Background: The Mild Behavioral Impairment Checklist (MBI-C), a screening scale for neuropsychiatric symptom evaluation, facilitates Alzheimer's disease (AD) screening. However, its validity and reliability for use as an AD screening tool have not been determined. Objective: To develop an AD screening scale suitable for the Chinese population. Methods: The MBI-C was translated into Chinese and back-translated with the original author's consent. Forty-six AD patients, attending the Xuanwu hospital memory clinic, and 50 sex-and education-matched controls from the community underwent a full neuropsychological evaluation, including MBI-C assessment. Among them, 15 AD patients were evaluated repeatedly, and eight were evaluated simultaneously by two different clinicians, to assess MBI-C reliability. Results:The MBI-C demonstrated good internal consistency reliability, test-retest reliability, and inter-rater reliability. Its optimal cutoff point was 6/7 for identifying AD dementia, with a sensitivity of 86.96% and specificity of 86.00%, and its detection rate for moderate-severe AD dementia was higher than that of the Neuropsychiatric Inventory Questionnaire (NPI-Q). Pearson's correlation coefficients ranged from 0.702 to 0.831, indicating content validity. Seven factors were extracted during principal component analysis, with a cumulative contribution of 70.55%. Moreover, the Pearson's correlation coefficient was 0.758, indicating its criterion validity. The MBI-C could also distinguish AD dementia severity. MBI-C scores were significantly negatively correlated with MMSE and MoCA scores, and positively correlated with ADL scores. Conclusion:This study showed that the Chinese version of MBI-C has high reliability and validity, and could replace the NPI-Q for AD dementia screening in the Chinese population.

BackgroundBehavioral variant frontotemporal dementia (bvFTD) is a clinically heterogeneous syndrome with high heredity. However, the frequencies of mutations associated with bvFTD have yet to be determined. The aim of the current study was to investigate the frequency of Chinese Han patients harboring genetic bvFTD variants.MethodsA total of 49 bvFTD patients selected from our frontotemporal lobar degeneration database, including 14 familial cases belonging to eight families and 35 sporadic cases were consecutively recruited from July 2014 to December 2019 at Xuanwu Hospital (Beijing, China). Whole-exome sequencing (WES) was performed and repeat-primed PCR was used to test samples for the C9orf72 hexanucleotide repeat expansion mutation. The frequency of genetic variants and the pathogenicity of the novel variants were analyzed.ResultsTen pathogenic or likely pathogenic variants were identified in 17 bvFTD patients, including C9orf72 repeat expansions, six previously reported mutations and three novel mutations (MAPT p. R5C, p. D54N, GRN p. P451L). Genetic mutations accounted for 27.9% (12/43) of total cases, 87.5% (7/8) of patients with familial bvFTD, and 14.3% (5/35) with sporadic bvFTD. Pathogenic variants mostly occurred in MAPT gene (20.9%, 9/43), followed by C9orf72 repeat expansions (2.3%, 1/43), GRN gene (2.3%, 1/43) and FUS gene (2.3%, 1/43).ConclusionThere was a high prevalence of genetic variants in Chinese bvFTD patients, highlighting the necessity of genetic testing for bvFTD.

Background: Pathologic processes in Creutzfeldt-Jakob disease (CJD) are not fully understood. Familial CJD (fCJD) gives opportunities to discover pathologic changes in the preclinical stage. Objective: To investigate cerebral glucose metabolism in the preclinical stage via 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in fCJD. Methods: Seven asymptomatic carriers of G114V mutation and six family members without PRNP mutation from the same fCJD kindred were included, and were followed for 2 years. Ten symptomatic CJD patients were also recruited. All subjects underwent standardized clinical examinations and 18F-FDG PET scans. Results were compared in three groups: baseline carriers against non-carriers (baseline analysis), changes after 2 years in carriers (follow-up analysis), and differences between symptomatic CJD patients and healthy controls (CJD patients analysis). Results: No carriers developed any neurological symptoms during 2-year follow-up. Baseline analysis: carriers demonstrates decreased metabolism (p < 0.001) in left and right postcentral, left fusiform, left superior temporal, left lingual, left superior parietal, and left Heschl gyrus. Follow-up analysis shows metabolic decline (p < 0.001) in right inferior temporal, left supra-marginal and left postcentral lobe, and increased metabolism (p < 0.001) in left fusiform, left angular, left thalamus, left Heschl’s, right Rolandic operculum, and left superior parietal gyrus. CJD patients demonstrates decreased metabolism in right inferior triangularis frontal gyrus, right middle occipital gyrus, right putamen, right thalamus, and right middle temporal gyrus. Conclusion: Hypo-metabolism of parietal and temporal lobe can be detected by 18F-FDG PET in the preclinical stage of CJD. Subcortical area might compensate in the preclinical stage and decompensate in the symptomatic stage.

For early-onset Alzheimer's disease (EOAD) cases with unclear family history, most cases are sporadic. Some cases are positive in genetic findings, that is, either incomplete penetrance or de novo mutation. We aimed to focus on EOAD cases with de novo mutations. Case reports and literature review were performed. The implication for diagnostic approach of early-onset dementia with negative family history was developed. We reported two Chinese EOAD cases with de novo mutations. The genotype PSEN1 G206S appeared to correlate with the phenotype of EOAD with pure cognitive problems. The second case had a PSEN1 M233V mutation with an earlier age of onset of 25 with cognitive decline, parkinsonism, and epilepsy. Although EOAD due to de novo mutations is not common, it should be considered in patients with a phenotype of progressive cognitive decline and amyloid positivity on PET or CSF analysis.