Page 223 - MEGIN Book Of Abstracts - 2023

entity from migraine as suggested by the diagnostic thermal pain sensitivity to changes in brain structure.
criteria. However, the neural correlates of mechanical pain
sensitivity remain to be clarified through investigation
RECENT FINDINGS A recent magnetoencephalo- of direct neural activities on the resting-state cortical
graphic study from our group enrolled patients with oscillation and synchrony.
"strict-criteria" TTH (i.e., absence of any migraine
characteristics and associated symptoms) to compare METHODS We recorded the resting-state magnetoen-
the somatosensory excitability with patients with mi- cephalographic (MEG) activities of 27 healthy individu-
graine and controls. This study provided evidence that als and 30 patients with episodic migraine (EM) and
TTH and migraine differ in excitability profiles and the analyzed the source-based oscillatory powers and
measurement of preactivation excitability was able to functional connectivity at 2 to 59 Hz in pain-related
discriminate TTH from migraine. Earlier studies on brain cortical regions, which are the bilateral anterior cingu-
excitability of TTH yielded negative findings or a com- late cortex (ACC), medial orbitofrontal (MOF) cortex,
mon change shared with migraine. Future studies using lateral orbitofrontal (LOF) cortex, insula cortex, primary
strict diagnostic criteria to avoid the unwanted interfer- somatosensory cortex (SI), primary motor cortex (MI),
ence from migraine comorbidity may help decipher and posterior cingulate cortex (PCC). The mechanical
the "true" pathophysiology of TTH, which may pave the punctate pain threshold (MPPT) was obtained at the
way to a TTH-specific brain signature and treatment. supraorbital area (the first branch of the trigeminal
nerve dermatome, V1) and the forearm (the first tho-
Keywords: Brain excitability, Magnetoencephalography racic nerve dermatome, T1) and further correlated with
(MEG), Migraine, Neurophysiology, Somatosensory gating, MEG measures.
Tension-type headache (TTH)
RESULTS The MPPT is inversely correlated with the
Current pain and headache reports (2021), Vol. 24, No. 12 resting-state relative powers of gamma oscillation in
(33415543) (1 citation) healthy individuals (all corrected P < 0.05). Specifically,
inverse correlation was noted between the MPPT at V1
and gamma powers in the bilateral insula (r = - 0.592
Individual pain sensitivity is associated with [left] and - 0.529 [right]), PCC (r = - 0.619 and - 0.541) and
resting-state cortical activities in healthy MI (r = - 0.497 and - 0.549) and between the MPPT at T1
individuals but not in patients with migraine: a and powers in the left PCC (r = - 0.561) and bilateral MI
magnetoencephalography study (2020) (r = - 0.509 and - 0.520). Furthermore, resting-state func-
tional connectivity at the delta to beta bands, espe-
Hsiao, Fu-Jung; Chen, Wei-Ta; Liu, Hung-Yu; Wang, Yen- cially between frontal (MOF, ACC, LOF, and MI), parietal
Feng; Chen, Shih-Pin; Lai, Kuan-Lin; Pan, Li-Ling Hope; (PCC), and sensorimotor (bilateral SI and MI) regions,
Wang, Shuu-Jiun showed a positive correlation with the MPPT at V1 and
T1 (all corrected P < 0.05). By contrast, in patients with
Brain Research Center, National Yang-Ming University, Taipei, EM, the MPPT was not associated with resting-state
Taiwan. [email protected]; Department of Neurology, cortical activities.
Neurological Institute, Taipei Veterans General Hospital, Tai-
pei, Taiwan; Department of Neurology, Neurological Institute, CONCLUSIONS Pain sensitivity in healthy individuals
Taipei Veterans General Hospital, Taipei, Taiwan. sjwang@ is associated with the resting-state gamma oscillation
vghtpe.gov.tw and functional connectivity in pain-related cortical
regions. Further studies must be conducted in a large
BACKGROUND Pain sensitivity may determine the risk, population to confirm whether resting-state cortical
severity, prognosis, and efficacy of treatment of clinical activities can be an objective measurement of pain
pain. Magnetic resonance imaging studies have linked sensitivity in individuals without clinical pain.

 ontents  Index 202
C