Alteration of cortical excitability in patients with fibromyalgia

Abstract

We assessed cortical excitability and intracortical modulation systematically, by transcranial magnetic stimulation (TMS) of the motor cortex, in patients with fibromyalgia. In total 46 female patients with fibromyalgia and 21 normal female subjects, matched for age, were included in this study. TMS was applied to the hand motor area of both hemispheres and motor evoked potentials (MEPs) were recorded for the first interosseous muscle of the contralateral hand. Single-pulse stimulation was used for measurements of the rest motor threshold (RMT) and suprathreshold MEP. Paired-pulse stimulation was used to assess short intracortical inhibition (SICI) and intracortical facilitation (ICF). Putative correlations were sought between changes in electrophysiological parameters and major clinical features of fibromyalgia, such as pain, fatigue, anxiety, depression and catastrophizing. The RMT on both sides was significantly increased in patients with fibromyalgia and suprathreshold MEP was significantly decreased bilaterally. However, these alterations, suggesting a global decrease in corticospinal excitability, were not correlated with clinical features. Patients with fibromyalgia also had lower ICF and SICI on both sides, than controls, these lower values being correlated with fatigue, catastrophizing and depression. These neurophysiological alterations were not linked to medication, as similar changes were observed in patients with or without psychotropic treatment. In conclusion, fibromyalgia is associated with deficits in intracortical modulation involving both GABAergic and glutamatergic mechanisms, possibly related to certain aspects of the pathophysiology of this chronic pain syndrome. Our data add to the growing body of evidence for objective and quantifiable changes in brain function in fibromyalgia.

Corticomotor control of deep abdominal muscles in chronic low back pain and anticipatory postural adjustments

“…In fact, SICI circuits are influenced by horizontal cortico-cortical connections and sensory afferents (Reis et al 2008). Any pain-related alteration of sensory afferents and their integration may thus alter SICI mechanisms, as already suggested in very chronic painful conditions where SICI was shown to be decreased (Salerno et al 2000;Schwenkreis et al 2000;Schwenkreis et al 2003;Eisenberg et al 2005;Lefaucheur et al 2006;Mhalla et al 2010;Schwenkreis et al 2010). The postural defects observed in most LBP patients may have led to such alteration of sensory transduction.…”

Into the Island: A new technique of non-invasive cortical stimulation of the insula

“…One could hypothesize that high-frequency rTMS to the PICO might change altered central sensitization related to chronic neuropathic pain [6,12,13], thus leading to pain relief.…”

Influência Do Gênero, Fases Do Ciclo Menstrual E Uso De Anticoncepcional Na Excitabilidade Cortical De Indivíduos Saudáveis

“…Dentre estes o gênero, (15) as fases do ciclo menstrual e o uso de anticoncepcional podem ser destacados. (16)(17)(18) A amostra foi constituída por indivíduos que se auto relatavam saudáveis com idade maior ou igual a 18 anos. Os critérios de exclusão do estudo foram: (i) evidência clínica de lesões encefálicas; (ii) gravidez; (iii) histórico de distúrbios psiquiátri-cos ou de crise convulsiva; (iv) uso de implantes metálicos na cabeça ou marcapasso cardíaco.…”