Prevalence of presenile dementia in a tertiary outpatient clinic

Abstract

-There are very few reports about prevalence of presenile dementia in Brazil. We reviewed files of patients evaluated with early onset of cognitive impairment in our institution. Among 141 patients (61% males) there was no difference between gender by age at onset or at first evaluation. We have observed an increasing number of patients after 50 years. The most frequent causes were: vascular dementia (36.9%), Alzheimer's disease (20.3%) and traumatic brain injury (9.2%). There was difference among dementia type by age of onset and first evaluation, educational level and length of dementia. These results may be compared with those from other neurologic services in order to replicate or confirm these results.KEY WORDS: presenile dementia, vascular dementia, Alzheimer's disease, epidemiology. Prevalência de demência pré-senil num ambulatório terciárioRESUMO -Em nosso meio há raros estudos que verifiquem quais as causas mais prevalentes de demência pré-senil. Avaliamos retrospectivamente os prontuários de pacientes com início precoce de alterações cognitivas, ambulatório de Neurologia da Cognição do Hospital Santa Marcelina. Entre os 141 sujeitos (61% de homens) não houve diferença quanto às idades de início e à primeira consulta e escolaridade entre os sexos. Observamos aumento no número de demência após os 50 anos. A causa mais freqüente foi vascular (36,9%), seguida por doença de Alzheimer (20,3%) e secundária a trauma cranio encefálico (9,2%). Houve diferença entre os tipos de demência quanto à idade na primeira consulta e idade de início, escolaridade e duração do quadro. Ao contrário de outros estudos o diagnóstico mais freqüente foi demência vascular. Novos estudos em nosso meio deverão ser realizados para avaliar este achado nas demências de início precoce.PALAVRAS-CHAVE: demência pré-senil, demência vascular, doença de Alzheimer, epidemiologia.Dementia is a disorder of greater prevalence in older subjects, but many cases can begin in an early age, affecting people in a productive phase of their lives. A syndrome characterized by many cognitive deficits of sufficient severity to interfere with daily life activities and in quality of life. It is a public health problem due its expensive treatment and dependence of patients for governmental sources for sustainability. There are a few studies in epidemiology of presenile dementia comparing to an older onset or familiar Alzheimer's disease (AD) [1][2][3] . The prevalence of presenile dementia is lower that ones with onset in the elderly. Harvey et al. 4 reported that the prevalence increases exponentially between 45 to 60 years of age; this finding was replicated by another three epidemiological studies [5][6][7] . The most frequent diagnosis in early onset dementia is:Alzheimer's disease, followed by vascular dementia (VaD) and frontotemporal dementia (FTD) 8 . There are no studies analyzing the prevalence of presenile dementia in our country in a search in MEDLINE. Other authors have reported diagnostic prevalence in senile dementia or overall rates o...

The Accurate Diagnosis of Early-Onset Dementia

“…Among 948 U.S. veterans, 278 (30%) had EOD [1], and, among 619 patients in England, the proportion of patients with EOD was 28.6% [4]. In another report of 311 patients in Brazil, the proportion of patients with EOD was a high of 46.6% [5]. These studies indicate that there are significant proportions of patients with EOD at least among select populations.…”

“…Despite the importance, clinicians misdiagnose many if not most patients with EOD early in their course [2,5,10,[15][16][17]. Although clinical criteria exist for the most common EODs, misdiagnosis is common even at tertiary centers [2].…”

“…TBI is an important cause of EOD. In some series, dementia from TBI comprises 9-24% of EODs [1,5,28]. Since TBI is the most common cause of neurologic illness in young people, it is not surprising that it is a significant cause of chronic deficits in cognition.…”

“…Moreover, EOD is more of a problem and more common than previously realized. Recent clinical reports indicate a significant proportion of EOD patients compared to LOD patients [1,4,5]. Among 948 U.S. veterans, 278 (30%) had EOD [1], and, among 619 patients in England, the proportion of patients with EOD was 28.6% [4].…”

“…For example, the World Health Organization continues to distinguish between "dementia in Alzheimer's disease with early onset before age of 65" vs. "dementia in Alzheimer's disease with late onset" [6]. The overall prevalence of EOD is low compared to LOD, but still considerable [5,[7][8][9]. The prevalence of EOD is about 67 to 81 per 100,000 persons in the 45 to 65 year old age group with exponential increases beginning at age 35 [4,[10][11][12][13].…”