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A 37-year-old man with a right transfemoral amputation suffered from severe phantom limb pain (PLP). After targeting the affected supplementary motor complex (SMC) or primary motor cortex (PMC) using a neuro-navigation system with 800 stimuli of 1 Hz repetitive transcranial magnetic stimulation (rTMS) at 85% of resting motor threshold, the 1 Hz rTMS over SMC dramatically reduced his visual analog scale (VAS) of PLP from 7 to 0. However, the 1 Hz rTMS over PMC failed to reduce pain. To our knowledge, this is the first case report of a successfully treated severe PLP with a low frequency rTMS over SMC in affected hemisphere.
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To delineate whether cortical plasticity induced by continuous theta burst stimulation (cTBS) differed according to catechol-O-methyltransferase (
Eighteen healthy older volunteers (mean age 73.78±5.04; 12 females and 6 males) were recruited. Volunteers randomly assigned in either a sham-first or real cTBS first group participated in two separate TMS visits with at least a 2-day wash-out period. Genotyping was carried out at baseline by a separate researcher who was blinded. cTBS was delivered in a hot spot over M1 at an active motor threshold of 80%. Motor evoked potentials (MEPs) were obtained at 120% of the resting motor threshold before and after sham/cTBS.
The relative MEP to baseline was significantly decreased 0 and 10 minutes post-stimulation and increased 40 minutes post-stimulation, as compared with the sham condition. Immediately after cTBS, the Val/Val group had a significantly reduced relative MEP value, as compared with the MET carrier group.
In healthy older persons, cTBS-induced motor plasticity was reduced in the COMT Val/Val group as compared with the 158Met carrier group.
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Clinical presentation of supplementary motor area (SMA) syndrome includes complete akinesia of the contralateral side of the body and mutism, with secondary recovery of neurologic deficit. Multi-joint coordination is frequently impaired following the development of a brain lesion and is generally restricted by abnormal patterns of muscle activation within the hemiparetic limb, clinically termed muscle synergies. However, no work to date has confirmed this observation with the aid of objective methods, such as gait analysis, and the development of reflex pattern has not been suggested as a possible cause. We describe two unusual cases of flexor synergy after tumor resection of SMA lesions.
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Method: Ten subjects were investigated using either 20 Hz or 1 Hz rTMS. To reduce inter-individual variability, we explored same subject in one week interval with different frequency. TMS was conducted with intensity of 90% of motor threshold. The effect of rTMS with EMG amplitude evoked in First Dorsal Interossei by TMS. Test motor evoked potentials were evaluated with intensity of 110% of motor threshold before rTMS, during the interval and immediately, 5 minutes, 20 minutes after the end of train.
Results: The analysis showed a significant decrease of cortical excitability after 1 Hz rTMS and an increase after 20 Hz rTMS. In low-frequency, Motor Evoked Potential (MEP) amplitude decreased quickly after initial 300 pulses stimulation. In high-frequency, there were some variation of individual MEP in the response to rTMS. The changes of MEP amplitude after 1200 stimulation continued until 20 minutes.
Conclusion: These results provided basic evidence of rTMS for modulation of cortical excitability and could be further applied in patients group. (J Korean Acad Rehab Med 2003; 27: 922-927)
Objective: To investigate the clinical usefulness of the motor cortex mapping using transcranial magnetic stimulation (TMS) in stroke patients.
Method: Five stroke patients were studied. A piece of cloth which marked at 1 cm interval was fixed on the patient's head. Motor cortex mapping for abductor pollicis brevis muscles (APB) was performed with a butterfly coil or with a round coil if motor cortex mapping was impossible.
Results: Ipsilateral motor pathways were discovered from the unaffected motor cortex to the affected APB in patient 1. This patient showed delayed latency and low amplitude of ipsilateral motor evoked potentials (MEP) that seems to be evoked from the descending motor pathway rather than the corticospinal tract. In patient 2 and 3, contralateral motor pathways traveled from the affected hemisphere to the affected APB. The short latency and high amplitude of MEPs seems to be attributed to the corticospinal tract. In patient 4, no MEP was evoked by any hemisphere or magnetic stimulator. We believe that the affected APB had no motor pathway, and it correlated well with the poor motor function of her hand. In patient 5, contralateral pathways from the affected hemisphere to the affected APB were present. In this patient, the parameters of the motor cortex map such as the amplitude of MEP, the number of MEP evoked site, and the excitatory threshold were improved after 2 months, which correlated well with clinical improvement.
Conclusion: Motor cortex mapping using TMS is clinically useful for the evaluation of the characteristics of motor pathways and the change of motor cortex excitability in stroke patients.
The aim of this study is to investigate the mechanism of motor recovery using both functional Magnetic Resonance Imaging (fMRI) and Transcranial Magnetic Stimulation (TMS) in a patient with hemorrhagic contusion on the right basal ganglia area. Functional MRI showed that the left primary sensorimotor cortex and the supplementary motor area were activated when the right fingers performed the flexion-extension exercise. On the other hand, the bilateral primary sensorimotor cortex and the left premotor area were activated with the excerise of left hand. Brain mapping for both abductor pollicis brevis muscles (APB) using TMS revealed that ipsilateral motor evoked potentials (MEPs) were obtained at left APB. Ipsilateral MEPs of left APB showed delayed latency and lower amplitude compared to that of right APB when stimulated at the left motor cortex. We concluded that ipsilateral motor pathway from undamaged motor cortex seems to contribute to the motor recovery in this patient and combining TMS with fMRI may provide a powerful tool for investigating the mechanism of motor recovery.
Objective: To investigate the characteristics of the motor cortex map for abductor pollicis brevis muscle (APB) using transcranial magnetic stimulation (TMS) in normal subjects.
Method: Ten adults without neurological disorder were studied. A piece of cloth which marked at 1 cm interval was fixed on the head of the subject. The motor cortex mapping for APB was done with butterfly magnetic stimulator, and then with round magnetic stimulator.
Results: The average optimal scalp position for left APB was located on lateral 6.2 cm, anterior 0.1 cm from Cz and that for right APB was located on lateral 6.0 cm, anterior 0.1 cm from Cz when stimulated with butterfly magnetic stimulator. The differences between hemispheres were less than 1 cm in the location of optimal scalp position and less than 10% in excitatory threshold (ET) irrespective of magnetic stimulator. The ipsilateral motor evoked potential (MEP) was not evoked in all subjects. The ET when stimulated with butterfly magnetic stimulator was higher to that when stimulated with round magnetic stimulator.
Conclusion: We conclude that TMS using butterfly and round magnetic stimulator is useful for the motor cortex mapping.
Objective: To investigate the optimal condition for activation of motor cortex by electrical stimulation of forelimb in rat.
Method: Eleven adult rats (Sprague-Dawley rat) were studied, each of which was anesthetized and craniotomized. While the electrical stinulation was given on the contralateral forelimb of the fixed rat at stereotaxic frame, the evoked potential (EP) was obtained at the motor cortex of rat brain. The conditions of electrical stimulation were changed with 5 kinds of frequencies (1, 3, 5, 10, 15 Hz), 4 kinds of stimulus intensities (1, 3, 5, 7 mA) and 3 kinds of pulse widths (100, 200, 300μsec).
Results: The peak latencies of EPs in the motor cortex were significantly decreased and the amplitudes were significantly increased along with the decrement of stimulus frequency and the increment of stimulus intensity. The peak latencies and amplitudes of EPs were not significantly changed by stimulus pulse widths.
Conclusion: The motor cortex of rat was more activated with lower frequency and higher intensity regardless of pulse width in the given condition of electrical stimulation in this study. Key_words: 전기적 자극, 운동 피질, 유발전위, Electrical stimulation, Motor cortex, Evoked potential
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