Background: D. Frank Benson and colleagues first described the clinical and neuropathological features of posterior cortical atrophy (PCA) from patients in the UCLA Neurobehavior Program. Objective: We reviewed the Program’s subsequent clinical experience with PCA, and its potential for clarifying this relatively rare syndrome in comparison to the accumulated literature on PCA. Methods: Using the original criteria derived from this clinic, 65 patients with neuroimaging-supported PCA were diagnosed between 1995 and 2020. Results: On presentation, most have visual localization complaints and related visuospatial symptoms, but nearly half had memory complaints followed by symptoms of depression. Neurobehavioral testing showed predominant difficulty with visuospatial constructions, Gerstmann’s syndrome, and Balint’s syndrome, but also impaired memory and naming. On retrospective application of the current Consensus Criteria for PCA, 59 (91%) met PCA criteria with a modification allowing for “significantly greater visuospatial over memory and naming deficits.” There were 37 deaths (56.9%) with the median overall survival of 10.3 years (95% CI: 9.6–13.6 years), consistent with a slow neurodegenerative disorder in most patients. Conclusion: Together, these findings recommend modifying the PCA criteria for “relatively spared” memory, language, and behavior to include secondary memory and naming difficulty and depression, with increased emphasis on the presence of Gerstmann’s and Balint’s syndromes.

Background: Semantic dementia (SD) is characterized by progressive semantic anomia extending to a multimodal loss of semantic knowledge. Although often considered an early-onset dementia, SD also occurs in later life, when it may be misdiagnosed as Alzheimer disease (AD). Objective: To evaluate late-onset SD in comparison to early-onset SD and to AD. Methods: We identified 74 individuals with SD and then compared those with late-onset SD (≥65 years of age) to those with early-onset SD (<65) on demographic and clinical features. We also compared a subgroup of 23 of the late-onset SD individuals with an equal number of individuals with clinically probable AD. Results: Twenty-six (35.1%) of the SD individuals were late onset, and 48 (64.9%) were early onset. There were no differences between the two groups on clinical measures, although greater asymmetry of temporal involvement trended to significance in the late-onset SD group. Compared to the 23 AD individuals, the subgroup of 23 late-onset SD individuals had worse performance on confrontational naming, irregular word reading, and face recognition; however, this subgroup displayed better verbal delayed recall and constructions. The late-onset SD individuals also experienced early personality changes at a time when most individuals with AD had not yet developed behavioral changes. Conclusions: Approximately one-third of SD individuals may be late onset, and the differentiation of late-onset SD from AD can lead to better disease management, education, and prognosis. SD may be distinguished by screening for disproportionate changes in reading, face recognition, and personality.

The experience of embarrassment signals violations in social norms, and impairment in this social emotion may underlie much of the social dysfunction in behavioral variant frontotemporal dementia (bvFTD). The authors investigated whether impaired self-awareness of embarrassment may distinguish patients with bvFTD early in the course of disease from healthy control subjects (HCs). Methods: Self-reported embarrassment was examined among 18 patients with early bvFTD and 23 HCs by using the 36-item Embarrassability Scale, which includes items of situations eliciting embarrassment for oneself ("selfembarrassment") and embarrassment for others ("vicarious embarrassment"). The two study groups were also compared with the Social Norms Questionnaire (SNQ). The analyses included correlations of SNQ results (total score, violations or "break" errors, and overendorsement of social rules or "overadhere" errors) with Embarrassability Scale scores.Results: Patients with bvFTD did not differ from HCs on total or self-embarrassment scores but did have significantly higher vicarious embarrassment scores. Unlike in the HC group, reports of vicarious embarrassment did not differ from reports of self-embarrassment among patients in the bvFTD group. The Embarrassability Score further correlated with overadherence to norms on the SNQ.Conclusions: In the presence of social dysfunction and emotional blunting, these findings suggest that patients with bvFTD rely on their own perspective for a rule-based application of social norms in reporting vicarious embarrassment. The assessment of reports of embarrassment for others may indicate an early and previously unrecognized clinical measure for detecting bvFTD.

Background: Neuropsychiatric symptoms can impact decision-making in patients with Alzheimer disease (AD). Methods: Using a simple decision-making task, a variant of the ultimatum game (UG) modified to control feelings of unfairness, this study investigated rejection responses among responders to unfair offers. The UG was administered to 11 patients with AD, 10 comparably demented patients with behavioral variant frontotemporal dementia (bvFTD), and 9 healthy controls (HC). The results were further compared with differences on the caregiver Neuropsychiatric Inventory (NPI). Results: Overall, patients with AD significantly rejected more total offers than did the patients with bvFTD and the HC ( P < .01). On the NPI, the only domain that was significantly worse among the patients with AD compared to the other groups was dysphoria/depression. Conclusions: These results suggest that early AD can be distinguished based on increased rejections of offers in decision-making, possibly consequent to a heightened sense of unfairness from dysphoria/depression.