Association of anxiety with intracortical inhibition and descending pain modulation in chronic myofascial pain syndrome

Background: This study aimed to answer three questions related to chronic myofascial pain syndrome (MPS): 1) Is the motor cortex excitability, as assessed by transcranial magnetic stimulation parameters (TMS), related to state-trait anxiety? 2) Does anxiety modulate corticospinal excitability change...

Descripción completa

Detalles Bibliográficos
Autores: Vidor, Liliane Pinto, Torres, Iraci Lucena da Silva, Medeiros, Liciane Fernandes, Sarria, Jairo Alberto Dussán, Dall'Agnol, Letizzia, Deitos, Alícia, Brietzke, Aline Patrícia, Laste, Gabriela, Rozisky, Joanna Ripoll, Fregni, Felipe, Caumo, Wolnei
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Brasil
Institución:Universidade Federal do Rio Grande do Sul (UFRGS)
Repositorio:Repositório Institucional da UFRGS
Idioma:inglés
OAI Identifier:oai:www.lume.ufrgs.br:10183/110151
Acceso en línea:http://hdl.handle.net/10183/110151
Access Level:acceso abierto
Palabra clave:Ansiedade
Síndromes da dor miofascial
Estimulação magnética transcraniana
Dor crônica
Transcranial magnetic stimulation
Chronic pain
Noninvasive brain stimulation
Neuromodulation
Anxiety
Myofascial pain syndrome
Descripción
Sumario:Background: This study aimed to answer three questions related to chronic myofascial pain syndrome (MPS): 1) Is the motor cortex excitability, as assessed by transcranial magnetic stimulation parameters (TMS), related to state-trait anxiety? 2) Does anxiety modulate corticospinal excitability changes after evoked pain by Quantitative Sensory Testing (QST)? 3) Does the state-trait anxiety predict the response to pain evoked by QST if simultaneously receiving a heterotopic stimulus [Conditional Pain Modulation (CPM)]? We included females with chronic MPS (n = 47) and healthy controls (n = 11), aged 19 to 65 years. Motor cortex excitability was assessed by TMS, and anxiety was assessed based on the State-Trait Anxiety Inventory. The disability related to pain (DRP) was assessed by the Profile of Chronic Pain scale for the Brazilian population (B:PCP:S), and the psychophysical pain measurements were measured by the QST and CPM. Results: In patients, trait-anxiety was positively correlated to intracortical facilitation (ICF) at baseline and after QST evoked pain (β = 0.05 and β = 0.04, respectively) and negatively correlated to the cortical silent period (CSP) (β = -1.17 and β = -1.23, respectively) (P <0.05 for all comparisons). After QST evoked pain, the DRP was positively correlated to ICF (β= 0.02) (P < 0.05). Pain scores during CPM were positively correlated with trait-anxiety when it was concurrently with high DRP (β = 0.39; P = 0.02). Controls’ cortical excitability remained unchanged after QST. Conclusions: These findings suggest that, in chronic MPS, the imbalance between excitatory and inhibitory descending systems of the corticospinal tract is associated with higher trait-anxiety concurrent with higher DRP.