ABSTRACT
Descriptions of dementia can be traced to antiquity. Prichard (1837) described four dementia stages and Kral (1962) described a "benign senescent forgetfulness" condition. The American Psychiatric Association's DSM-III (1980) identified an early dementia stage. In 1982, the Clinical Dementia Rating (CDR) and the Global Deterioration Scale (GDS) were published, which identified dementia antecedents. The CDR 0.5 "questionable dementia" stage encompasses both mild dementia and earlier antecedents. GDS stage 3 described a predementia condition termed "mild cognitive decline" or, alternatively, beginning in 1988, "mild cognitive impairment" (MCI). This GDS stage 3 MCI condition is differentiated from both a preceding GDS stage 2, "subjective cognitive impairment" (SCI) stage and a subsequent GDS 4 stage of mild dementia.GDS stage 3 MCI has been well characterized. For example, specific clinical concomitants, mental status and psychological assessment score ranges, behavioral and emotional changes, neuroimaging concomitants, neurological reflex changes, electrophysiological changes, motor and coordination changes, and changes in activities, accompanying GDS stage 3 MCI have been described.Petersen and associates proposed a definition of MCI in 2001 which has been widely used (hereafter referred to as "Petersen's MCI"). Important differences between GDS stage 3 MCI and Petersen's MCI are that, because of denial, GDS stage 3 MCI does not require memory complaints. Also, GDS stage 3 MCI recognizes the occurrence of executive level functional deficits, which Petersen's MCI did not. Nevertheless, longitudinal and other studies indicate essential compatibility between GDS stage 3 MCI and Petersen's MCI duration and outcomes.
Subject(s)
Alzheimer Disease/diagnosis , Cognition Disorders/diagnosis , Aged , Alzheimer Disease/drug therapy , Alzheimer Disease/history , Cognition Disorders/drug therapy , Cognition Disorders/history , Diagnostic and Statistical Manual of Mental Disorders , Disease Progression , History, 19th Century , History, 20th Century , History, Ancient , Humans , Memory Disorders/diagnosis , Memory Disorders/drug therapy , Memory Disorders/psychology , Psychiatric Status Rating Scales/statistics & numerical data , Severity of Illness Index , Terminology as TopicABSTRACT
Cerebrovascular small vessel disease is now believed to be the major source of vascular burden of the brain. Cerebrovascular small vessel disease and Alzheimer's disease appear to represent pathophysiologic and clinical continua, rather than dichotomous entities. It appears that common etiopathologic mechanisms underlie the clinical presentation of both of these conditions. Therefore, the staging procedures that have been developed for the clinical continuum of age-associated memory impairment, mild cognitive impairment, and the progressive dementia of Alzheimer's disease appear to be applicable for the same continua in cerebrovascular small vessel disease. Although temporal and prognostic aspects have been studied for the Alzheimer's-related portions of this clinical staging continuum, they remain to be elucidated for cerebrovascular small vessel disease.
Subject(s)
Alzheimer Disease/epidemiology , Alzheimer Disease/physiopathology , Brain/blood supply , Brain/physiopathology , Cerebrovascular Disorders/epidemiology , Cost of Illness , Aged , Alzheimer Disease/metabolism , Cerebrovascular Circulation , Cognition Disorders/diagnosis , Follow-Up Studies , Humans , Neuropsychological Tests , Prospective Studies , Severity of Illness Index , Vitamin B 12/metabolismABSTRACT
Retrogenesis is the process by which degenerative mechanisms reverse the order of acquisition in normal development. Alzheimer's disease (AD) and related conditions in the senium have long been noted to resemble "a return to childhood" Previously, we noted that the functional stages of AD precisely and remarkably recapitulated the acquisition of the same functional landmarks in normal human development. Subsequent work indicated that this developmental recapitulation also applied to the cognitive and related symptoms in AD. Remarkably, further investigations revealed that the same neurologic "infantile" reflexes, which mark the emergence from infancy in normal development, are equally robust indicators of corresponding stages in AD. Neuropathologic and biomolecular mechanisms for these retrogenic processes are now evident. For example, the pattern of myelin loss in AD appears to mirror the pattern of myelin acquisition in normal development. Also, recent findings indicate that mitogenic factors become reactivated in AD, and, consequently, the most actively "growing" brain regions are the most vulnerable. Because of this robust retrogenic process, the stages of AD can be translated into corresponding developmental ages (DAs). These DAs can account for the overall management and care needs of AD patients. A science of AD management can be formulated on the basis of the DA of the Alzheimer's patient, taking into consideration differences of AD from normal development as well as homologies.
