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BackgroundCurrently available treatments for Parkinson’s disease (PD) do not slow clinical progression nor target alpha-synuclein, the main pathology associated with the disease.ObjectiveThe study objective was to evaluate the efficacy and safety of prasinezumab, a humanized monoclonal antibody that binds aggregated alpha-synuclein, in individuals with early PD. The study rationale, design, and baseline characteristics of enrolled subjects are presented here.MethodsThe PASADENA study is a multicenter, randomized, double-blind, placebo-controlled treatment study. Individuals with early PD, recruited across the US and Europe, received monthly intravenous doses of prasinezumab (1500 mg or 4500 mg) or placebo for a 52-week period (Part 1), followed by a 52-week extension (Part 2) in which all participants received active treatment. Key inclusion criteria were: aged 40–80 years; Hoehn & Yahr (H&Y) Stage I or II; time from diagnosis ≤2 years; having bradykinesia plus one other cardinal sign of PD (e.g. resting tremor, rigidity); DAT-SPECT imaging consistent with PD; and either treatment naïve or on a stable monoamine oxidase B (MAO-B) inhibitor dose. Study design assumptions for sample size and study duration were built using a patient cohort from the Parkinson’s Progression Marker Initiative (PPMI). In this report, baseline characteristics are compared between the treatment-naïve and MAO-B inhibitor-treated PASADENA cohorts and between the PASADENA and PPMI populations.ResultsOf the 443 patients screened, 316 were enrolled into the PASADENA study between June 2017 and November 2018, with an average age of 59.9 years and 67.4% being male. The mean time from diagnosis at baseline was 10.11 months, with 75.3% in H&Y Stage II. Baseline motor and non-motor symptoms (assessed using Movement Disorder Society – Unified Parkinson’s Disease Rating Scale [MDS-UPDRS]) were similar in severity between the MAO-B inhibitor-treated and treatment-naïve PASADENA cohorts (MDS-UPDRS Total score [standard deviation (SD)]; 30.21 [11.96], 32.10 [13.20], respectively). The overall PASADENA population (63.6% treatment naïve and 36.4% on MAO-B inhibitor) also showed a similar severity in MDS-UPDRS scores (e.g. MDS-UPDRS Total score [SD]; 31.41 [12.78], 32.63 [13.04], respectively) to the PPMI cohort (all treatment naïve).ConclusionsThe PASADENA study population is suitable to investigate the potential of prasinezumab to slow disease progression in individuals with early PD.Trial RegistrationNCT03100149

The most common cause of familial frontotemporal lobar degeneration with TAR DNA-binding protein-43 pathology (FTLD-TDP) has been found to be an expansion of a hexanucleotide repeat (GGGGCC) in a noncoding region of the gene C9ORF72. Hippocampal sclerosis (HpScl) is a common finding in FTLD-TDP. Our objective was to screen for the presence of C9ORF72 hexanucleotide repeat expansions in a pathologically confirmed cohort of "pure" hippocampal sclerosis cases (n = 33), outside the setting of FTLD-TDP and Alzheimer's disease (AD). Using a recently described repeat-associated non-ATG (RAN) translation (C9RANT) antibody that was found to be highly specific for c9FTD/ALS, we identified a single "pure" HpScl autopsy case with a repeat expansion in C9ORF72 (c9HpScl). Mutation screening was also performed with repeat-primed polymerase chain reaction and further confirmed with Southern blotting. The c9HpScl patient had a 14-year history of a slowly progressive amnestic syndrome and a clinical diagnosis of probable AD. Neuropsychological testing revealed memory impairment, but no deficits in other cognitive domains. Autopsy showed hippocampal sclerosis with TDP-43 immunoreactive neuronal inclusions relatively limited to limbic lobe structures. Neuritic pathology immunoreactive for p62 was more frequent than TDP-43 in amygdala and hippocampus. Frequent p62-positive neuronal inclusions were present in cerebellar granule neurons as is typical of C9ORF72 mutation carriers. There was no significant FTLD or motor neuron disease. C9RANT was found to be sensitive and specific in this autopsy-confirmed series of HpScl cases. The findings in this patient suggest that the clinical and pathologic spectrum of C9ORF72 repeat expansion is wider than frontotemporal dementia and motor neuron disease, including cases of progressive amnestic dementia with restricted TDP-43 pathology associated with HpScl.

Objective To investigate the utility of a clinical laboratory ELISA format assay that measures neural thread protein (NTP) in urine in the assessment of patients presenting with cognitive symptoms. Design A prospective blinded multicentered study. Setting Eight US specialty clinics for the evaluation of cognitive or memory disorder or dementia, including memory disorder and dementia clinics, neurology clinics, and psychiatry clinics, in 8 states. Participants Prospectively enrolled consecutive patients who were newly referred to a specialty clinic for assessment of cognitive or memory disorder symptoms or dementia to rule out or rule in Alzheimer’s disease (AD). Measurements Participants provided a first morning urine sample for UNTP measurement for testing at a central core laboratory and subsequently went through specialized diagnostic evaluations in accordance with established clinical criteria. Urine NTP measurement was compared to the diagnostic categorization of the patients as probable or possible AD (according to National Institute of Neurological Communicative Disorders and Stroke and the Alzheimer Disease and Related Disorders Association [NINCDS-ADRDA] criteria), mild cognitive impairment (MCI) (according to Quality Standards Subcommittee of the American Academy of Neurology [AAN] criteria) or definite non-AD. Clinical diagnoses were made without reference to UNTP measurement; the testing laboratory was blinded to both patient identity and clinical diagnoses. Results A total of 168 enrolled and consented patients provided qualifying urine samples and completed specialized diagnostic workups. There were 91.4% of subjects with probable AD, 37.7% of subjects categorized as possible AD, and 48.6% of subjects with MCI who had an elevated NTP measurement (>22 μg/mL). There were 90.7% of subjects diagnosed as definite non-AD who had a normal NTP measurement (≤22 μg/mL). Conclusion Noninvasive UNTP test results are potentially helpful as part of the workup of dementia for the nonspecialist to help in the decision as to whether referral and/or more detailed investigation is advisable.