Objectives: To estimate the lifetime risk, prevalence, incidence, and mortality of the principal clinical syndromes associated with frontotemporal lobar degeneration (FTLD) using revised diagnostic criteria and including intermediate clinical phenotypes.Methods: Multisource referral over 2 years to identify all diagnosed or suspected cases of frontotemporal dementia (FTD), progressive supranuclear palsy (PSP), or corticobasal syndrome (CBS) in 2 UK counties (population 1.69 million). Diagnostic confirmation used current consensus diagnostic criteria after interview and reexamination. Results were adjusted to the 2013 European standard population.Results: The prevalence of FTD, PSP, and CBS was 10.8/100,000. The incidence and mortality were very similar, at 1.61/100,000 and 1.56/100,000 person-years, respectively. The estimated lifetime risk is 1 in 742. Survival following diagnosis varied widely: from PSP 2.9 years to semantic variant FTD 9.1 years. Age-adjusted prevalence peaked between 65 and 69 years at 42.6/100,000: the age-adjusted prevalence for persons older than 65 years is double the prevalence for those between 40 and 64 years. Fifteen percent of those screened had a relevant genetic mutation.Conclusions: Key features of this study include the revised diagnostic criteria with improved specificity and sensitivity, an unrestricted age range, and simultaneous assessment of multiple FTLD syndromes. The prevalence of FTD, PSP, and CBS increases beyond 65 years, with frequent genetic causes. The time from onset to diagnosis and from diagnosis to death varies widely among syndromes, emphasizing the challenge and importance of accurate and timely diagnosis. A high index of suspicion for FTLD syndromes is required by clinicians, even for older patients.Neurology ® 2016;86:1736-1743 GLOSSARY bvFTD 5 behavioral variant frontotemporal dementia; CBS 5 corticobasal syndrome; ESP2013 5 European Standard Population 2013; FTD 5 frontotemporal dementia; FTLD 5 frontotemporal lobar degeneration; MND 5 motor neuron disease; nfvPPA 5 nonfluent agrammatic variant primary progressive aphasia; PiPPIN 5 Pick's Disease and Progressive Supranuclear Palsy: Prevalence and Incidence; PPA 5 primary progressive aphasia; PSP 5 progressive supranuclear palsy; svPPA 5 semantic variant primary progressive aphasia.Frontotemporal lobar degeneration (FTLD) causes diverse clinical syndromes including behavioral variant frontotemporal dementia (bvFTD), with or without motor neuron disease (MND); primary progressive aphasias (PPAs) (semantic variant [svPPA], nonfluent agrammatic variant [nfvPPA], and logopenic variant); progressive supranuclear palsy (PSP) (Steele-RichardsonOlszewski syndrome); and the corticobasal syndrome (CBS). These syndromes are common causes of young-onset dementia, 1,2 but there are potential limitations to previous estimates of prevalence and incidence. First, the diagnostic criteria have been revised significantly in recent years [3][4][5][6] with changes in specificity and sensitivity. 4 For example, many pat...
Newcastle disease virus (NDV) strains, isolated from outbreaks during epizootics between 1992 and 1996 in Western European countries, were compared by restriction enzyme cleavage site mapping of the fusion (F) protein gene between nucleotides 334 and 1682 and by sequence analysis between nucleotides 47 and 435. Both methods revealed that NDV strains responsible for these epizootics belong to two distinct genotypes. Strains derived from sporadic cases in Denmark, Sweden, Switzerland and Austria were classified into genotype VI [6], the same group which caused outbreaks in the Middle East and Greece in the late 1960's and in Hungary in the early 1980's. In contrast, viruses that caused epizootics in Germany, Belgium, The Netherlands, Spain and Italy could be classified into a novel genotype (provisionally termed VII), hitherto undetected in Europe. It is possible that the genotype VII viruses originated in the Far East because they showed a high genetic similarity (97%) to NDV strains isolated from Indonesia in the late 1980's.
34 strains of Newcastle disease virus (NDV) isolated during epizootics in the Republic of South Africa and in Mozambique between 1990 and 1995, and in Bulgaria and Turkey in 1995-1997 were identified by restriction enzyme and partial sequence analysis of the fusion (F) protein gene. The majority of isolates in southern Africa and those from Bulgaria and Turkey were placed into a novel group which has been termed VIIb. Group VIIb is part of a larger genetic cluster (VII) that also includes NDV strains from the Far East and some western European countries (VIIa). The genetic distance of 7-8, 5% between genotype VIIa and VIIb viruses excludes the existence of a direct epidemiological link between recent southern African epizootics and outbreaks in either western Europe in the 1990's or those of the Far East. Another hitherto unrecorded genotype (VIII) was also found in South Africa with descendants of putative ancestral members isolated in the 1960's. The genetic distance of recent group VIII strains from the major epizootic genotype (VIIb) is over 11%, therefore outbreaks caused by them were epidemiologically unrelated. Genotype VIII viruses must have been maintained in South Africa by endemic infections during the past decades while group VIIb appears to be introduced more recently.
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