Application of the Japanese Verbal Learning Test to Patients With Alzheimer's Disease in the Early Stage.

INTRODUCTION: This study aimed to investigate the mechanism of memory function in the context of explicit memory in early-stage Alzheimer's disease (AD) using the short-form Japanese Verbal Learning Test (JVLT-9). METHODS: Participants were 20 patients with early-stage AD and a control group of 23 healthy older adults (normal controls: NC), each of whom was administered the JVLT-9, which is a verbal list learning task used to assess explicit memory comprehensively. Between-group differences for each score were investigated using the Mann-Whitney U test. A two-way analysis of variance (ANOVA) was performed for the number of correct recalls by group (AD/NC) × JVLT-9 task. In addition, the AD group was divided into a CDR 0.5 group and a CDR 1.0 group, and it was performed as a group (CDR 0.5/1.0) × JVLT-9 task two-way ANOVA. RESULTS: The results demonstrated that the AD group had lower immediate recall, learning rate, semantic clustering, and recognition discrimination and significantly higher intrusion errors compared to the NC group. Further, JVLT-9 recall and recognition rates were found to be lower with higher CDR (an index of dementia severity). CONCLUSION: These results are largely consistent with the features of explicit memory in AD reported in the English version, confirming the clinical utility of the JVLT-9 as a test of explicit memory function.

The relationship between script memory for everyday events and schizotypy: an investigation through a development of Japanese Situational Feature Recognition Test.

Background: Script memory is stored information about a sequential structure of an activity (e.g., going shopping), including what actors do, the purpose of the activity, and the likely consequences of the actor's actions. It has been reported that script memory is impaired among schizophrenia patients. The present research investigated the relationship between schizotypal personality tendencies (schizotypy) and script memory by testing Japanese individuals. Method: First, a new test to measure the intactness of the script memory was created by asking the public to report activities they often perform and what behaviors each activity contains. The test contains 15 everyday activities, each accompanied by 15 behavior choices, either strongly associated, completely unrelated, or weakly associated with the activity. Next, undergraduate participants were presented with the test and chose appropriate behaviors for each activity (Study 1 and 2). Their extent of schizotypy was measured using Schizotypal Personality Questionnaire Brief (SPQ-B). Study 3 targeted the public of various ages. In addition to Study 2 procedure, participants reported the extent of psychological burden for performing each activity, their life satisfaction, and subjective evaluation of their memory ability. Results: All studies consistently found that the script memory performance was worse for individuals with higher schizotypy. Signal detection indices for accurate discrimination between correct and incorrect choices, which were A' in Study 1 and C in Study 2 and 3, negatively correlated with the SPQ-B scores (r = -0.16, -0.11, -0.17, respectively). Study 3 found that the relationship between schizotypy and memory task performance was mediated by the extent of psychological burden. When a signal detection index (d') for the memory task was regressed on the SPQ-B, while the psychological burden scores being a mediator, the mediation effect was significant (B = 0.003, SE = 0.001, 95% CI [0.001, 0.005]). Conclusion: Individuals with higher schizotypy seem to associate unrelated behaviors to an event, forming script memory with irrelevant information, maybe due to the schizotypy symptom of having peculiar thoughts. The newly created test must be validated using a clinical population to expand its potential to be used in clinical research.

Is there a spinal tap responder in progressive supranuclear palsy? The first prospective study.

OBJECTIVE: Progressive supranuclear palsy (PSP) is a progressive neurodegenerative disease, and sometimes shows idiopathic normal pressure hydrocephalus (iNPH)-like presentations. We aimed to evaluate spinal tap responsiveness in patients with PSP, including the effect of sham spinal tap. METHODS: Eleven patients with PSP, ten with probable/definite iNPH, and eight control patients were prospectively enrolled. All participants underwent sham spinal tap and spinal tap procedures. Gait was evaluated using wearable inertial sensors. We defined "tap responders" as individuals with a 10% or more improvement from baseline in any of the gait parameters (timed up-and-go test total time, stride length, and velocity during straight walking under single-task and cognitive dual-task conditions). We compared the ratio of responders in patients with PSP to patients with iNPH and controls. RESULTS: The ratio of tap responders and the ratio of sham tap responders in patients with PSP were significantly higher than those in control patients, and not different from those in patients with iNPH. PSP patients with iNPH-like MRI features tended to respond to the spinal tap compared to those without such imaging features. Notably, one patient with PSP, who responded to the spinal tap beyond the effect of sham spinal tap, was treated by the shunt operation. CONCLUSION: This is the first prospective study to demonstrate tap and shunt responsiveness in patients with PSP while highlighting the placebo effects of the spinal tap in patients with PSP or iNPH. Our findings suggest that some PSP patients have impaired cerebrospinal fluid circulation, contributing to a distinct component of the clinical spectrum.

Decreased short-latency afferent inhibition in individuals with mild cognitive impairment: A TMS-EEG study.

TMS combined with EEG (TMS-EEG) is a tool to characterize the neurophysiological dynamics of the cortex. Among the TMS paradigms, short-latency afferent inhibition (SAI) allows the investigation of inhibitory effects mediated by the cholinergic system. The aim of this study was to compare cholinergic function in the DLPFC between individuals with mild cognitive impairment (MCI) and healthy controls (HC) using TMS-EEG with the SAI paradigm. In this study, 30 MCI and 30 HC subjects were included. The SAI paradigm consisted of 80 single pulse TMS and 80 SAI stimulations applied to the left DLPFC. N100 components, global mean field power (GMFP) and total power were calculated. As a result, individuals with MCI showed reduced inhibitory effects on N100 components and GMFP at approximately 100 ms post-stimulation and on ß-band activity at 200 ms post-stimulation compared to HC. Individuals with MCI showed reduced SAI, suggesting impaired cholinergic function in the DLPFC compared to the HC group. We conclude that these findings underscore the clinical applicability of the TMS-EEG method as a powerful tool for assessing cholinergic function in individuals with MCI.