Retrograde and semantic amnesia in a case of post-treatment Lyme disease syndrome: did something lead to a psychogenic memory loss? A single-case study.

OBJECTIVE: To describe a case of Post-Treatment Lyme Disease Syndrome (PTLDS) with an atypical cognitive profile. METHOD: A 41-year-old PTLDS patient underwent comprehensive neuropsychological testing and psychological assessment. RESULTS: The patient exhibited impaired intensive attention but preserved selective attention. Executive functions were normal. Short-term and anterograde memory were intact, while retrograde and semantic memory were significantly impaired. The patient also experienced identity loss, specific phobias, dissociative symptoms, and depressed mood. CONCLUSIONS: Severe episodic-autobiographical and retrograde semantic amnesia was consistent with some reports of dissociative amnesia. Loss of identity and phobias were also highly suggestive of a psychogenic mechanism underlying amnesia.

Occipital atrophy signature in prodromal Lewy bodies disease.

INTRODUCTION: Dementia with Lewy bodies (DLB) is typically characterized by parietal, temporal, and occipital atrophy, but less is known about the newly defined prodromal phases. The objective of this study was to evaluate structural brain alterations in prodromal DLB (p-DLB) as compared to healthy controls (HC) and full-blown dementia (DLB-DEM). METHODS: The study included 42 DLB patients (n = 20 p-DLB; n = 22 DLB-DEM) and 27 HC with a standardized neurological assessment and 3-tesla magnetic resonance imaging. Voxel-wise analyses on gray-matter and cortical thickness were implemented to evaluate differences between p-DLB, DLB-DEM, and HC. RESULTS: p-DLB and DLB-DEM exhibited reduced occipital and posterior parieto-temporal volume and thickness, extending from prodromal to dementia stages. Occipital atrophy was more sensitive than insular atrophy in differentiating p-DLB and HC. Occipital atrophy correlated to frontotemporal structural damage increasing from p-DLB to DLB-DEM. DISCUSSION: Occipital and posterior-temporal structural alterations are an early signature of the DLB continuum and correlate with a long-distance pattern of atrophy.

CSF alpha-synuclein aggregates by seed amplification and clinical presentation of AD.

INTRODUCTION: Accumulating evidence suggests that α-synuclein (αSyn) can modulate Alzheimer's disease (AD) pathology. The aim of this study was to evaluate the prevalence and clinical features associated with cerebrospinal fluid (CSF) αSyn detected by seed amplification assay (SAA) in AD. METHODS: Eighty AD patients with CSF AT(N) biomarker positivity (mean age 70.3 ± 7.3 years) and 28 non-AD age-matched controls were included. All subjects underwent standardized clinical assessment; CSF αSyn aggregates were detected by SAA. RESULTS: CSF was αSyn-SAA positive (αSyn+) in 36/80 AD patients (45%) and in 2/28 controls (7.1%). AD αSyn+ and αSyn- patients were comparable for age, disease severity, comorbidity profile, and CSF core biomarkers. AD αSyn+ presented a higher prevalence of atypical phenotypes and symptoms. CONCLUSIONS: Our findings demonstrate that concomitant CSF αSyn pathology is present in a significant proportion of AD patients starting in the early stages and can affect clinical presentation. Longitudinal studies are warranted to evaluate the significance for the disease course.

Face and emotional expression processing under continuous perceptual load tasks: An ERP study.

High perceptual load is thought to impair already the early stages of visual processing of task-irrelevant visual stimuli. However, recent studies showed no effects of perceptual load on early ERPs in response to task-irrelevant emotional faces. In this preregistered EEG study (N = 40), we investigated the effects of continuous perceptual load on ERPs to fearful and neutral task-irrelevant faces and their phase-scrambled versions. Perceptual load did not modulate face or emotion effects for the P1 or N170. In contrast, larger face-scramble and fearful-neutral differentiation were found during low as compared to high load for the Early Posterior Negativity (EPN). Further, face-independent P1, but face-dependent N170 emotional modulations were observed. Taken together, our findings show that P1 and N170 face and emotional modulations are highly resistant to load manipulations, indicating a high degree of automaticity during this processing stage, whereas the EPN might represent a bottleneck in visual information processing.