Boys Town National Research Hospital, Institute for Human Neuroscience, Boys Town, Nebraska, USA.
College of Medicine, University of Nebraska Medical Center (UNMC), Omaha, Nebraska, USA.
Hum Brain Mapp. 2021 Jun 15;42(9):2851-2861. doi: 10.1002/hbm.25408. Epub 2021 Mar 18.
HIV-infection has been associated with widespread alterations in brain structure and function, although few studies have examined whether such aberrations are co-localized and the degree to which clinical and cognitive metrics are related. We examine this question in the somatosensory system using high-resolution structural MRI (sMRI) and magnetoencephalographic (MEG) imaging of neural oscillatory activity. Forty-four participants with HIV (PWH) and 55 demographically-matched uninfected controls completed a paired-pulse somatosensory stimulation paradigm during MEG and underwent 3T sMRI. MEG data were transformed into the time-frequency domain; significant sensor level responses were imaged using a beamformer. Virtual sensor time series were derived from the peak responses. These data were used to compute response amplitude, sensory gating metrics, and spontaneous cortical activity power. The T1-weighted sMRI data were processed using morphological methods to derive cortical thickness values across the brain. From these, the cortical thickness of the tissue coinciding with the peak response was estimated. Our findings indicated both PWH and control exhibit somatosensory gating, and that spontaneous cortical activity was significantly stronger in PWH within the left postcentral gyrus. Interestingly, within the same tissue, PWH also had significantly reduced cortical thickness relative to controls. Follow-up analyses indicated that the reduction in cortical thickness was significantly correlated with CD4 nadir and mediated the relationship between HIV and spontaneous cortical activity within the left postcentral gyrus. These data indicate that PWH have abnormally strong spontaneous cortical activity in the left postcentral gyrus and such elevated activity is driven by locally reduced cortical gray matter thickness.
HIV 感染与大脑结构和功能的广泛改变有关，尽管很少有研究检查这些异常是否共存，以及临床和认知指标与这些异常的关联程度。我们使用高分辨率结构磁共振成像（sMRI）和神经振荡活动的脑磁图（MEG）成像来检查感觉系统中的这个问题。44 名 HIV 感染者（PWH）和 55 名年龄匹配的未感染者完成了 MEG 中的感觉刺激对脉冲刺激范式，并进行了 3T sMRI 检查。MEG 数据转换为时频域；使用波束形成器对有意义的传感器水平响应进行成像。从峰值响应中得出虚拟传感器时间序列。这些数据用于计算响应幅度、感觉门控指标和自发皮质活动功率。使用形态学方法处理 T1 加权 sMRI 数据，以得出整个大脑的皮质厚度值。从中，估计与峰值响应对应的组织的皮质厚度。我们的研究结果表明，PWH 和对照组都表现出感觉门控，并且 PWH 在左侧中央后回的自发皮质活动明显更强。有趣的是，在相同的组织中，PWH 的皮质厚度也明显低于对照组。后续分析表明，皮质厚度的减少与 CD4 最低点显著相关，并介导了 HIV 与左侧中央后回自发皮质活动之间的关系。这些数据表明，PWH 在左侧中央后回有异常强烈的自发皮质活动，这种活动是由局部皮质灰质厚度减少驱动的。
