1National Military Audiology and Speech Center, Walter Reed National Military Medical Center, Bethesda, Maryland.
2National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, Maryland.
J Neurotrauma. 2019 Aug 15;36(16):2443-2453. doi: 10.1089/neu.2018.5630. Epub 2019 May 3.
Service members (SMs) who have suffered mild traumatic brain injury due to blast exposure (b/TBI) often report post-concussive symptoms consistent with auditory, visual, or vestibular impairments even when they score within the normal range on traditional clinical tests of sensory function. One possible explanation for this discrepancy is that patients who score in the low normal range in more than one sensory modality may be severely impaired in tasks that require multisensory integration. This study evaluated unimodal and multimodal sensory performance in SMs with b/TBI and healthy controls by having them conduct four tasks while walking or standing in an immersive virtual environment: an Auditory Localization task (AL) where they moved a cursor to the perceived location of a sound; a Visual Discrimination task (VD) where they distinguished between two visual targets; an Aurally-Aided Visual Search Task (AAVS) where they used an auditory cue to locate and identify a visual target hidden in a field of visual distractors; and a Visual-Only Visual Search task (VOVS) where they located and identified a visual target in a field of distractors with no auditory cue. The results show the b/TBI and healthy control groups performed equivalently in the AL and VD tasks, but that the b/TBI group responded roughly 15% slower in the AAVS task and 50% slower in the VOVS task. Walking had no effect on performance in the visual-only tasks, but both groups responded faster while walking in the AL and AAVS tasks without any reduction in accuracy.
经历爆炸导致的轻度创伤性脑损伤（b/TBI）的军人经常报告与听觉、视觉或前庭功能障碍一致的脑震荡后症状，即使他们在传统的感觉功能临床测试中得分正常。造成这种差异的一个可能原因是，在多种感觉模式中得分低于正常范围的患者，在需要多感觉整合的任务中可能会严重受损。本研究通过让经历爆炸导致的轻度创伤性脑损伤的军人和健康对照者在沉浸式虚拟环境中行走或站立时执行四项任务，评估他们的单模态和多模态感觉性能：听觉定位任务（AL），他们在该任务中移动光标到感知到的声音位置；视觉辨别任务（VD），他们在该任务中区分两个视觉目标；听觉辅助视觉搜索任务（AAVS），他们使用听觉提示定位和识别隐藏在视觉干扰器场中的视觉目标；以及仅视觉视觉搜索任务（VOVS），他们在没有听觉提示的情况下在视觉干扰器场中定位和识别视觉目标。结果表明，b/TBI 组和健康对照组在 AL 和 VD 任务中的表现相当，但 b/TBI 组在 AAVS 任务中的反应速度慢了约 15%，在 VOVS 任务中的反应速度慢了 50%。视觉仅任务不受行走的影响，但两组在无视觉提示的 AL 和 AAVS 任务中行走时反应速度都更快，准确性没有降低。
