Killgore William D S, Singh Prabhjyot, Kipman Maia, Pisner Derek, Fridman Andrew, Weber Mareen
Social, Cognitive and Affective Neuroscience Lab, University of Arizona College of Medicine, United States; McLean Hospital, Harvard Medical School, United States.
Social, Cognitive and Affective Neuroscience Lab, University of Arizona College of Medicine, United States.
Neurosci Lett. 2016 Jan 26;612:238-244. doi: 10.1016/j.neulet.2015.12.033. Epub 2015 Dec 19.
Most people who sustain a mild traumatic brain injury (mTBI) will recover to baseline functioning within a period of several days to weeks. A substantial minority of patients, however, will show persistent symptoms and mild cognitive complaints for much longer. To more clearly delineate how the duration of time since injury (TSI) is associated with neuroplastic cortical volume changes and cognitive recovery, we employed voxel-based morphometry (VBM) and select neuropsychological measures in a cross-sectional sample of 26 patients with mTBI assessed at either two-weeks, one-month, three-months, six-months, or one-year post injury, and a sample of 12 healthy controls. Longer duration of TSI was associated with larger gray matter volume (GMV) within the ventromedial prefrontal cortex (vmPFC) and right fusiform gyrus, and better neurocognitive performance on measures of visuospatial design fluency and emotional functioning. In particular, volume within the vmPFC was positively correlated with design fluency and negatively correlated with symptoms of anxiety, whereas GMV of the fusiform gyrus was associated with greater design fluency and sustained visual psychomotor vigilance performance. Moreover, the larger GMV seen among the more chronic individuals was significantly greater than healthy controls, suggesting possible enlargement of these regions with time since injury. These findings are interpreted in light of burgeoning evidence suggesting that cortical regions often exhibit structural changes following experience or practice, and suggest that with greater time since an mTBI, the brain displays compensatory remodeling of cortical regions involved in emotional regulation, which may reduce distractibility during attention demanding visuo-motor tasks.
大多数轻度创伤性脑损伤（mTBI）患者会在几天到几周内恢复到基线功能水平。然而，相当一部分患者会在更长时间内表现出持续症状和轻微的认知主诉。为了更清楚地描绘受伤时间（TSI）与神经可塑性皮质体积变化和认知恢复之间的关系，我们对26例mTBI患者进行了基于体素的形态学测量（VBM）并选择了神经心理学测量方法，这些患者在受伤后两周、一个月、三个月、六个月或一年接受评估，同时选取了12名健康对照者作为样本。TSI持续时间越长，与腹内侧前额叶皮质（vmPFC）和右侧梭状回内的灰质体积（GMV）越大以及视觉空间设计流畅性和情绪功能测量方面更好的神经认知表现相关。特别是，vmPFC内的体积与设计流畅性呈正相关，与焦虑症状呈负相关，而梭状回的GMV与更高的设计流畅性和持续的视觉心理运动警觉表现相关。此外，在病程较长的个体中观察到的较大GMV显著大于健康对照者，这表明自受伤以来这些区域可能随时间而扩大。这些发现是根据越来越多的证据来解释的，这些证据表明皮质区域在经历或练习后经常会出现结构变化，并表明mTBI后时间越长，大脑对参与情绪调节的皮质区域进行代偿性重塑，这可能会减少在需要注意力的视觉运动任务中的注意力分散。
