Francis Houde1, Marylie Martel2, Alexia Coulombe-Lévêque3, Marie-Philippe Harvey4, Vincent Auclair5, David Mathieu6, Kevin Whittingstall7, Philippe Goffaux8, Guillaume Léonard9. 1. Centre de recherche sur le vieillissement, CIUSSS de l'Estrie - CHUS, 1036, rue Belvédère Sud, Sherbrooke, Qc J1H 4C4, Canada; Centre de recherche du CHUS, CIUSSS de l'Estrie - CHUS, 3001, 12e Avenue Nord, Sherbrooke, Qc J1H 5N4, Canada; Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12e avenue Nord, Qc J1H 5N4, Canada. Electronic address: francis.houde@usherbrooke.ca. 2. Centre de recherche sur le vieillissement, CIUSSS de l'Estrie - CHUS, 1036, rue Belvédère Sud, Sherbrooke, Qc J1H 4C4, Canada; Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12e avenue Nord, Qc J1H 5N4, Canada. Electronic address: marylie.martel@usherbrooke.ca. 3. Centre de recherche sur le vieillissement, CIUSSS de l'Estrie - CHUS, 1036, rue Belvédère Sud, Sherbrooke, Qc J1H 4C4, Canada; Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12e avenue Nord, Qc J1H 5N4, Canada. Electronic address: alexia.coulombe-leveque@usherbrooke.ca. 4. Centre de recherche sur le vieillissement, CIUSSS de l'Estrie - CHUS, 1036, rue Belvédère Sud, Sherbrooke, Qc J1H 4C4, Canada; Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12e avenue Nord, Qc J1H 5N4, Canada. Electronic address: marie.philippe.harvey@usherbrooke.ca. 5. Centre de recherche du CHUS, CIUSSS de l'Estrie - CHUS, 3001, 12e Avenue Nord, Sherbrooke, Qc J1H 5N4, Canada; Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12e avenue Nord, Qc J1H 5N4, Canada. Electronic address: vincent.auclair@usherbrooke.ca. 6. Neurosurgery, Neuro-oncology and Radiobiology departments, Université de Sherbrooke, 3001, 12e Avenue Nord, Qc J1H 5N4, Canada; Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12e avenue Nord, Qc J1H 5N4, Canada. Electronic address: david.mathieu@usherbrooke.ca. 7. Centre de recherche du CHUS, CIUSSS de l'Estrie - CHUS, 3001, 12e Avenue Nord, Sherbrooke, Qc J1H 5N4, Canada; Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12e avenue Nord, Qc J1H 5N4, Canada. Electronic address: kevin.whittingstall@usherbrooke.ca. 8. Centre de recherche du CHUS, CIUSSS de l'Estrie - CHUS, 3001, 12e Avenue Nord, Sherbrooke, Qc J1H 5N4, Canada; Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12e avenue Nord, Qc J1H 5N4, Canada. Electronic address: philippe.goffaux@usherbrooke.ca. 9. Centre de recherche sur le vieillissement, CIUSSS de l'Estrie - CHUS, 1036, rue Belvédère Sud, Sherbrooke, Qc J1H 4C4, Canada; Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12e avenue Nord, Qc J1H 5N4, Canada. Electronic address: guillaume.leonard2@usherbrooke.ca.
Abstract
BACKGROUND: Past studies have shown that pain memories are often inaccurate, a phenomenon known as mnemonic pain bias. Pain memories are thought to play an important role on how future pain is felt. Recent evidence from our laboratory suggests that individuals who exaggerate past pain display increased superior temporal gyrus (STG) activity during the encoding of experimental painful stimulations, suggesting that this brain structure plays an important role in pain memories. OBJECTIVE: /hypothesis. To determine whether a virtual lesion paradigm, targeting the STG during pain encoding, can affect long-lasting pain memories. We hypothesized that interfering with the activity of the STG would attenuate mnemonic bias. METHODS: Randomized double-blind study with two parallel groups. Participants received either sham (n = 21) or real (n = 21) transcranial magnetic stimulation (TMS - virtual lesion paradigm) over the STG during pain encoding (milliseconds after the administration of a painful stimuli). Pain intensity and unpleasantness were evaluated using a visual analog scale (VAS; 0 to 10) immediately after the painful event, and at recall, 2 months later. The mnemonic pain bias (calculated by subtracting the pain scores obtained at recall from the pain score obtained during encoding) was compared between the two groups for both pain intensity and unpleasantness. RESULTS: Participants in both groups did not differ in terms of age and gender (real TMS = 27 years ± 9, 43% female; sham TMS = 25 years ± 4, 49% female; p > 0.64). The mnemonic bias related to pain intensity was similar in both groups (p = 0.83). However, the mnemonic bias related to pain unpleasantness was lower in the real TMS group (p = 0.04). CONCLUSIONS: Our results provide the first evidence that the STG, is causally involved in the formation of biased memories of pain unpleasantness.
RCT Entities:
BACKGROUND: Past studies have shown that pain memories are often inaccurate, a phenomenon known as mnemonic pain bias. Pain memories are thought to play an important role on how future pain is felt. Recent evidence from our laboratory suggests that individuals who exaggerate past pain display increased superior temporal gyrus (STG) activity during the encoding of experimental painful stimulations, suggesting that this brain structure plays an important role in pain memories. OBJECTIVE: /hypothesis. To determine whether a virtual lesion paradigm, targeting the STG during pain encoding, can affect long-lasting pain memories. We hypothesized that interfering with the activity of the STG would attenuate mnemonic bias. METHODS: Randomized double-blind study with two parallel groups. Participants received either sham (n = 21) or real (n = 21) transcranial magnetic stimulation (TMS - virtual lesion paradigm) over the STG during pain encoding (milliseconds after the administration of a painful stimuli). Pain intensity and unpleasantness were evaluated using a visual analog scale (VAS; 0 to 10) immediately after the painful event, and at recall, 2 months later. The mnemonic pain bias (calculated by subtracting the pain scores obtained at recall from the pain score obtained during encoding) was compared between the two groups for both pain intensity and unpleasantness. RESULTS:Participants in both groups did not differ in terms of age and gender (real TMS = 27 years ± 9, 43% female; sham TMS = 25 years ± 4, 49% female; p > 0.64). The mnemonic bias related to pain intensity was similar in both groups (p = 0.83). However, the mnemonic bias related to pain unpleasantness was lower in the real TMS group (p = 0.04). CONCLUSIONS: Our results provide the first evidence that the STG, is causally involved in the formation of biased memories of pain unpleasantness.