Plasma biomarkers of neurodegeneration in patients and high risk subjects with Lewy body disease.

Comorbid Alzheimer's disease (AD) neuropathology is common in Lewy body disease (LBD); however, AD comorbidity in the prodromal phase of LBD remains unclear. This study investigated AD comorbidity in the prodromal and symptomatic phases of LBD by analyzing plasma biomarkers in patients with Parkinson's disease (PD) and dementia with Lewy bodies (DLB) and individuals at risk of LBD (NaT-PROBE cohort). Patients with PD (PD group, n = 84) and DLB (DLB group, n = 16) and individuals with LBD with ≥ 2 (high-risk group, n = 82) and without (low-risk group, n = 37) prodromal symptoms were enrolled. Plasma amyloid-beta (Aß) composite was measured using immunoprecipitation-mass spectrometry assays. Plasma phosphorylated tau 181 (p-tau181), neurofilament light chain (NfL), and alpha-synuclein (aSyn) were measured using a single-molecule array. Plasma p-tau181 levels were higher in the PD and DLB groups than in the low-risk group. Aß composite level was higher in the DLB group than in the high-risk group. AD-related biomarker levels were not elevated in the high-risk group. NfL levels were higher in the high-risk, PD, and DLB groups than in the low-risk group. In the PD group, Aß composite was associated with cognitive function, p-tau181 with motor function and non-motor symptoms, and NfL with cognitive and motor functions and non-motor symptoms. In the high-risk group, NfL was associated with metaiodobenzylguanidine scintigraphy abnormalities. The PD and DLB groups exhibited comorbid AD neuropathology, though not in the prodromal phase. Elevated plasma NfL levels, even without elevated AD-related plasma biomarker levels, may indicate aSyn-induced neurodegeneration in the LBD prodromal phase.

Anodal Electrical Taste Stimulation to the Chin Enhances the Salt Taste Perception in Subarachnoid Hemorrhage Patients.

Aneurysmal subarachnoid hemorrhage (SAH) is a critical condition associated with high mortality rates. Hypertension is a significant risk factor for SAH development and recurrence following coil embolization for a ruptured aneurysm. While reduction of salt consumption is crucial for managing hypertension, it often compromises food taste. Anodal electrical taste stimulation (ETS) has been proposed to enhance taste perception without altering salt content. We present the case of a 69-year-old female SAH patient with a ruptured aneurysm at the anterior communicating artery who underwent coil embolization and in whom we tested ETS's efficacy in enhancing the salt taste perception on day 42 after the procedure. ETS effectively enhanced the salt taste perception threshold and perceived concentration; the threshold for salt taste without electrical stimulation was 0.8% of salt-impregnated filter paper, whereas that with electrical stimulation was 0.6%. The perception of salt taste was enhanced: 0.8% and 1.0% of filter papers were perceived as 0.6% and 0.8% without electrical stimulation and 1.0% and 1.2% with electrical stimulation, respectively. This is the first report describing the salt perception-enhancing effect of ETS in an actual patient. Further studies involving actual patients are required to determine how ETS affects habitual salt intake and blood pressure trends.