities. Our prevalence figure (40.5 / 100,000) appears fairly comparable with those from the only two methodologically similar studies performed so far on young populations. The Copiah County study, 16 a house-to-house survey conducted on a biracial American population, found a prevalence rate in the young ((3 to 34 years) of 36.8/100,000; race-specific prevalence was higher for blacks, In the Indian region of Kashmir, 23 a similar door-todoor survey of a large rural population ascertained among people aged 15 to 39 years a prevalence rate of 41/100,000. Even if these unstandardized prevalence rates are similar, it must be pointed out that cause and survival after stroke can be very different in different populations, and therefore prevalence rates do not reflect incidence rates. Unlike prevalence surveys, many incidence studies have been done in Italy and worldwide. Two Italian studies have addressed specifically stroke incidence in the young. In Florence, Nencini et al. 24 reported in people aged 15 to 44 years an annual incidence rate of 8.8/ 100,000. In the Reggio Emilia area, Guidetti et al. 25 found an incidence rate of 13.6 in the same age-group. The reported rates, even if calculated on age-groups partly different from ours, are fairly consistent with our
refused the examination and two who were unreachable. Of 284 subjects examined in phase 2, six (three men and three women) had experienced one or more strokes in their life before the prevalence day (lifetime prevalence). Table 1 shows the number of cases, population, and prevalence by age class from 0 to 39 years. Prevalence figures become higher with advancing age; the overall rate was 40.5/100,000 inhabitants (95% confidence limits, 14.84 to 88.06). All patients had been hospitalized at the time of the stroke onset. In Table 2, some dinicopathological features are shown. All but one had their onset in the third and fourth decades of life. As to pathological type, half of the strokes were hemorrhagic (two subarachnoid hemorrhages and one intracerebral hemorrhage); one experienced a single recurrence; five exhibited sufficient autonomy in movement.
Discussion Prevalence of stroke in younger patients is difficult to assess reliably because it is a rare disease, estimated to affect 20 to 100 subjects of every 100,000. 4"13'14"16,23 This means that large populations must be studied to collect a sufficient number of cases. Few door-to-door prevalence studies of cerebrovascular diseases have been performed worldwide. The current
Table 2. Clinical features of young stroke patients Sex
Age (yr)
Age at onset
Known risk factors
M F
39 24
35 22
F
37
28
F
35
33
M M
35 17
25 4
None Smoking Alcohol abuse Family history Family history Pregnancy Hypertension Hyperlipidemia Smoking None
Imaging tests
Pathological type
Recurrences
Walking
Occupation
CT scan CT scan
SAH (left silvian aneurysm) ICH
0 0
With aids No aids
Employee Employee
Not available
Uncertain
0
No aids
Housewife
CT scan
CI
1
No aids
Housewife
Not available Angiography
Uncertain SAH (right silvian aneurysm)
0 0
No aids No aids
No activity Student
Abbreviations: SAH, subarachnoid hemorrhage; ICH, intracerebral hemorrhage; CI, cerebral infarction.
PREVALENCE OF STROKE IN THE YOUNG
results, if we consider that one-fifth to one-fourth of young stroke patients die, 11,24,26and, among the survivors, those achieving a complete recovery may easily go undetected in a survey performed years later. Our study confirms the low prevalence of stroke in young people; yet incidence and prevalence rates rapidly increase with age. Among the survivors, recovery seems generally good, but relapses are possible. Hemorrhagic events, and particularly subarachnoid hemorrhage, are highly represented,
References 1. Adams RD, Victor M, Ropper AH~ Cerebrovascular diseases. In: Principles of Neurology. New York: McGrawHill, 1997, 2. Davis HP, Hachinski V. Epidemiology of cerebrovascular disease. In: Anderson DW, Schoenberg DG, eds. Neuroepidemiology: A Tribute to Bruce Schoenberg. Boca Raton: CRC Press, 1991;28-53, 3. Hachinski V. The young stroke. In: Hachinski V, Norris JW, eds. Acute stroke. Philadelphia: FA Davis, 1985:141163. 4. Salam-Adams M, Adams R, Cerebrovascular disease by age group. In: Wynken PJ, Bruyn GW, eds. Handbook of clinical neurology. Amsterdam: Elsevier Science Publishers, 1988;53:27-46. 5. D'Alessandro G, Di Giovanni M, Roveyaz L, et al. Incidence and prognosis of stroke in the Valle d'Aosta, Italy; First-year results of a community-based study. Stroke 1992;23:1712-1715. 6. Lauria G, Gentile Ivl, Fassetta G, et al. Incidence and prognosis of stroke in the Belluno province, Italy: Firstyear results of a community-based study. Stroke 1995;26: 1787-1793. 7. Oxfordshire Community Stroke Project. Incidence of stroke in Oxfordshire: First year's experience of a communit,/stroke register, BMJ 1983;287:713-717, 8, Ricci S, Celani MG, La Rosa F, et al. SEPIVAC: A community-based study of stroke incidence in Umbria, Italy. J Neurol Neurosurg Psychiatry 1991;54:695-698. 9. Carolei A, Marini C, Ferranti E, et al. A prospective study of cerebral ischemia in the young: Analysis of pathogenic determinants. Stroke 1993;24:362-367. 10. Gautier JC, Pradat-Diehl P, Loron P, et al. Accidents vasculaires c6r6braux des sujets jeunes: Une 6tude de 133 patients de 9 a 45 ans. Rev Neurol (Paris) 1989;145:437442.
199 11. Kappelle LJ, Adams HE Heffner ML, et al. Prognosis of young adults with ischemic stroke: A long-term follow-up study assessing recurrent vascular events and functional outcome in the Iowa registry of stroke in young adults. Stroke 1994;25:1360-1365. 12. Radhakrishnan K, Ashok PE Sridharan R, et al. Stroke in the young: Incidence and pattern in Benghazi, Lybia. Acta Neurol Scand 1986;73:434-438. 13. Bharucha NE, Bharucha EE Bharucha AE, et al. Prevalence of stroke in the Parsi community of Bombay. Stroke 1988;19:60-62. 14. Li S, Schoenberg BS, Wang C, et al. Cerebrovascular disease in the People's Republic of China: Epidemiologic and dinical features. Neurology 1985;35:1708-1713. 15. Razdan S, Koul RL, Motta A, et al. Cerebrovascular disease in rural Kashmir, India. Stroke 1989;20:1691-1693. 16. Schoenberg BS, AndersonDW, HaererAF. Racial differentials in the prevalence of stroke: Copiah County, Mississippi. Arch Neurol 1986;43:565-568. 17. Matias-Guiu J, Oltra A, Falip R, et al. Occurrence of transient ischemic attacks in Alcoi: Descriptive epidemiology. Neuroepidemiology 1994;13:34-39. 18. Meneghini E Rocca WA, Grigoletto F, et al. Door-to-door prevalence survey of neurological diseases in a Sicilian population: Background and methods. Neuroepidemiology 1991;10:70-85. 19. World Health Organization. Research protocol for measuring the prevalence of neurological disorders in developing countries. Geneva: Neuroscience Programme. World Health Organization, 1981. 20. Meneghini F, Rocca WA, Anderson DW, et al. Validating screening instruments for neuroepidemiological surveys: Experience in Sicily. j Clin Epidemiol 1992;45:319-331. 21, Grigoletto F, Anderson DW, Rocca WA, et al. Attrition and use of proxy respondents and auxiliary information in the Sicilian Neuroepidemiologic Study. Am J Epidemio11994;139:219-228. 22. Aho K, Harmsa P, Hatano S, et al. Cerebrovascular disease in the community: Results of a WHO collaborative study. Bull WHO 1980;58:113. 23. Koul R, Motta A, Razdan S. Epidemiology of young strokes in rural Kashmir, India. Acta Neurol Scand 1990;82:i-3. 24. Nencini P, Inzitari D, Baruffi MC, et al. Incidence of stroke in young adults in Florence, Italy. Stroke 1988;19:977-981. 25. Guidetti D, Baratti M, Zucco R, et al, Incidence of stroke in young adults in the Reggio Emilia area, Northern italy. Neuroepidemiology 1993;12:82-87. 26. Leno C, Berciano J, Combarros O, et al. A prospective study of stroke in young adults in Cantabria, Spain. Stroke 1993;24:792-795.
Few epidemiological reports focus on the prevalence of stroke in the young population. As part of a neuroepidemiological survey on the total population of three Sicilian municipalities, we assessed the prevalence of stroke in the young, describing the clinical features of each patient. We screened 14,832 subjects younger than 40 years with a door-to-door method and a two-phase study design. Phase 1 consisted of a questionnaire and a brief neurological examination; phase 2 was an extensive evaluation performed by a neurologist. On the prevalence day (November 1, 1987), we ascertained six cases of stroke (prevalence rate, 40.5/100,000). Three were hemorrhagic, one ischemic, and two of uncertain type. Recovery was good in five patients; only one needed aids for walking. Stroke is uncommon in the young, but its prevalence rapidly increases in an age-related fashion. Hemorrhagic lesions are probably more represented in this age-group. Survivors tend to show good motor recovery. Key Words: Epidemiology--Stroke--u
Despite a slow, progressive decrease, cerebrovascular diseases still represent the third most c o m m o n cause of mortality in most industrialized countries I and the main cause of chronic disability in the elderly; nonetheless, acute cerebrovascular events m a y occur in younger persons as w e l l accounting for approximately 3% to 5% of all strokes. 2-4 Even though m a n y epidemiological studies have addressed incidence, risk factors, and outcome of stroke at all ages 5-s or in the y o u n g o n l y 9-12 in well-defined populations, few authors have investigated the prevalence of stroke with a door-to-door methodology. 13-17 Only a comprehensive investigation with a door-todoor methodology on a sufficiently large population m a y yield reliable data about prevalence of an u n c o m m o n neurological disease such as stroke in childhood and young adulthood; similar data could be suitable for comparisons among different populations. From the Departments of Neurology, University of Catania, University of Palermo, University of Messina, University of Naples; and the Department of Statistical Sciences,University of Padua, Italy. Received July 21, 1997; accepted October 28, 1997. Address reprint requests to Arturo Reggio, Istituto di Scienze Neurologiche, Po]iclinico Universitario, viale Andrea Doria, 6-95125 Catania, Italy. Copyright 9 1998by National Stroke Association 1052-3057/98 / 0703-000653.00/ 0
196
The current report is part of a door-to-door epidemiological investigation on the total population of three Sicilian municipalities, designed to detect the prevalence and clinical features of some common neurological diseases. TM The aim of this report is to provide data on the morbidity of stroke in younger patients and to describe the clinical findings in these patients.
Methods
Population Description and General Study Design The study population consisted of all subjects younger than 40 years residing in the Sicilian municipalities of Riposto (Catania province), Santa Teresa di Riva (Messina province), and Terrasini (Palermo province) as of November 1, 1987. Resident lists maintained in each municipality served as a survey frame along with data from the 1981 Census of the Italian population. We ascertained cases of stroke through a door-to-door survey with a two-phase design (Fig 1). During phase 1, a screening instrument was administered to eligible subjects. In phase 2, all subjects who screened positive were extensively evaluated to confirm or exclude the presence of stroke. Further
Journal of Stroke and CerebrovascularDiseases,Vol. 7, No. 3 (May-June), 1998: pp 196-199
197
P R E V A L E N C E OF S T R O K E I N THE Y O U N G
previous diagnoses. TMMedically trained persons administered the screening instrument.
~_~ TOTALEl IGJBI.EPOPULATION AGED<40 YRS ON NOVEMBER1,1987 N = 16.095
Phase 2 a n d Clinical D i a g n o s i s N = 14,6321"
]j "
SCREENED N = 1,283"
N=288
1
/fADEGUA'rEJNFORMA'nON-'~~ N = 284
Examination Oth. . . . . . . . .
~,.
~
273 11
~
[ INADEQUATEINFORMATION\ FROMALL SOURCES d~.~. N:4, J
STROKE EXCLUDED N=278
.
DIAGNOSISOF STRORF. N=6
Figure1. Steps of the door-to-door two-phase prevalence survey. For each step, the number of subjects involved is indicated. *One subject died between the prevalence day and the day of actual contact, 487 refused to participate, and 775 could not be traced, fThis number included 4,541 children (i.e., subjects 12 years of age or younger). In addition, 489 subjects older than 12 years of age were screened indirectly for the following reasons: six died between November 1, 1987 and the day of actual contact, 14 refused to participate, 417 could not be traced, and 417 were unable to answer the screening questions. Y;Two subjects refused to be clinically examined, and two could not be traced.
details on the study population and survey methods are described elsewhere. TM
Subjects who screened positive were clinically examined by board-certified neurologists using a standardized protocol. For subjects who could not be clinically examined, relevant medical information was sought from close relatives, general practitioners, and hospital records when available. 21 A panel of senior neurologists and one epidemiologist adjudicated each case to increase reliability across centers. 18 We defined stroke, using the 1980 World Health Organization criteria, 22 as follows: sudden or rapid-onset focal brain dysfunction due to occlusive or hemorrhagic lesions of the vascular supply, or global brain dysfunction with documentation of subarachnoid or intraventricular hemorrhage, lasting for more than 24 hours or leading to death within 24 hours. Transient ischemic attacks and posttraumatic cerebrovascular events were excluded. The diagnosis of stroke was considered definite if (1) stroke had been previously diagnosed by a physician and the study neurologist agreed with the diagnosis or (2) clinical signs consistent with the diagnosis of stroke sequelae were present at the moment of the evaluation, and any other explanation could be reasonably excluded. All cases had a definite diagnosis. As regards the pathological classification, we basically considered stroke as hemorrhagic when the presence of blood was documented by lumbar puncture, computed tomographj6 or magnetic resonance imaging; it was considered ischemic when the absence of blood was documented by imaging techniques, and of uncertain type when diagnostic information was incomplete.
Phase I a n d S c r e e n i n g I n s t r u m e n t Data Analysis
The instrument used to screen for stroke was part of a larger instrument designed to detect several neurological diseases. 19 The screening instrument was validated in a hospital sample of 22 subjects aged 36 to 80 years who had experienced a previous stroke, showing a sensitivity of 96% and a specificity of 86%. 2o The screening instrument addressed stroke through questions about history of impaired consciousness, changes of speech, paralysis of face, drooping of mouth, and weakness or paralysis of limbs, as well as by simple tasks such as holding the arms extended, distinguishing textures, touching finger to nose, walking heel-to-toe, standing with the eyes open, and standing with eyes closed. The subject was also asked whether a stroke had ever been diagnosed. All individuals positive in any of these questions or tasks were sent to phase 2. Children (i.e., subjects 12 years of age or younger) followed a different screening procedure: a knowledgeable person, usually the mother or grandmother, answered questions about impaired consciousness and
To obtain more stable prevalence figures, we pooled the data from Riposto, Santa Teresa di Riva, and Terrasini. We calculated overall and age-specific prevalence rates, 95% confidence limits, and the rate after standardization to the 1981 Italian population.
Results Figure 1 shows the steps of the study. Of the 16,095 resident subjects younger than 40 years, we screened, either directly or indirectly, 14,832 individuals (92%). The remaining 1,263 subjects were excluded from the study. Of the subjects screened, 288 (2%) were positive for stroke and went on to phase 2. Almost all of these (99%) were clinically evaluated. Of 11 who could not be examined, we achieved reliable clinical information indirectly, through close relatives or the family physician. We were unable to obtain adequate clinical information on two subjects who
198
F. PATTI ET AL. Table 1. Cases, population by age and sex, total and age-specific prevalence rates Men
Women
Both sexes
Age-group
Cases
Population
Cases
Pop,
Cases
Pop.
Prevalence (• 100,000)
0-9 10-19 20-29 30-39 Total
0 1 0 2 3
1,759 2,248 1,915 1,662 7,584
0 0 1 2 3
1,638 2,047 t,901 1,662 7,248
0 1 1 4 6
3,397 4,295 3,816 3,324 14,832
0 23.28 26,2 120.33 40.45"I"
*95% confidence limits 14.84 to 88.06. tStandardized rate to 1981 Italian population, 41.17. survey is the first Italian large-scale investigation on the total population of three municipalities. Our prevalence figure (40.5 / 100,000) appears fairly comparable with those from the only two methodologically similar studies performed so far on young populations. The Copiah County study, 16 a house-to-house survey conducted on a biracial American population, found a prevalence rate in the young ((3 to 34 years) of 36.8/100,000; race-specific prevalence was higher for blacks, In the Indian region of Kashmir, 23 a similar door-todoor survey of a large rural population ascertained among people aged 15 to 39 years a prevalence rate of 41/100,000. Even if these unstandardized prevalence rates are similar, it must be pointed out that cause and survival after stroke can be very different in different populations, and therefore prevalence rates do not reflect incidence rates. Unlike prevalence surveys, many incidence studies have been done in Italy and worldwide. Two Italian studies have addressed specifically stroke incidence in the young. In Florence, Nencini et al. 24 reported in people aged 15 to 44 years an annual incidence rate of 8.8/ 100,000. In the Reggio Emilia area, Guidetti et al. 25 found an incidence rate of 13.6 in the same age-group. The reported rates, even if calculated on age-groups partly different from ours, are fairly consistent with our
refused the examination and two who were unreachable. Of 284 subjects examined in phase 2, six (three men and three women) had experienced one or more strokes in their life before the prevalence day (lifetime prevalence). Table 1 shows the number of cases, population, and prevalence by age class from 0 to 39 years. Prevalence figures become higher with advancing age; the overall rate was 40.5/100,000 inhabitants (95% confidence limits, 14.84 to 88.06). All patients had been hospitalized at the time of the stroke onset. In Table 2, some dinicopathological features are shown. All but one had their onset in the third and fourth decades of life. As to pathological type, half of the strokes were hemorrhagic (two subarachnoid hemorrhages and one intracerebral hemorrhage); one experienced a single recurrence; five exhibited sufficient autonomy in movement.
Discussion Prevalence of stroke in younger patients is difficult to assess reliably because it is a rare disease, estimated to affect 20 to 100 subjects of every 100,000. 4"13'14"16,23 This means that large populations must be studied to collect a sufficient number of cases. Few door-to-door prevalence studies of cerebrovascular diseases have been performed worldwide. The current
Table 2. Clinical features of young stroke patients Sex
Age (yr)
Age at onset
Known risk factors
M F
39 24
35 22
F
37
28
F
35
33
M M
35 17
25 4
None Smoking Alcohol abuse Family history Family history Pregnancy Hypertension Hyperlipidemia Smoking None
Imaging tests
Pathological type
Recurrences
Walking
Occupation
CT scan CT scan
SAH (left silvian aneurysm) ICH
0 0
With aids No aids
Employee Employee
Not available
Uncertain
0
No aids
Housewife
CT scan
CI
1
No aids
Housewife
Not available Angiography
Uncertain SAH (right silvian aneurysm)
0 0
No aids No aids
No activity Student
Abbreviations: SAH, subarachnoid hemorrhage; ICH, intracerebral hemorrhage; CI, cerebral infarction.
PREVALENCE OF STROKE IN THE YOUNG
results, if we consider that one-fifth to one-fourth of young stroke patients die, 11,24,26and, among the survivors, those achieving a complete recovery may easily go undetected in a survey performed years later. Our study confirms the low prevalence of stroke in young people; yet incidence and prevalence rates rapidly increase with age. Among the survivors, recovery seems generally good, but relapses are possible. Hemorrhagic events, and particularly subarachnoid hemorrhage, are highly represented,
References 1. Adams RD, Victor M, Ropper AH~ Cerebrovascular diseases. In: Principles of Neurology. New York: McGrawHill, 1997, 2. Davis HP, Hachinski V. Epidemiology of cerebrovascular disease. In: Anderson DW, Schoenberg DG, eds. Neuroepidemiology: A Tribute to Bruce Schoenberg. Boca Raton: CRC Press, 1991;28-53, 3. Hachinski V. The young stroke. In: Hachinski V, Norris JW, eds. Acute stroke. Philadelphia: FA Davis, 1985:141163. 4. Salam-Adams M, Adams R, Cerebrovascular disease by age group. In: Wynken PJ, Bruyn GW, eds. Handbook of clinical neurology. Amsterdam: Elsevier Science Publishers, 1988;53:27-46. 5. D'Alessandro G, Di Giovanni M, Roveyaz L, et al. Incidence and prognosis of stroke in the Valle d'Aosta, Italy; First-year results of a community-based study. Stroke 1992;23:1712-1715. 6. Lauria G, Gentile Ivl, Fassetta G, et al. Incidence and prognosis of stroke in the Belluno province, Italy: Firstyear results of a community-based study. Stroke 1995;26: 1787-1793. 7. Oxfordshire Community Stroke Project. Incidence of stroke in Oxfordshire: First year's experience of a communit,/stroke register, BMJ 1983;287:713-717, 8, Ricci S, Celani MG, La Rosa F, et al. SEPIVAC: A community-based study of stroke incidence in Umbria, Italy. J Neurol Neurosurg Psychiatry 1991;54:695-698. 9. Carolei A, Marini C, Ferranti E, et al. A prospective study of cerebral ischemia in the young: Analysis of pathogenic determinants. Stroke 1993;24:362-367. 10. Gautier JC, Pradat-Diehl P, Loron P, et al. Accidents vasculaires c6r6braux des sujets jeunes: Une 6tude de 133 patients de 9 a 45 ans. Rev Neurol (Paris) 1989;145:437442.
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