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A critical memory skill rarely clinically tested is the ability to remember self-generated material. Healthy aged participants (n = 30; Experiment 1) and pilot participants with probable Alzheimer disease (pAD) (n = 9; Experiment 2) were twice administered a memory test including both internally generated and externally supplied items for recall. Healthy aged participants were biased to recall internally originating over externally supplied material on first, but not second, presentation. However, pAD participants demonstrated internal bias during both sessions. The pAD participants were also specifically impaired when told to remember internal material. This study provides further evidence that internally originating items can be used to assess memory. In pAD, memory for internal material with specific attempt to remember may be selectively impaired.

Patients who have the classic combination of progressive memory loss and problems retrieving stored knowledge that is characteristic of Alzheimer's disease may actually have another, treatable disorder. In these cases, appropriate evaluation can reveal the true diagnosis and guide therapy to stabilize or improve thinking and avert other complications. In this article, Dr Barrett explores 10 conditions that may be mistaken for Alzheimer's disease.

Objective: To develop a quantitative method of assessing cognitive anosognosia in six cognitive and two noncognitive domains., Methods: Control (n = 32) and probable Alzheimer disease (pAD) (n = 14) subjects self-estimated memory, attention, generative behavior, naming, visuospatial skill, limb praxis, mood, and uncorrected vision, both before and after these abilities were assessed. Based on this estimate and their performance the authors calculated an anosognosia ratio (AR) by dividing the difference between estimated and actual performance by an estimated and actual performance sum. With perfect awareness, AR = 0. Overestimating abilities would yield a positive AR (< or =1); underestimation would yield a negative AR (> or =-1)., Results: Relative to controls, pAD subjects demonstrated anosognosia. Pre-testing (off-line), pAD subjects overestimated their visuospatial skill; post-testing (on-line), pAD subjects overestimated their memory. Control subjects also made self-rating errors, underestimating their attention pre-testing and overestimating limb praxis and vision post-testing., Conclusions: This anosognosia assessment method may allow more detailed examination of distorted self-awareness. These results suggest that screening for anosognosia in probable Alzheimer disease (pAD) should include self-estimates of visuospatial function, and that, in pAD, it may be useful to assess anosognosia for amnesia both before and after memory testing.

Background: It remains unclear from lesion studies whether the four signs of the Gerstmann syndrome (finger agnosia, acalculia, agraphia, and right-left confusion) cluster because the neuronal nets that mediate these activities have anatomical proximity, or because these four functions share a common network. If there is a common network, with degeneration, as may occur in Alzheimer's disease, each of the signs associated with Gerstmann's syndrome should correlate with the other three signs more closely than they correlate with other cognitive deficits., Methods: Thirty eight patients with probable Alzheimer's disease were included in a retrospective analysis of neuropsychological functions., Results: The four Gerstmann's syndrome signs did not cluster together. Finger naming and calculations were not significantly correlated. Right-left knowledge and calculations also did not correlate., Conclusions: The four cognitive functions impaired in Gerstmann's syndrome do not share a common neuronal network, and their co-occurrence with dominant parietal lobe injuries may be related to the anatomical proximity of the different networks mediating these functions.

Objective: To learn how pAD (probable Alzheimer's disease), PD+ ("Parkinson's Plus" syndrome), and control subjects remember internally generated material under different conditions., Background: "Self-discovered," or internally generated knowledge, prized by educators and therapists, can bring about considerable behavioral change. Both parietal-temporal-limbic (pAD) and frontal-subcortical dementia (e.g. PD+) cause dysmemory, but may cause different internal-external memory bias. pAD subjects, confusing internal and external information (confabulation) and reporting internal information during memory testing (intrusions), may be biased to remember internal material. PD+ subjects, impaired at generative tests, may be externally biased., Methods: Ten pAD, 5 PD+, and 10 control subjects generated words in a category without instruction to remember (INR), and took a list-learning test of incidental memory for internally and externally generated words. To test how INR influences memory, subjects then generated and attempted to recall four more words., Results: All three subject groups remembered more internally generated than externally provided words without INR. Recall versus recognition of internally generated words differed by group, with PD+ subjects showing greatest improvement with recognition. The pAD subjects performed worse with INR than without INR, had the most intrusion errors, and, rather than demonstrating a release from proactive inhibition, recalled fewer words outside the category. Groups differed in overall recall/recognition improvement (p = 0.015)., Conclusions: Aged subjects preferentially retained internally generated material. However, among demented subjects, memory for internally generated words was influenced by the testing method used. PD+ subjects have poor internal recall, but excellent internal recognition. In pAD, memory for internally generated words may exceed external memory, but only when subjects are not explicitly trying to remember.

Probable Alzheimer's disease is diagnosed by exclusion when no other disorder--such as stroke, brain infection, or vitamin deficiency--can be found to account for specific cognitive change. Although probable Alzheimer's disease affects both men and women, studies in many different populations show that between 1.5 and 3 times as many women as men suffer from probable Alzheimer's disease. For women with the disease, one needs to consider behavioral and cognitive problems, therapeutic issues, and other gender-related risks. Additionally, social, psychological, and emotional variables play a role in the female caregiver's burden.