Pain Thresholds as a Putative Functional Test for Cerebral Laterality in Major Depressive Disorder and Panic Disorder¹

Abstract

Objective: Both major depressive disorder (MDD) and panic disorder (PD) exhibit an illness-related functional cerebral laterality with a frontal right/left asymmetry. Using experimental pain lateralization as a putative indicator of functional cerebral laterality, we assessed body side differences in pressure, cold and heat pain thresholds in patients with MDD and PD as well as in healthy control subjects (HC). To control for an attentional bias in perception, reaction times for selective attention were also measured for both visual fields. Method: 21 inpatients with MDD, 21 inpatients with PD (DSM-IV diagnosis) and 20 HC subjects, all right-handed, were investigated drug free. Pain thresholds for pressure, cold and heat were assessed at the right and left forearm or hand. A neuropsychological standard test was used to measure selective attention (signal detection, Wiener Testsystem), which allows for the discrimination between left and right visual field stimulus processing. Results: In all participants, a left-sided increased pain sensitivity could be verified by using pressure pain, but not by thermal pain (cold, heat). The diagnosis of MDD or PD had no influence on pain threshold lateralization. There were no differences in reaction times of selective attention between the groups of patients and the HC. Neither did stimulus presentation in the left or right visual field affect reaction time differently. Conclusion: Body side asymmetry of pain perception was only found for pressure pain targeting mainly deep tissue (muscle) nociception. This asymmetry, however, cannot be regarded as an indicator of a pathological functional cerebral laterality in MDD and PD.

Three-dimensional scapulothoracic motion following treatment for breast cancer

“…Additionally, physical changes in muscle and joint movement have been shown in our studies [20]. Since decreased pain threshold on the left has consistently been shown to apply to deep pressure stimuli such as that transmitted by muscle nociceptors [29,41], it is possible that high levels of pain in left side affected patients is due to muscle nociceptor stimulation. Right side affected patients may overcome some pain and dysfunction due to the need to use the dominant arm.…”

L’évaluation expérimentale de la douleur dans la dépression majeure

“…Indépendamment de la modalité de stimulation, neuf études ont trouvé que les seuils de douleur étaient élevés dans la DM, relativement aux sujets sains [1,[3][4][5]26,27,32,42,43]. Ces seuils étaient diminués dans trois études [4,36,45] et quatre études ont échoué à trouver des différences entre les groupes [19,26,43,47].…”

“…Ces seuils étaient diminués dans trois études [4,36,45] et quatre études ont échoué à trouver des différences entre les groupes [19,26,43,47].…”

“…Indépendamment de la mesure de la douleur (seuil de douleur, tolérance à la douleur, douleur subjective, mais pas les seuils de sensation), des signes d'hypoalgésie dans la DM, par rapport aux sujets sains, ont été décrits dans sept études utilisant des stimuli thermiques [3][4][5]13,27,31,42], trois études ont rapporté des signes d'hyperalgésie [19,36,45], alors que cinq études ont échoué à démontrer des différences intergroupes sur certaines réponses [17,26,36,43,47].…”

“…Deux études utilisant des stimuli mécaniques ont montré des réponses diminuées à la douleur dans la DM par rapport aux sujets sains [26,43], alors qu'une autre étude a noté une absence de différences entre les patient(e)s avec la DM et les sujets sains [19] (indépendamment de la mesure de la douleur).…”