The influence of spatial selective attention on the development of secondary hyperalgesia - A replication study

Central sensitization provokes hypersensitivity/hyperalgesia and plays a key role in the development and maintenance of chronic pain. For several years, scientists have been exploring the cognitive function of attention, related top-down pathways and their relation to pain. Attention seems to be a factor that could potentially improve the development of new approaches regarding prevention and treatment of chronic pain. Recently, the first studies concerning the modulation of secondary hyperalge-sia/hypersensitivity by spatial selective attention have been carried out. This thesis consists of two parts: first, a literature review of pain and its modulation is provided, focussing on attentional processes. The second part consist of a replication study and builds the core part of this work. Three hypotheses have been investigated: (1) high-frequency stimulation (HFS) is a valid method to induce secondary hyperalge-sia/hypersensitivity (2) the amount and (3) the extension of hyperalge-sia/hypersensitivity can be modulated by manipulating one’s attention. Seventy-two healthy participants took part in the study aimed to explore atten-tional manipulation and its influence on the development of hyperalge-sia/hypersensitivity. While performing a somatosensory task that required focus on only one arm, high-frequency stimulation was applied on both of their forearms. Sen-sitivity to pinprick stimulation was measured before (T0), immediately after (T1) and 20 minutes after (T2) the application of high-frequency stimulation with the soma-tosensory task. The amount and extension of hyperalgesia/hypersensitivity were compared between both arms. The first hypothesis has been confirmed whereas no significant results have been found to confirm the second and third hypothesis. Potential factors influencing the results are discussed and possible limitations are defined. Future studies are needed to explore the relation between spatial selective at-tention and central sensitization, and to provide new approaches for effective inter-ventions in chronic pain treatment.