Past Issues

Analgesic Effect of Repetitive Transcranial Magnetic Stimulation on Medically Unexplained Pain in Patients with Medication-resistant Depression

Cheng-Ta Li, Wei-Chen Lin, Mu-Hong Chen, Tung-Ping Su, Ya-Mei Bai, Jen-Chuen Hsieh

Objectives: Medically unexplained symptoms of pain (MUS-pain) are common
in patients with depression and can worsen clinical outcomes. High-frequency
repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral
prefrontal cortex (DLPFC) has been proven effective for managing treatment-resistant
depression and chronic pain, and might relieve chronic MUS-pain. But
whether left prefrontal rTMS has analgesic effects on MUS-pain remains unclear.
Methods: A randomized sham-controlled rTMS study (10-Hz, 1600 pulses/session,
10 sessions) was conducted for 2 weeks to determine whether rTMS is effective
in treating medication-resistant depressed patients with MUS-pain (n = 24).
Furthermore, in another left prefrontal 10-Hz rTMS study originally targeting at
antidepressant effects, we applied a 10-session rTMS therapy in patients with depression
and MUS-pain (n = 16) and those with depression alone (n = 10) and
followed them for another three months, in order to investigate the interaction between
painful and depressive symptoms. Results: In this study, we totally recruited
40 patients with MUS-pain and 10 patients without MUS-pain. We found that a
two-week navigated 10-Hz rTMS over the left DLPFC was signifi cantly more effective
in treating MUS-pain than sham rTMS (p < 0.05), and the analgesic effects
of the treatment was independent of its antidepressant effects. We also found a
higher rate of relapse for depression in patients whose MUS-pain responded poorly
to rTMS. Conclusion: Our report has identifi ed an rTMS analgesic effect for
MUS-pain in depressed patients. Our data strongly indicate that MUS-pain should
be aggressively identifi ed in patients with major depressive disorder because of its
detrimental effect on treatment outcome.
Key Word depression, transcranial magnetic stimulation (TMS), positron emission tomography (PET), somatoform disorders
Editorial Committe, Taiwanese Journal of Psychiatry
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