Signs and symptoms method in neuropsychology: A standardized observational examination of cognitive functions can be effective in detecting mild cognitive impairment.

OBJECTIVE: The present study aimed at investigating the sensitivity and specificity of the NeuroPsychological Examination (NPE), a systematic collection of cognitive signs and symptoms based on the observation of the patient's behavior during a clinical interview, in detecting Mild Cognitive Impairment (MCI). METHOD: 475 participants, 208 suffering from MCI, 188 suffering from dementia and 79 subjective cognitive decline (SCD), have been assessed using NPE for the presence of signs and symptoms of cognitive impairment. Receiver operating characteristic (ROC) curve analysis and the Youden's test were used to determine the more appropriate cutoff points for the number of neuropsychological signs at the NPE that enabled to discriminate SCD from MCI, SCD from dementia and MCI from dementia. A sensitivity and specificity analysis and comparisons among the three groups were conducted. RESULTS: The mean number of signs at the NPE were 1.73 for SCD, 7.98 for MCI and 12.82 for dementia. Pairwise comparisons among the three group of participants showed significant differences (SCD vs. MCI, p < .001, r = -0.66; SCD vs. dementia, p < .001, r = -0.76; MCI vs. dementia, p < .001, r = -0.44). The criterion of 3 signs at the NPE showed a sensitivity of 0.95 (95% CI [0.91, 0.97]) and a specificity of 0.76 (95% CI [0.65, 0.84]) in discriminating SCD from MCI participants. CONCLUSIONS: A signs and symptoms approach could be a useful tool for clinical neuropsychologists working in the field of MCI and dementia assessment. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Diencephalic versus Hippocampal Amnesia in Alzheimer's Disease: The Possible Confabulation-Misidentification Phenotype.

BACKGROUND: Alzheimer's disease (AD) is clinically heterogeneous, including the classical-amnesic (CA-) phenotype and some variants. OBJECTIVE: We aim to describe a further presentation we (re)named confabulation-misidentification (CM-) phenotype. METHODS: We performed a retrospective longitudinal case-series study of 17 AD outpatients with the possible CM-phenotype (CM-ADs). Then, in a cross-sectional study, we compared the CM-ADs to a sample of 30 AD patients with the CA-phenotype (CA-ADs). The primary outcome was the frequency of cognitive and behavioral features. Data were analyzed as differences in percentage by non-parametric Chi Square and mean differences by parametric T-test. RESULTS: Anterograde amnesia (100%) with early confabulation (88.2%), disorientation (88.2%) and non-infrequently retrograde amnesia (64.7%) associated with reduced insight (88.2%), moderate prefrontal executive impairment (94.1%) and attention deficits (82.3%) dominated the CM-phenotype. Neuropsychiatric features with striking misidentification (52.9%), other less-structured delusions (70.6%), and brief hallucinations (64.7%) were present. Marked behavioral disturbances were present early in some patients and very common at later stages. At the baseline, the CM-ADs showed more confabulation (p < 0.001), temporal disorientation (p < 0.02), misidentification (p = 0.013), other delusions (p = 0.002), and logorrhea (p = 0.004) than the CA-ADs. In addition, more social disinhibition (p = 0.018), reduction of insight (p = 0.029), and hallucination (p = 0.03) persisted at 12 months from baseline. Both the CA- and CM-ADs showed anterior and medial temporal atrophy. Compared to HCs, the CM-ADs showed more right fronto-insular atrophy, while the CA-ADs showed more dorsal parietal, precuneus, and right parietal atrophy. CONCLUSION: We described an AD phenotype resembling diencephalic rather than hippocampal amnesia and overlapping the past-century description of presbyophrenia.