Journal of Alzheimer's disease : JAD
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The aim was to evaluate brain amyloid-β (Aβ) deposition in patients with mild cognitive impairment (MCI) due to Alzheimer's disease (AD) using amyloid PET imaging and clarify the relationship between the annual change in Aβ deposition and disease progression. Forty-eight MCI patients underwent neuropsychological assessment and amyloid PET imaging using [11C]-PIB over a follow-up of 5.7±1.5 years. Thirty-nine MCI patients who had an amyloid-positive scan were defined as MCI due to AD, and 9 MCI patients who had an amyloid-negative scan were included. ⋯ In patients who progressed during a short duration of 1.7±0.8 years, the annual rate of increase in PIB SUVR was 0.101±0.094 (n = 16, p < 0.05), which was greater compared to patients with long conversion or stable patients. There was a negative correlation between the annual rate of increase in PIB SUVR and duration of progression to AD among individual MCI converters (r = -0.47, n = 28, p < 0.05). The patients defined as MCI due to AD could progress to AD with a shorter period if they have a greater increased annual rate in brain Aβ deposition.
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The Montreal Cognitive Assessment (MoCA) has a high sensitivity for detecting cognitive dysfunction. Swedish normative data does not exist and international norms are often derived from populations where cognitive impairment has not been screened for and not been thoroughly assessed to exclude subjects with dementia or mild cognitive impairment. ⋯ We present detailed normative MoCA data and cut-offs according to the DSM-5 criteria for cognitive impairment based on a large population-based cohort of elderly individuals, screened and thoroughly investigated to rule out cognitive impairment. Level of education, sex, and age should be taken in account when evaluating MoCA score, which is facilitated by our online regression-based calculator that provide percentile and z-score for a subject's MoCA score.
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Verubecestat is a potent BACE1 enzyme inhibitor currently being investigated in Phase III trials for the treatment of mild-to-moderate and prodromal Alzheimer's disease. Multiple anti-amyloid immunotherapies have been dose-limited by adverse amyloid related imaging abnormalities such as vasogenic edema (ARIA-E) and microhemorrhage (ARIA-H) observed in human trials and mice. Verubecestat was tested in a 12-week nonclinical study for the potential to exacerbate microhemorrhage (ARIA-H) profiles in 18-22-month-old post-plaque Tg2576-AβPPswe mice. ⋯ Stereological analysis of cortex and hippocampus plaque load similarly revealed significantly reduced area of Aβ immunoreactivity and reduced plaque number in verubecestat-treated animals compared to controls. The absence of elevated ARIA events in verubecestat-treated mice was associated with a significant reduction in the level of accumulated CNS amyloid pathology and brain Aβ peptides; effects consistent with the desired therapeutic mechanism of verubecestat in AD patients. These data will be compared with longitudinal MRI profiles from ongoing clinical trials.
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Randomized Controlled Trial
Effects of DHA Supplementation on Hippocampal Volume and Cognitive Function in Older Adults with Mild Cognitive Impairment: A 12-Month Randomized, Double-Blind, Placebo-Controlled Trial.
Docosahexaenoic acid (DHA) is important for brain function, and higher DHA intake is inversely correlated with relative risk of Alzheimer's disease. The potential benefits of DHA supplementation in people with mild cognitive impairment (MCI) have not been fully examined. Our study aimed to determine the effect of DHA supplementation on cognitive function and hippocampal atrophy in elderly subjects with MCI. ⋯ In addition, there were significant differences in volumes of left hippocampus (ηp2 = 0.121, p = 0.016), right hippocampus (ηp2 = 0.757, p = 0.008), total hippocampus (ηp2 = 0.124, p = 0.023), and global cerebrum (ηp2 = 0.145, p = 0.032) between the two groups. These findings suggest that DHA supplementation (2 g/day) for 12 months in MCI subjects can significantly improve cognitive function and slow the progression of hippocampal atrophy. Larger, longer-term confirmatory studies are warranted.
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Patients with pathogenic truncating mutations in the prion gene (PRNP) usually present with prolonged disease courses with severe neurofibrillary tangle and cerebral amyloidosis pathology, but more atypical phenotypes also occur, including those with dysautonomia and peripheral neuropathy. We describe the neurological, cognitive, neuroimaging, and electrophysiological features of a 31-year-old man presenting with an orbitofrontal syndrome, gastrointestinal symptoms, and peripheral neuropathy associated with PRNP Q160X nonsense mutation, with symptom onset at age 27. ⋯ This case strengthens the evidence suggesting an association between PRNP truncating mutations and prion systemic amyloidosis. PRNP gene testing should be considered in any patient with atypical dementia, especially with early onset and neuropathy, even in the absence of a family history.