Publications by authors named "Ryosuke Shimasaki"
Diagnostic Challenge in Frontal Variant Alzheimer's Disease With Low Amyloid-β PET Retention.
Ann Clin Transl Neurol
July 2025
Diagnosing frontal variant Alzheimer's disease (fvAD) is difficult and could be even more difficult when amyloid-beta (Aβ) PET retention is low. A 63-year-old woman presenting with a 3-year history of apathy and memory impairment showed executive dysfunction, memory impairment, and severe bilateral frontotemporal atrophy on MRI. Aβ PET showed only equivocal findings in the right frontal lobe and was negative.
View Article and Find Full Text PDFAs society ages, the number of people with dementia increases worldwide, and the prevention of dementia has become increasingly important. Lifestyle diseases are associated with the development of dementia, and preventing or controlling lifestyle diseases in middle-aged individuals is particularly important. Hypertension, diabetes, and dyslipidemia are associated with dementia.
View Article and Find Full Text PDFArticle Synopsis
- α-synuclein seed amplification assays (α-syn SAA) show promise but may have reduced sensitivity due to variations among patients with Lewy body disease (LBD).
- In a study of 34 Parkinson's disease (PD) patients and 7 with dementia with Lewy bodies (DLB), 85.2% of those with abnormal cardiac MIBG scans tested positive for α-syn SAA, while only 14.3% of those with normal scans did.
- MIBG cardiac scintigraphy was identified as a significant factor influencing α-syn SAA positivity, indicating that while α-syn SAA can be sensitive for LBD in specific cases, its effectiveness may be diminished in patients with normal M
Article Synopsis
- In Parkinson's disease patients, levels of cerebrospinal fluid metabolites homovanillic acid (HVA) and 5-hydroxyindole acetic acid (5-HIAA), which are linked to dopamine and serotonin, are found to be decreased.
- A study involving 57 drug-naïve PD patients indicated significant differences in 5-HIAA levels between those with positive vs negative cardiac MIBG imaging, suggesting a direct association.
- Additionally, a correlation was found between HVA levels and striatal dopamine transporter binding, confirming that both HVA and 5-HIAA have important roles in PD pathology and imaging outcomes.