Aging, Memory, and Mild Cognitive Impairment

Abstract

In recent years, patients who are at high risk for developing Alzheimer's disease (AD) have become a focus of study. Several research groups have identified these patients, developed diagnostic criteria, and followed the patients longitudinally. These patients therefore constitute a clinical entity that is suitable for therapeutic interventions. In this article, we report our 5-year experience at the Mayo Clinic in characterizing a group of patients with mild cognitive impairment. These subjects were recruited from community-dwelling individuals who were receiving general medical care in the Department of Internal Medicine. They received the diagnosis of mild cognitive impairment if they met the following criteria: (a) complaint of defective memory, (b) normal activities of daily living, (c) normal general cognitive function, (d) abnormal memory function for age, and (e) absence of dementia. In following more than 75 of these patients, some of whom have been studied for as long as 5 years, it appears that approximately 10% to 15% of the subjects evolve to AD each year. We therefore evaluated the cognitive profiles of these patients at the time of their initial diagnosis in an attempt to predict who would remain stable and who would evolve to AD. Certain features of learning and memory performance indicated patients who were more likely to progress, but the strongest predictor was their apolipoprotein E status. The patients who possessed an ε4 allele were more likely to convert to AD at a more rapid rate then those who were not carriers. Our results and similar data from other study groups indicate that diagnostic criteria can be defined for patients who are likely to convert to AD; the natural history of these patients is becoming apparent, and variables that predict ultimate conversion can be defined. Consequently, patients with mild cognitive impairment constitute an important group for study, particularly from the aspect of therapeutic interventions.

Mind the gaps—advancing research into short-term and long-term neuropsychological outcomes of youth sports-related concussions

“…85,86 Alternatively, CNI may represent static impairment without degeneration. Our current lack of understanding of the basic biological underpinnings of CNI and CTE underscores the need for more research.…”

Vascular damage and EEG markers in subjects with mild cognitive impairment

“…Our inclusion and exclusion criteria for MCI were based on previous seminal studies (Albert et al, 1991;Devanand et al, 1997;Flicker et al, 1991;Petersen et al, 1995Petersen et al, , 1997Petersen et al, , 2001Portet et al, 2006;Geroldi et al, 2006). Study inclusion criteria were all of the following: (i) complaint by the patient, or report by a relative or the general practitioner, of memory or other cognitive disturbances; (ii) Mini-Mental State Examination (MMSE; Folstein et al, 1975) score of 24 to 27/30, or MMSE of 28 and higher plus low performance (score of 2/6 or higher) on the clock drawing test (Shulman, 2000); (iii) sparing of instrumental and basic activities of daily living, or functional impairment stably due to causes other than cognitive impairment, such as physical impairments, sensory loss, gait or balance disturbances, etc.…”

Age-dependent loss of NGF signaling in the rat basal forebrain is due to disrupted MAPK activation

“…One challenge in this endeavor is the paucity of diagnostic criteria that separate AD from other forms of dementia, and definite diagnosis thus occurs at the time of autopsy. One potential method of identifying early AD is identifying and tracking patients with MCI [11,27,31,[39][40][41]. Many of the hallmarks of AD, such as elevated beta amyloid levels, amyloid plaques, and hyperphosphorylated tau do not correlate well with cognitive decline [3,4].…”