From the Department of Radiology and Imaging Sciences (J.W.A., A.T., J.L.S.), Emory University, Atlanta, Georgia
Department of Neurology (J.W.A.), Emory University, Atlanta, Georgia.
AJNR Am J Neuroradiol. 2021 May;42(5):930-937. doi: 10.3174/ajnr.A7007. Epub 2021 Feb 11.
Vestibular symptoms are common after concussion. Vestibular Ocular Motor Screening identifies vestibular impairment, including postconcussive visual motion sensitivity, though the underlying functional brain alterations are not defined. We hypothesized that alterations in multisensory processing are responsible for postconcussive visual motion sensitivity, are detectable on fMRI, and correlate with symptom severity.
Twelve patients with subacute postconcussive visual motion sensitivity and 10 healthy control subjects underwent vestibular testing and a novel fMRI visual-vestibular paradigm including 30-second "neutral" or "provocative" videos. The presence of symptoms/intensity was rated immediately after each video. fMRI group-level analysis was performed for a "provocative-neutral" condition. -statistic images were nonparametrically thresholded using clusters determined by > 2.3 and a corrected cluster significance threshold of = .05. Symptoms assessed on Vestibular Ocular Motor Screening were correlated with fMRI mean parameter estimates using Pearson correlation coefficients.
Subjects with postconcussive visual motion sensitivity had significantly more Vestibular Ocular Motor Screening abnormalities and increased symptoms while viewing provocative videos. While robust mean activation in the primary and secondary visual areas, the parietal lobe, parietoinsular vestibular cortex, and cingulate gyrus was seen in both groups, selective increased activation was seen in subjects with postconcussive visual motion sensitivity in the primary vestibular/adjacent cortex and inferior frontal gyrus, which are putative multisensory visual-vestibular processing centers. Moderate-to-strong correlations were found between Vestibular Ocular Motor Screening scores and fMRI activation in the left frontal eye field, left middle temporal visual area, and right posterior hippocampus.
Increased fMRI brain activation in visual-vestibular multisensory processing regions is selectively seen in patients with postconcussive visual motion sensitivity and is correlated with Vestibular Ocular Motor Screening symptom severity, suggesting that increased visual input weighting into the vestibular network may underlie postconcussive visual motion sensitivity.
眩晕症状在脑震荡后很常见。前庭眼动筛查可识别前庭功能障碍，包括脑震荡后视觉运动敏感，但尚未明确其潜在的功能性大脑改变。我们假设，多感觉处理的改变是导致脑震荡后视觉运动敏感的原因，可通过 fMRI 检测到，并与症状严重程度相关。
12 例亚急性脑震荡后视觉运动敏感患者和 10 例健康对照者接受了前庭测试和一种新的 fMRI 视觉-前庭范式，包括 30 秒的“中性”或“刺激性”视频。视频结束后立即对症状/强度进行评分。对“刺激性-中性”条件进行 fMRI 组水平分析。采用＞2.3 的簇和校正的簇显著水平阈值（ =.05）进行非参数阈值处理。使用 Pearson 相关系数将 Vestibular Ocular Motor Screening 评估的症状与 fMRI 平均参数估计值相关联。
脑震荡后视觉运动敏感患者的 Vestibular Ocular Motor Screening 异常和刺激性视频观看时症状增加更为明显。两组均可见初级和次级视觉区、顶叶、顶颞叶前庭皮质和扣带回的强烈平均激活，但在脑震荡后视觉运动敏感患者中，初级前庭/相邻皮质和下额回可见选择性增强激活，这些区域是多感觉视觉-前庭处理中心。Vestibular Ocular Motor Screening 评分与 fMRI 左额眼区、左中颞视觉区和右后海马区的激活之间存在中度至强相关性。
脑震荡后视觉运动敏感患者的视觉-前庭多感觉处理区域的 fMRI 脑激活增加，与 Vestibular Ocular Motor Screening 症状严重程度相关，提示视觉输入对前庭网络的权重增加可能是脑震荡后视觉运动敏感的原因。
