Assessment of Mendelian and risk-factor genes in Alzheimer disease: A prospective nationwide clinical utility study and recommendations for genetic screening.

PURPOSE: To assess the likely pathogenic/pathogenic (LP/P) variants rates in Mendelian dementia genes and the moderate-to-strong risk factors rates in patients with Alzheimer disease (AD). METHODS: We included 700 patients in a prospective study and performed exome sequencing. A panel of 28 Mendelian and 6 risk-factor genes was interpreted and returned to patients. We built a framework for risk variant interpretation and risk gradation and assessed the detection rates among early-onset AD (EOAD, age of onset (AOO) ≤65 years, n = 608) depending on AOO and pedigree structure and late-onset AD (66 < AOO < 75, n = 92). RESULTS: Twenty-one patients carried a LP/P variant in a Mendelian gene (all with EOAD, 3.4%), 20 of 21 affected APP, PSEN1, or PSEN2. LP/P variant detection rates in EOAD ranged from 1.7% to 11.6% based on AOO and pedigree structure. Risk factors were found in 69.5% of the remaining 679 patients, including 83 (12.2%) being heterozygotes for rare risk variants, in decreasing order of frequency, in TREM2, ABCA7, ATP8B4, SORL1, and ABCA1, including 5 heterozygotes for multiple rare risk variants, suggesting non-monogenic inheritance, even in some autosomal-dominant-like pedigrees. CONCLUSION: We suggest that genetic screening should be proposed to all EOAD patients and should no longer be prioritized based on pedigree structure.

The relationship between semantic and episodic memory: evidence from a case of severe anterograde amnesia.

It is increasingly being recognized that new declarative, consciously accessible information can be learned in anterograde amnesia, but it is not clear whether this learning is supported by episodic or semantic memory. We report a case of a 55-year-old man who experienced severe amnesia after limited damage to the medial temporal lobe following neurosurgical complications. His general cognitive performance and knowledge of new French words and public events that occurred before and after the onset of amnesia were assessed. Performance remained satisfactory on post-morbid vocabulary and public events, with a drop in performance observed for very recent public events only, while knowledge of very recent vocabulary was comparable to that of the control subjects. The implications of these findings for our understanding of the underlying learning mechanisms are discussed. This is the first report of acquisition of consciously accessible postmorbid knowledge of public events in a patient with severe amnesia.

Empowering general practitioners in dementia care: The ANTISTIGMA education intervention in Europe.

BACKGROUND: There is a well-documented lack or delay of diagnosis of dementia in all countries, including in Europe. Most general practitioners (GPs) have acquired adequate academic and scientific information about dementia but avoid using it in practice because of stigma. OBJECTIVES: To persuade GPs of their role in dementia detection, an Antistigma education intervention was designed, with teaching objectives focusing on "Why" and "How" to diagnosis and manage dementia, based on ethical and practical content, as opposed to classical training centered on teaching "What", with mainly academic content. METHODS: During the European Joint Action "ACT ON DEMENTIA", the Antistigma education intervention was implemented in four Universities: Lyon and Limoges (France), Sofia (Bulgaria) and Lublin (Poland). General data, including information about training and experience in dementia, was collected. Specific scales measured Dementia Negative Stereotypes DNS and Dementia Clinical Confidence D-CO before and after training. RESULTS: 134 GPs and 58 residents R completed the training. The participants were mainly women (74%), and the mean age was 42.8 ± 13.2. Before training, participants expressed difficulties in defining GPs role and worries about inflicting Stigma, Risks of diagnosis, Lack of benefit and Communication difficulties. Participants' D-CO was significantly higher for Diagnosis process (64%) than for other clinical situations. After training, total NS was reduced from 34.2% to 29.9% (p < 0.001), and stereotypes were improved: GPs' role (40.1% reduced to 35.9%; p < 0.001), Stigma (38.7% reduced to 35.5%; p < 0.001), Risks of diagnosis (39.0% reduced to 33.3%; p < 0.001), Lack of Benefit (29.3% reduced to 24.6%; p < 0.001) and Communication difficulties (19.9% reduced to 16.9%; p < 0.001). After training, D-CO was significantly increased in all the clinical situations (p < 0.001), but stayed highest for Diagnosis Process. There was no significant difference between the universities. Participants who benefited best from the Antistigma education intervention were those without training in Geriatrics and those working in nursing homes (who reduced the most D-NS), as well younger participants and those who managed less than five people living with dementia per week (who increased the most D-CO). CONCLUSION: The Antistigma program is based on the idea that most often GPs and R have acquired adequate academic and scientific information about dementia but avoid using it in practice because of stigma. These results outline the importance of addressing ethical issues and practical management situations in dementia education, to empower GPs in dementia care.

Phenotype and imaging features associated with APP duplications.

BACKGROUND: APP duplication is a rare genetic cause of Alzheimer disease and cerebral amyloid angiopathy (CAA). We aimed to evaluate the phenotypes of APP duplications carriers. METHODS: Clinical, radiological, and neuropathological features of 43 APP duplication carriers from 24 French families were retrospectively analyzed, and MRI features and cerebrospinal fluid (CSF) biomarkers were compared to 40 APP-negative CAA controls. RESULTS: Major neurocognitive disorders were found in 90.2% symptomatic APP duplication carriers, with prominent behavioral impairment in 9.7%. Symptomatic intracerebral hemorrhages were reported in 29.2% and seizures in 51.2%. CSF Aß42 levels were abnormal in 18/19 patients and 14/19 patients fulfilled MRI radiological criteria for CAA, while only 5 displayed no hemorrhagic features. We found no correlation between CAA radiological signs and duplication size. Compared to CAA controls, APP duplication carriers showed less disseminated cortical superficial siderosis (0% vs 37.5%, p = 0.004 adjusted for the delay between symptoms onset and MRI). Deep microbleeds were found in two APP duplication carriers. In addition to neurofibrillary tangles and senile plaques, CAA was diffuse and severe with thickening of leptomeningeal vessels in all 9 autopsies. Lewy bodies were found in substantia nigra, locus coeruleus, and cortical structures of 2/9 patients, and one presented vascular amyloid deposits in basal ganglia. DISCUSSION: Phenotypes associated with APP duplications were heterogeneous with different clinical presentations including dementia, hemorrhage, and seizure and different radiological presentations, even within families. No apparent correlation with duplication size was found. Amyloid burden was severe and widely extended to cerebral vessels as suggested by hemorrhagic features on MRI and neuropathological data, making APP duplication an interesting model of CAA.

Seizures in the elderly: development and validation of a diagnostic algorithm.

Seizures are frequent in the elderly, but their diagnosis can be challenging. The objective of this work was to develop and validate an expert-based algorithm for the diagnosis of seizures in elderly people. A multidisciplinary group of neurologists and geriatricians developed a diagnostic algorithm using a combination of selected clinical, electroencephalographical and radiological criteria. The algorithm was validated by multicentre retrospective analysis of data of patients referred for specific symptoms and classified by the experts as epileptic patients or not. The algorithm was applied to all the patients, and the diagnosis provided by the algorithm was compared to the clinical diagnosis of the experts. Twenty-nine clinical, electroencephalographical and radiological criteria were selected for the algorithm. According to criteria combination, seizures were classified in four levels of diagnosis: certain, highly probable, possible or improbable. To validate the algorithm, the medical records of 269 elderly patients were analyzed (138 with epileptic seizures, 131 with non-epileptic manifestations). Patients were mainly referred for a transient focal deficit (40%), confusion (38%), unconsciousness (27%). The algorithm best classified certain and probable seizures versus possible and improbable seizures, with 86.2% sensitivity and 67.2% specificity. Using logistical regression, 2 simplified models were developed, the first with 13 criteria (Se 85.5%, Sp 90.1%), and the second with 7 criteria only (Se 84.8%, Sp 88.6%). In conclusion, the present study validated the use of a revised diagnostic algorithm to help diagnosis epileptic seizures in the elderly. A prospective study is planned to further validate this algorithm.