6th Edition of Neurology World Conference 2026

Abstract

Alzheimer’s disease (AD) is a neurodegenerative disease affecting 50 million people worldwide, characterized by brain atrophy, memory loss, and cognitive decline. While much has been researched about the neuropathology and cognitive decline of AD, the motor symptoms received less attention. Previous studies that have conducted the Line Bisection Test (LBT) on AD patients failed to identify abnormal results. However, some studies have added measures to induce an attentional bias in the participant, such as the character line bisection task and optokinetic stimulation. So, in this study, I aimed to determine if AD patients’ bilateral temporoparietal damage can be detected through the Line Quadrisection Test (LQT), a novel test modified from the Line Bisection Test (LBT). In the LQT, participants must mark a vertical line's ¼, ½, and ¾ positions. I conducted the LQT on 50 Alzheimer’s disease dementia (ADD) patients and 50 normal controls (NC). When marking the ¼ and ¾ points, ADD patients deviated more laterally than normal people but showed normal results on the bisection task (1/2 point). When quadrisecting the lines, the participants’ attentional focus shifts toward each end, and the reduced spatial awareness of ADD patients causes a more drastic deviation. Thus, this study reveals that LQT detects the spatial abnormalities of ADD patients that weren’t noticed in the LBT and can be used as a simple but effective tool to diagnose AD in advance. While current diagnostic measures like MRI and PET are too costly and cognitive tests are lengthy and burdensome, the LQT can indicate the possibility of AD in a faster and more affordable way. Furthermore, the LQT can be made in a digital app format, enabling people to conduct the test independently regardless of time and place, contributing to wider access to pre-diagnostic measures for AD. Thus, this study not only illuminates a novel aspect of an abnormal motor symptom of AD but also has valuable implications for wider access in pre-diagnosing AD.