Halicka Monika, Cousins Olivia Rose, Ten Brink Antonia F, Vittersø Axel D, Proulx Michael J, Bultitude Janet H
Institute of Neuroscience, Universite catholique de Louvain, Brussels, Belgium.
Centre for Pain Research, University of Bath, Bath, UK.
J Pain Res. 2024 Apr 23;17:1519-1529. doi: 10.2147/JPR.S437366. eCollection 2024.
Alterations in spatial attention have been reported in people with chronic pain and may be relevant to understanding its cortical mechanisms and developing novel treatments. There is conflicting evidence as to whether people with Complex Regional Pain Syndrome (CRPS) have reduced visuospatial attention to their affected limb and/or its surrounding space, with some evidence that these deficits may be greater in personal (bodily) space. We aimed to test the competing hypotheses of whether the visuospatial attentional bias is specific to the personal space of the affected limb or generalizes to the personal space of other parts of the affected side of the body.
Using visual Temporal Order Judgement tasks, we measured spatial attention in the personal space of the hands and feet of patients with upper (n=14) or lower (n=14) limb CRPS and pain-free controls (n=17). Participants judged the order of two light flashes presented at different temporal offsets on each of their hands or feet. Slower processing of the flash on one side relative to the other reflects reduced attention to that side of space.
Controls prioritized stimuli on the non-dominant (left) relative to dominant side, consistent with the well-documented normal leftward bias of attention (ie "pseudoneglect"). Regardless of the location (upper or lower limb) of the pain or visual stimuli, people with CRPS showed no such asymmetry, representing reduced attention to the affected side (compared to the greater attention of controls to their non-dominant side). More severe CRPS symptoms were associated with a greater tendency to deprioritize stimuli on the affected side.
Our findings suggest that relative visuospatial bias in CRPS is generalized to the personal space of the affected side of the body, rather than being specific to the personal space of the CRPS-affected limb.
据报道，慢性疼痛患者存在空间注意力改变，这可能与理解其皮层机制及开发新治疗方法相关。关于复杂性区域疼痛综合征（CRPS）患者对其患侧肢体和/或其周围空间的视觉空间注意力是否降低，存在相互矛盾的证据，有证据表明这些缺陷在个人（身体）空间中可能更明显。我们旨在检验以下相互竞争的假设：视觉空间注意力偏差是特定于患侧肢体的个人空间，还是会扩展到身体患侧其他部位的个人空间。
使用视觉时间顺序判断任务，我们测量了上肢（n = 14）或下肢（n = 14）CRPS患者以及无痛对照组（n = 17）的手和脚的个人空间中的空间注意力。参与者判断在他们每只手或脚上以不同时间间隔呈现的两个闪光的顺序。一侧闪光的处理速度相对于另一侧较慢反映了对该侧空间的注意力降低。
对照组优先处理非优势（左侧）相对于优势侧的刺激，这与有充分记录的正常的向左注意力偏差（即“假性忽视”）一致。无论疼痛或视觉刺激位于上肢还是下肢，CRPS患者均未表现出这种不对称性，这表明他们对患侧的注意力降低（与对照组对非优势侧的更多注意力相比）。更严重的CRPS症状与将患侧刺激的优先级降低的更大倾向相关。
我们的研究结果表明，CRPS中的相对视觉空间偏差扩展到了身体患侧的个人空间，而不是特定于受CRPS影响的肢体的个人空间。
