Alzheimer Disease

Abstract

A LZHEIMER DISEASE (AD), THE most common cause of dementia in the elderly, is a progressive neurodegenerative disorder that gradually robs the patient of cognitive function and eventually causes death. We review theepidemiology,clinicalfeatures,pathophysiology, and treatment of AD. Incidence, Prevalence, and Economic ImpactAlzheimer disease accounts for 60% to 70% of cases of progressive cognitive impairment in elderly patients. The total prevalence of AD in the United States is estimated at 2.3 million (range, 1.09-4.8 million).1 The prevalence of AD doubles every 5 years after the age of 60 increasing from a prevalence of 1% among those 60-to 64-years-old to up to 40% of those aged 85 years and older. 2The disease is more common among women than men by a ratio of 1.2 to 1.5. 3The number of new cases per year is estimated at 360000 equating to 980 new cases per day or 40 new cases every hour. The population of patients with AD will nearly quadruple in the next 50 years if the current trend continues. 1The direct costs for the care of patients in 1991 were calculated at US $20.6 billion and the total cost was calculated to be $76.3 billion. 4 Most direct costs of care for patients with AD are absorbed by the expense of nursing home care, approximately $47 000 per patient per year. 5Several risk factors for AD have been identified in epidemiologic studies in addition to age and female sex. The most potent risk factor is the presence of the apolipoprotein ⑀4 (APOE ⑀4) allele. Of its 3 forms-⑀2, ⑀3, and ⑀4-only the ⑀4 allele increases the likelihood of developing AD. The lifetime risk of AD for an individual without the ⑀4 allele is approximately 9%; the lifetime risk of AD for an individual carrying at least 1 ⑀4 allele is 29%.6 While representing a substantial risk of AD, the ⑀4 genotype is not sufficiently specific or sensitive for the diagnosis of AD to allow its use as a diagnostic test.7 Moreover, the ⑀4 allele appears to increase the risk of AD more in white and Asian populations than in black and Hispanic populations. Other risk factors implicated in a variety of studies include head injury, low serum levels of folate and vitamin B 12 , elevated plasma and total homocysteine levels, family history of AD or demen-

Association of Being Accompanied at Medical Consultation and Having Memory Complaints With Cognitive Impairment in Elderly Brazilian Outpatients

“…In fact, we observed that the group of accompanied patients was older and less educated than those who were alone, corroborating previous findings 9,10,21. It has already been observed that visit companions tend to accompany patients who are especially vulnerable,22 and dementia and/or mild cognitive impairment are associated with substantial morbidity, contributing to a marked vulnerability 23…”

Comparing the Neuropsychiatric Profile of Patients with Alzheimer Disease Who Present Spared versus Impaired Executive Functioning

“…Taking into account the selective involvement of the ventromedial prefrontal cortex in the latter condition during the earlier stages of the disease and considering the marked neuropathological changes that have been described within the frontal cortex of “frontal” AD patients [5], it comes as no surprise that stereotypic and aberrant motor behavior—which strongly depend on frontal cortex activity—were more prominent in dysexecutive AD patients than in those who show spared executive functions. In this sense, the results of this preliminary study support the idea of a frontal subgroup of AD patients who may have more involvement of the frontal lobes [5, 6] and hence exhibit more marked neuropsychiatric and behavioral disturbances [2, 9, 11, 23] associated with the circuitry within the anterior regions of the brain. …”

Lifetime Risk and Duration of Chronic Disease and Disability

“…The projected length of IADL difficulty, in fact, exceeds projected years with dementia (4.8 vs. 4.4 years, respectively). This finding is consistent with the gradual onset of disease (Hebert et al 1995), with mild and even moderate dementia not always recognized in clinical practice (Cummings & Cole, 2002). Results from a prospective cohort study following elders over a 10-year period suggest that limitations in IADLs are an early indicator of incipient dementia (Peres et al 2008).…”