ArticlesThe Initial Recognition and Diagnosis of Dementia
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Recognizing dementia
The most difficult aspect of the diagnosis of dementia is recognizing that the patient is experiencing lapses in cognition. There are barriers to the detection of dementia in routine practice.3., 4. Rarely do patients seek medical attention for the symptoms of dementia. Lack of insight on the part of the patient is a common early feature. Family members usually seek out medical attention. However, family members are often tardy in recognizing that the changes in the affected individuals
Aging
Memory problems in the elderly are blamed most often on normal aging. The alleged inevitability of impaired memory with aging creates a ready explanation for cognitive lapses. Two decades of research in cognitive psychology has established that normal aging is not associated with dramatic declines in recent memory or judgment.8 The interpretation of what is expected in cognitive aging is complicated by methodologic challenges. The elderly are more likely to have concurrent illnesses that can
The differential diagnosis of dementia
The differential diagnosis of dementia in the elderly involves 5 major syndromes (Table 1)that encompass the commonly encountered presentations of subacute- or gradual-onset cognitive impairment. This scheme does not apply to the differential diagnosis of dementia in younger patients (individuals 45–50 years old). In younger patients, there are a number of diseases that must be considered that will not be discussed here.
Alzheimer’s disease: the prototypical dementia
Alzheimer’s disease (AD) is the most common form of dementia in the elderly. Approximately 60–80% of dementia patients in epidemiologic studies have AD.16., 17., 18., 19., 20., 21., 22.The Diagnostic and Statistical Manual of Mental Disorders, Fourth edition (DSM-IV) criteria for AD1., 23.(Table 2)require impairment of recent memory and at least one other cognitive or behavioral abnormality. The DSM-IV criteria refer to the additional deficits as aphasia, apraxia, and agnosia. However, these
Rapidly progressive dementias
Rapidly progressive dementias are the disorders of cognitive dysfunction in which symptoms and signs are present for only a few days or months (Table 4). Within this category are the dementias termed “treatable” in earlier diagnostic schemes. Metabolic and toxic disturbances are the most common of this group.30 A thorough history aimed at identifying antecedents and associated symptoms of the disorders listed in Table 4 will often provide the most accurate indication of the correct diagnosis.
Dementias associated with stroke
Vascular dementia is a controversial diagnosis. Because of the complexity of establishing the causal links between cerebral infarctions of various sizes and locations, neuropathologists vary in how they diagnose it. Furthermore, the presence of some AD pathology in most cases of vascular dementia raises the issue of what constitutes the minimal burden of AD changes necessary to make that diagnosis. Depending upon the degree of AD pathology, the contribution of vascular lesions to the dementia
Dementias associated with Parkinsonism
Extrapyramidal signs, which are often referred to collectively as Parkinsonism, are very common in the elderly.42 In roughly 30% of individuals with Parkinsonism, dementia will develop.43 The proportion of patients with Parkinson’s disease who are cognitively impaired is likely to be underrecognized because of the overwhelming problems with motor disturbances. Recognition of dementia in Parkinson’s disease is important because management and treatment issues are different from those for AD.
The
Frontotemporal dementias
The frontotemporal dementias (FTD) are much less common than either AD, vascular dementia, or dementia associated with Parkinsonism. It is diagnosed on the basis of historical and mental status examination evidence of disproportionate impairment of reasoning and judgment relative to anterograde amnesia (amnesia occurring after a trauma or disease).50 The term “dysexecutive syndrome” has been applied to the cognitive syndrome of patients with FTD who have grossly disturbed abstract reasoning,
Progressive aphasia
Patients with primary progressive aphasia are often misdiagnosed as having suffered from silent stroke. Alternatively, they are simply labeled as having AD, to the chagrin of families who see how different their relatives are from AD patients. The distinctive features of progressive aphasia, in contrast to AD, are the relative excess of dysfunction of expressive language and the relative paucity of anterograde amnesia.53 There is almost always an initial element of nonfluency. This takes the
Signs and symptoms of dementia by history and mental status examination in differential diagnosis
The assessment of a suspected dementia patient revolves around basic history and mental status examination techniques. There is no widely used history-taking instrument for dementia. Table 9covers the major areas of impairment to be reviewed with a relative or friend of the patient. A knowledgeable informant who can speak candidly about these topics is essential for establishing a diagnosis. Often, the queries in Table 9 are best discussed with the patient absent; the informants may not be
The neurologic examination
The remainder of the neurologic examination other than mental status is necessary mainly for differentiating vascular dementia and dementia associated with Parkinsonism from AD. The neurologic examination in a patient with vascular dementia may be unremarkable or there may be signs of hemiparesis, hemianesthesia, hemianopia, unilateral neglect, diplopia, dysphagia, dysarthria, facial palsy, ptosis, or pupillary abnormalities. None of these occurs exclusively in stroke, however, so that the
Laboratory diagnostic assessment
The American Academy of Neurology guidelines62 for the diagnosis of dementia make a number of specific recommendations (Table 11). The role of imaging studies is hotly debated.63., 64. Although neuroimaging is not routinely recommended, there are instances for its consideration for practicing physicians. The presence of other neurologic signs or symptoms (headaches, seizures, and abnormal motor exam findings), together with cognitive impairment, should prompt an imaging study. The importance of
Conclusions
Early recognition of dementia requires a high index of suspicion, necessary time to interview family members, and skill in assessing mental status. The differential diagnosis of dementia first requires eliminating depression and acute confusional states as principal diagnoses. Rapidly evolving dementias, vascular dementias, and dementias associated with Parkinsonism are the major categories to be distinguished from AD. In most primary-care settings, AD will be the most common etiologic
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2023, Archives of Physical Medicine and RehabilitationBRAIM: A computer-aided diagnosis system for neurodegenerative diseases and brain lesion monitoring from volumetric analyses
2017, Computer Methods and Programs in BiomedicineCitation Excerpt :Besides the physiological aging and natural cognitive decline, numerous diseases such as Parkinson disease, Multiple Sclerosis, and many common processes in the adult population (i.e. infections, neoplasms, systemic diseases, drug consumption, etc.) can adversely affect cognitive functions both acute or chronically [1,2]. Regardless etiology, in all cases an early diagnosis is crucial to proceed with appropriate therapeutic measures in order to improve patients quality of life and/or moderate the development of clinical complications [3–5]. In the clinical setting, recent studies have highlighted the relevance of performing volumetric measurements instead of the classical approach of qualitative analyses.
Early development of social deficits in APP and APP-PS1 mice
2012, Neurobiology of AgingCitation Excerpt :Hence, there is an increasing need to find additional behavioral markers of AD pathology, which may be more reliable and accurate in modeling the disease progression in genetic mouse models than the cognitive deficits (Chung and Cummings, 2000). In particular, identifying AD-like behavioral abnormalities already at the early stages of AD pathology, i.e., before extensive plaque deposition, is of critical importance for testing the efficacy of potential early pharmacological and nonpharmacological treatments (Knopman, 1998). For all these reasons, growing attention has recently been devoted to the noncognitive characterization of genetic mouse models of AD, focusing on those behavioral alterations which may parallel specific symptoms observed in AD patients.
New diagnoses of dementia among older patients admitted to postacute care
2010, Journal of the American Medical Directors AssociationCitation Excerpt :Interestingly, this association was not found in a study in assisted living facilities4 and has been inconsistently observed in studies conducted among community-dwelling and primary care older populations,8,11,12,27 but has also been reported in a study among acute medical inpatients.28 Most likely, underrecognition in the oldest-old patients relates to the still widespread belief of a normal age-related decline in mental performances.29 In addition, these patients might also be at increased risk for underrecognition because the usual barriers to diagnosis might seem especially relevant to physicians caring for these frail patients.
The geriatric assessment
2011, American Family Physician