Auditory mismatch negativity deficit is a robust neurophysiological biomarker of schizophrenia. Repetitive transcranial magnetic stimulation (rTMS) is a neuromodulation method and can be used to modulate excitability of specific brain cortical region. We hypothesize that MMN deficit of schizophrenia is related to inferior frontal gyrus (IFG) hypofunction, and this deficit can be improved by using rTMS to enhance IFG function. It is a randomized, double-blinded, sham-controlled clinical trial. Forty-eight schizophrenia patients with MMN deficits (mean amplitude at FCz \> -0.7 ㎶) will be recruited and then randomized at a 1:1 ratio to rTMS group and sham-stimulation group. Subjects in rTMS group will receive high frequency rTMS over IFG, while in the other group subjects will receive sham stimulation at IFG. Frameless stereotaxy navigation will be used to guide the rTMS coil to IFG. The primary outcome is the change of MMN mean amplitude at FCz after stimulation. We hypothesize that the change of MMN mean amplitude is significantly larger in rTMS group than in sham-stimulation group. Their cognitive function and clinical condition will be evaluated carefully before and after experiments.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
48
For one-session rTMS, 50 trains of stimulation are given. Each train is consisted of 4-second 10 Hz, 100% resting motor threshold TMS pulses. The inter-train interval is 26 seconds.
For one-session sham stimulation, 50 trains of stimulation are given. Each train is consisted of 4-second 10 Hz sham pulses. The inter-train interval is 26 seconds.
Department of Psychiatry, National Taiwan University Hospital
Taipei, Taiwan
RECRUITINGMismatch negativity (MMN)
Mismatch negativity is recorded by electroencephalography and elicited by auditory oddball paradigm in which tone duration deviants are used. MMN is the mean amplitude between 135 and 205 milliseconds after auditory stimuli recorded by electrode FCz.
Time frame: 1 day
Continuous performance test (CPT)
The undegraded 1-9 task and the 25% degraded 1-9 task are used. Sensitivity indices indicating the ability to discriminate target from non-target trials are calculated (d' for undegraded CPT and md' for degraded CPT).
Time frame: 1 day
Wisconsin Card Sorting Test (WCST)
Four indices of WCST are derived: perseverative errors, categories achieved, trials to complete first category, and conceptual level response.
Time frame: 1 day
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