Alex Rajput

BACKGROUND: PSP is a neuropathologically defined disease entity. Clinical diagnostic criteria, published in 1996 by the National Institute of Neurological Disorders and Stroke/Society for PSP, have excellent specificity, but their sensitivity is limited for variant PSP syndromes with presentations other than Richardson's syndrome. OBJECTIVE: We aimed to provide an evidence- and consensus-based revision of the clinical diagnostic criteria for PSP. METHODS: We searched the PubMed, Cochrane, Medline, and PSYCInfo databases for articles published in English since 1996, using postmortem diagnosis or highly specific clinical criteria as the diagnostic standard. Second, we generated retrospective standardized clinical data from patients with autopsy-confirmed PSP and control diseases. On this basis, diagnostic criteria were drafted, optimized in two modified Delphi evaluations, submitted to structured discussions with consensus procedures during a 2-day meeting, and refined in three further Delphi rounds. RESULTS: Defined clinical, imaging, laboratory, and genetic findings serve as mandatory basic features, mandatory exclusion criteria, or context-dependent exclusion criteria. We identified four functional domains (ocular motor dysfunction, postural instability, akinesia, and cognitive dysfunction) as clinical predictors of PSP. Within each of these domains, we propose three clinical features that contribute different levels of diagnostic certainty. Specific combinations of these features define the diagnostic criteria, stratified by three degrees of diagnostic certainty (probable PSP, possible PSP, and suggestive of PSP). Clinical clues and imaging findings represent supportive features. CONCLUSIONS: Here, we present new criteria aimed to optimize early, sensitive, and specific clinical diagnosis of PSP on the basis of currently available evidence. © 2017 International Parkinson and Movement Disorder Society.

BACKGROUND: Alpha-synuclein plays a central role in the pathophysiology of Parkinson's disease. Three missense mutations in SNCA, the gene encoding alpha-synuclein, as well as genomic multiplications have been identified as causes for autosomal-dominantly inherited Parkinsonism. METHODS: Here, we describe a novel missense mutation in exon 4 of SNCA encoding a H50Q substitution in a patient with dopa-responsive Parkinson's disease with a family history of parkinsonism and dementia. RESULTS: The variant was not observed in public databases or identified in unrelated subjects. CONCLUSIONS: The substitution's evolutionary conservation and protein modeling provide additional support for pathogenicity as the amino acid perturbs the same amphipathic alpha helical structure as the previously described pathogenic mutations.

Clinical diagnosis of Parkinson's syndrome (PS) is reasonably easy in most cases but the distinction between different variants of PS may be difficult in early cases. The correct diagnosis is not only important for counselling and management of patients but also in conducting pharmacological and epidemiological studies. There is very little critical literature on the pathological verification of the clinical diagnosis in PS. We report our 22 years experience to address that issue. Between 1968 and 1990, 65 PS patients came to autopsy. Complete data are available in 59 (M-50, F-19) cases. The initial diagnosis made by a qualified neurologist was idiopathic Parkinson's disease (IPD) in 43 cases. Of those 28 (65%) had Lewy body pathology. After a mean duration of 12 years the final diagnosis was IPD in 41 cases which was confirmed in 31 (76%). The IPD could not be clinically distinguished from cases with severe substantia nigra neuronal loss without inclusions or from those with neurofibrillary tangle inclusions and neuronal loss at the anatomical sites typically involved in IPD. All progressive supra-nuclear palsy, olivopontocerebellar atrophy, Jakob-Creutzfeldt's disease and the majority of the multiple system atrophy cases were diagnosed correctly during life. The correct clinical diagnosis in most non-IPD variants of PS was possible within 5 years of onset (range: 2 months to 18 years). We recommend that studies aimed at including only the IPD cases restrict the enrollment to those cases that have had PS motor manifestations for five years or longer duration.

A Saskatchewan multi-incident family was clinically characterized with Parkinson disease (PD) and Lewy body pathology. PD segregates as an autosomal-dominant trait, which could not be ascribed to any known mutation. DNA from three affected members was subjected to exome sequencing. Genome alignment, variant annotation and comparative analyses were used to identify shared coding mutations. Sanger sequencing was performed within the extended family and ethnically matched controls. Subsequent genotyping was performed in a multi-ethnic case-control series consisting of 2928 patients and 2676 control subjects from Canada, Norway, Taiwan, Tunisia, and the USA. A novel mutation in receptor-mediated endocytosis 8/RME-8 (DNAJC13 p.Asn855Ser) was found to segregate with disease. Screening of cases and controls identified four additional patients with the mutation, of which two had familial parkinsonism. All carriers shared an ancestral DNAJC13 p.Asn855Ser haplotype and claimed Dutch-German-Russian Mennonite heritage. DNAJC13 regulates the dynamics of clathrin coats on early endosomes. Cellular analysis shows that the mutation confers a toxic gain-of-function and impairs endosomal transport. DNAJC13 immunoreactivity was also noted within Lewy body inclusions. In late-onset disease which is most reminiscent of idiopathic PD subtle deficits in endosomal receptor-sorting/recycling are highlighted by the discovery of pathogenic mutations VPS35, LRRK2 and now DNAJC13. With this latest discovery, and from a neuronal perspective, a temporal and functional ecology is emerging that connects synaptic exo- and endocytosis, vesicular trafficking, endosomal recycling and the endo-lysosomal degradative pathway. Molecular deficits in these processes are genetically linked to the phenotypic spectrum of parkinsonism associated with Lewy body pathology.