Spagnolo Primavera A, Parker Jacob A, Hallett Mark, Horovitz Silvina
Mary Horrigan Connors Center for Women's Health and Gender Biology, Brigham and Women's Hospital, Boston, MA, USA.
Department of Psychiatry, Brigham and Women's Hospital, Boston, MA, USA.
medRxiv. 2024 Jul 24:2024.07.23.24310881. doi: 10.1101/2024.07.23.24310881.
Aberrant interoceptive processing has been hypothesized to contribute to the pathophysiology of functional neurological disorder, although findings have been inconsistent. Here, we utilized functional magnetic resonance imaging (fMRI) to examine neural correlates of interoceptive attention - the conscious focus and awareness of bodily sensations - in functional movement disorder (FMD).
We used voxelwise analyses to compare blood oxygenation level-dependent responses between 13 adults with hyperkinetic FMD and 13 healthy controls (HCs) during a task requiring attention to different bodily sensations and to an exteroceptive stimulus. Additionally, we examined between-group differences in self-reported measures of interoception and evaluated their relationship with neural activity.
Interoceptive conditions (heartbeat, stomach and 'body', indicating sensations from the body part or limb affected in FMD participants) activated a network involving the precuneus, the posterior cingulate cortex (PCC) and caudate nucleus (CN) bilaterally, and the right anterior insula (aINS) ( <0.05, corrected). Group differences in brain activity were mainly driven by processing of disease-related interoceptive signals, which in the FMD group was associated with a broader neural activation than monitoring gastric interoception, while no group differences were detected during cardiac interoception. Differences based on interoceptive focus ( heartbeat and stomach) between FMD subjects and HCs were found in PCC, CN, angular gyrus, thalamus, and in the mid-insula ( <0.05, corrected).
This is, to our knowledge, the first study showing that FMD is associated with abnormal interoceptive processing in regions involved in monitoring body state, attentional focus, and homeostatic inference.
尽管研究结果并不一致，但有假说认为异常的内感受处理可能导致功能性神经障碍的病理生理过程。在此，我们利用功能磁共振成像（fMRI）来研究功能性运动障碍（FMD）中内感受性注意力（对身体感觉的有意识关注和觉察）的神经关联。
我们采用体素分析，比较了13名患有运动过多型FMD的成年人与13名健康对照者（HCs）在一项需要关注不同身体感觉和一个外感受性刺激的任务期间，基于血氧水平依赖的反应。此外，我们检查了内感受自我报告测量中的组间差异，并评估了它们与神经活动的关系。
内感受条件（心跳、胃部和“身体”，后者表示FMD参与者受影响身体部位或肢体的感觉）激活了一个双侧涉及楔前叶、后扣带回皮质（PCC）和尾状核（CN）以及右侧前脑岛（aINS）的网络（<0.05，校正后）。大脑活动的组间差异主要由与疾病相关的内感受信号处理驱动，在FMD组中，这与比监测胃部内感受更广泛的神经激活相关，而在心脏内感受期间未检测到组间差异。在PCC、CN、角回、丘脑和脑岛中部发现了FMD受试者与HCs之间基于内感受焦点（心跳和胃部）的差异（<0.05，校正后）。
据我们所知，这是第一项表明FMD与参与监测身体状态、注意力焦点和内稳态推理的区域中异常的内感受处理相关的研究。
