α-Synuclein seeding activity in duodenum biopsies from Parkinson's disease patients.

Abnormal deposition of α-synuclein is a key feature and biomarker of Parkinson's disease. α-Synuclein aggregates can propagate themselves by a prion-like seeding-based mechanism within and between tissues and are hypothesized to move between the intestine and brain. α-Synuclein RT-QuIC seed amplification assays have detected Parkinson's-associated α-synuclein in multiple biospecimens including post-mortem colon samples. Here we show intra vitam detection of seeds in duodenum biopsies from 22/23 Parkinson's patients, but not in 6 healthy controls by RT-QuICR. In contrast, no tau seeding activity was detected in any of the biopsies. Our seed amplifications provide evidence that the upper intestine contains a form(s) of α-synuclein with self-propagating activity. The diagnostic sensitivity and specificity for PD in this biopsy panel were 95.7% and 100% respectively. End-point dilution analysis indicated up to 106 SD50 seeding units per mg of tissue with positivity in two contemporaneous biopsies from individual patients suggesting widespread distribution within the superior and descending parts of duodenum. Our detection of α-synuclein seeding activity in duodenum biopsies of Parkinson's disease patients suggests not only that such analyses may be useful in ante-mortem diagnosis, but also that the duodenum may be a source or a destination for pathological, self-propagating α-synuclein assemblies.

Does epilepsy contribute to the clinical phenotype of C9orf72 mutation in fronto-temporal dementia?

C9orf72 mutation is the most common genetic cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) worldwide. Recently, several reports of patients with FTD who carried the C9orf72 mutation and also manifested epilepsy have been published, since seizures occur in FTD at a higher rate than in the general population, the possible association between epilepsy and C9orf72 mutation remains to be clarified. In the attempt to understand whether epilepsy contributes to the phenotype of the C9orf72 mutation, we compared epilepsy occurrence in patients with FTD who carried the C9orf72 mutation and those who did not. In our sample of 84 patients with FTD, 7.1% of cases reported epilepsy, with no significant differences between subsamples of patients with FTD stratified according to the presence of the C9orf72 mutation or to family history of FTD/parkinsonism/motor neuron disease. Our findings did not support to the possibility that epilepsy represents a characteristic feature of the C9orf72 mutation, as suggested by recent case reports published in the English literature.

Incidence and spatial distribution of adult-onset primary malignant and other central nervous system tumors in Southern Sardinia, Italy.

PURPOSE: To study for the first time the incidence of adult-onset CNS tumors in Southern Sardinia, Italy. METHODS: Clinical records of patients > 18 years old who were diagnosed with primary CNS tumors during 2016-2019 in the study area were reviewed. Meningiomas, cranial/paraspinal nerve tumors, lymphomas, and pituitary tumors were excluded. Cases were classified according to the 2016 WHO classification of CNS tumors and to the morphology codes from the International Classification of Diseases-Oncology, third edition. Age-adjusted incidence rates were calculated by the direct method to the 2011-2020 European standard population. Kulldorff's spatial scan statistic was used to identify geographic clusters of patients who shared increased/decreased tendency to develop CNS tumors. RESULTS: CNS tumors were diagnosed in 234 incident patients, but histological diagnosis was available in 222/234 patients (95%) aged 64.3 ± 13.5 years at diagnosis. Crude incidence rate was 7.1 per 100,000 persons-year (95% CI, 6.2-8.1), 6.2 per 100,000 persons-year (95% CI, 5.4-7.0) when age-adjusted. CNS tumors were more frequent in men and after age 40. Glioblastoma accounted for 76% of the total (adjusted rate, 4.7 per 100,000 persons-year; 95% CI, 4.0-5.4). Spatial analysis revealed geographic variations of glioblastoma incidence within the study area. CONCLUSION: Although the distribution of tumor diagnoses in Sardinia reflects expected age and gender-related patterns in western populations, our findings would indicate a slightly higher incidence of glial tumors, glioblastoma in particular, in Sardinia than in other European countries. The identification of spatial clusters of high/low risk will serve as a resource for etiological research.