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38. Increase in the excitability of spinal neural function during motor imagery about isometric opponens pollicis activity – F-wave study
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Society Proceedings / Clinical Neurophysiology 120 (2009) e147–e180
38. Increase in the excitability of spinal neural function during motor imagery about isometric opponens pollicis activity – Fwave study—Toshiaki Suzuki, Chieko Onigata, Makiko Tani (Kansai University of Health Sciences, Osaka, Japan) We analyzed the F-wave of left thenar muscles after stimulating the left median nerve at the wrist at rest and under touch and motor imagery conditions in 14 healthy subjects (7 males and 7 females; mean age: 30.8 years). In the rest condition, we tested the F-wave during relaxation. The touch condition is defined as holding the sensor of the pinch meter between the thumb and index finger. For the motor imagery condition, at first, subjects learn 50% MVC of isometrically contracting the opponens pollicis muscle with pinch meter and the next, the subjects were asked to imagine the contraction holding the sensor between the thumb and index finger. Persistence during the touch and motor imagery conditions was significantly higher than that observed at rest (paired t-test; p < 0:01Þ. The amplitude ratio of F/M during the motor imagery condition was significantly higher than that observed at rest (paired t-test; p < 0:01Þ. The amplitude ratio of F/M during the touch condition tended to increase compared with that observed at rest. It is suggested that a motor imagery about 50% MVC isometric contraction of opponens pollicis without overt motor output increases the excitability of spinal neural output to thenar muscles. doi:10.1016/j.clinph.2009.02.044
39. Cortical excitability in high-frequency repetitive transcranial magnetic stimulation for intractable neuropathic pain—Koichi Hosomi, Youichi Saitoh, Haruhiko Kishima, Masayuki Hirata, Satoru Oshino, Naoki Tani, Tetsu Goto, Takufumi Yanagisawa, Mohamed Ali, Shirou Yorifuji, Toshiki Yoshimine (Osaka University, Suita, Japan) The objective of this study was to assess the cortical excitabilities in patients with intractable neuropathic pain before and after repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex. In 16 patients with post-stroke pain in a hand and five healthy controls, the cortical excitability and visual analogue scale (VAS) were evaluated before and after 5 Hz-rTMS of the primary motor cortex corresponding to the painful hand. Resting motor threshold, amplitude of motor evoked potential, duration of cortical silent period, short interval intracortical inhibition and intracortical facilitation (ICF) were measured as the parameters of cortical excitability with single- or paired-pulse TMS method. Seven of 16 patients showed 30% pain reduction in VAS after rTMS (good responders). ICF in good responders was significantly lower than that in controls at baseline (p = 0.010). rTMS significantly increased ICF in good responders (p = 0.035). There were no significant differences and changes in the other parameters. Our findings suggested that restoration of the abnormal cortical excitability might be one of the mechanisms underlining the pain relief with rTMS in neuropathic pain. doi:10.1016/j.clinph.2009.02.045
40. Functional deficits in the extrastriate body area during observation of sports-related actions in schizophrenia—Hidehiko Takahashi (National Institute of Radiological Sciences, Chiba, Japan) Exercise and sports are increasingly being implemented in the management of schizophrenia. The process of action perception is as
important as that of motor execution for learning and acquiring new skills. Recent studies have suggested that body-selective extrastriate body area (EBA) is involved not only in static visual perception of body parts but also in the planning, imagination and execution of actions. However, functional abnormality of the EBA in schizophrenia has yet to be investigated. Using fMRI with a task designed to activate the EBA by sports-related actions, we aimed to elucidate functional abnormality of the EBA in schizophrenia. Twelve schizophrenia patients and 12 age–sex-matched control participants participated in the study. We examined brain activations during observation of context-congruent actions relative to context-incongruent actions by fMRI. Compared to controls, the patients demonstrated diminished activation in the EBA during observation of sports-related context-congruent actions. Furthermore, the EBA activation in patients was negatively correlated with the severity of negative and general psychopathology symptoms measured by the Positive and Negative Syndrome Scale. Dysfunction of the EBA might reflect a difficulty in representing dynamic aspects of human actions and might lead to impairments of simulation, learning and execution of actions in schizophrenia. doi:10.1016/j.clinph.2009.02.046
41. SNAP in the lower limbs – interside difference—Michiyuki Kawakami, Yoshihisa Masakado, Kanjiro Suzuki, Reon Abe, Tetsuo Ota, Akio Kimura, Meigen Liu (Keio University Tsukigase Rehabilitation Center, Shizuoka, Japan) The purpose of this study was to investigate a right–left difference in sensory nerve conduction parameter. We electrophysiologically studied the sural nerve, the superficial and deep peroneal nerve, the medial and lateral plantar nerve and the saphenous nerve in 80 neurologically healthy adults with a mean age of 35 years (range 21–59 years). Right–left difference of the latency to onset of the sensory action potential was normally-distributed , and the mean was more or less nought at all of six nerves. On the other hand, the ratio of the right to the left amplitude measured from negative to positive peak was not normally-distributed. In addition, the ratio of the smaller amplitude to the bigger amplitude less than 50% was not rare (10–35%). These findings indicate that right–left difference of the SNAP latency is reliable but a twofold side to side difference rule is not may statistically valid for side to side comparison of the amplitude in the lower limbs. doi:10.1016/j.clinph.2009.02.047
42. A new development of EEG-based brain–computer interface: For cursor control with calibration of suitable frequency band— Tomohiko Igasaki, Kana Fujiwara, Nobuki Murayama, Yuki Hayashida (Kumamoto University, Kumamoto, Japan) We have developed a new brain–computer interface (BCI) which enables a subject to move an arrow image on a screen in an intending direction. We recorded EEG activity from Pz area for 1024 ms just after the presentation of an arrow and calculated the band powers of 2–5 Hz, which were employed as a brain signal. The arrow image consisted of a left, right, up or down one, and each arrow was presented 10 times randomly in one session. Seven normal subjects (22–24 years old) were investigated. They were instructed to be strongly conscious when the arrow indicated the direction in which they intended to move the next. Four sessions a day were performed for 4–6 days. Although the band powers of 2–5 Hz were not effective as the brain signal for a few subjects, adjusting a frequency band
Society Proceedings / Clinical Neurophysiology 120 (2009) e147–e180
38. Increase in the excitability of spinal neural function during motor imagery about isometric opponens pollicis activity – Fwave study—Toshiaki Suzuki, Chieko Onigata, Makiko Tani (Kansai University of Health Sciences, Osaka, Japan) We analyzed the F-wave of left thenar muscles after stimulating the left median nerve at the wrist at rest and under touch and motor imagery conditions in 14 healthy subjects (7 males and 7 females; mean age: 30.8 years). In the rest condition, we tested the F-wave during relaxation. The touch condition is defined as holding the sensor of the pinch meter between the thumb and index finger. For the motor imagery condition, at first, subjects learn 50% MVC of isometrically contracting the opponens pollicis muscle with pinch meter and the next, the subjects were asked to imagine the contraction holding the sensor between the thumb and index finger. Persistence during the touch and motor imagery conditions was significantly higher than that observed at rest (paired t-test; p < 0:01Þ. The amplitude ratio of F/M during the motor imagery condition was significantly higher than that observed at rest (paired t-test; p < 0:01Þ. The amplitude ratio of F/M during the touch condition tended to increase compared with that observed at rest. It is suggested that a motor imagery about 50% MVC isometric contraction of opponens pollicis without overt motor output increases the excitability of spinal neural output to thenar muscles. doi:10.1016/j.clinph.2009.02.044
39. Cortical excitability in high-frequency repetitive transcranial magnetic stimulation for intractable neuropathic pain—Koichi Hosomi, Youichi Saitoh, Haruhiko Kishima, Masayuki Hirata, Satoru Oshino, Naoki Tani, Tetsu Goto, Takufumi Yanagisawa, Mohamed Ali, Shirou Yorifuji, Toshiki Yoshimine (Osaka University, Suita, Japan) The objective of this study was to assess the cortical excitabilities in patients with intractable neuropathic pain before and after repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex. In 16 patients with post-stroke pain in a hand and five healthy controls, the cortical excitability and visual analogue scale (VAS) were evaluated before and after 5 Hz-rTMS of the primary motor cortex corresponding to the painful hand. Resting motor threshold, amplitude of motor evoked potential, duration of cortical silent period, short interval intracortical inhibition and intracortical facilitation (ICF) were measured as the parameters of cortical excitability with single- or paired-pulse TMS method. Seven of 16 patients showed 30% pain reduction in VAS after rTMS (good responders). ICF in good responders was significantly lower than that in controls at baseline (p = 0.010). rTMS significantly increased ICF in good responders (p = 0.035). There were no significant differences and changes in the other parameters. Our findings suggested that restoration of the abnormal cortical excitability might be one of the mechanisms underlining the pain relief with rTMS in neuropathic pain. doi:10.1016/j.clinph.2009.02.045
40. Functional deficits in the extrastriate body area during observation of sports-related actions in schizophrenia—Hidehiko Takahashi (National Institute of Radiological Sciences, Chiba, Japan) Exercise and sports are increasingly being implemented in the management of schizophrenia. The process of action perception is as
important as that of motor execution for learning and acquiring new skills. Recent studies have suggested that body-selective extrastriate body area (EBA) is involved not only in static visual perception of body parts but also in the planning, imagination and execution of actions. However, functional abnormality of the EBA in schizophrenia has yet to be investigated. Using fMRI with a task designed to activate the EBA by sports-related actions, we aimed to elucidate functional abnormality of the EBA in schizophrenia. Twelve schizophrenia patients and 12 age–sex-matched control participants participated in the study. We examined brain activations during observation of context-congruent actions relative to context-incongruent actions by fMRI. Compared to controls, the patients demonstrated diminished activation in the EBA during observation of sports-related context-congruent actions. Furthermore, the EBA activation in patients was negatively correlated with the severity of negative and general psychopathology symptoms measured by the Positive and Negative Syndrome Scale. Dysfunction of the EBA might reflect a difficulty in representing dynamic aspects of human actions and might lead to impairments of simulation, learning and execution of actions in schizophrenia. doi:10.1016/j.clinph.2009.02.046
41. SNAP in the lower limbs – interside difference—Michiyuki Kawakami, Yoshihisa Masakado, Kanjiro Suzuki, Reon Abe, Tetsuo Ota, Akio Kimura, Meigen Liu (Keio University Tsukigase Rehabilitation Center, Shizuoka, Japan) The purpose of this study was to investigate a right–left difference in sensory nerve conduction parameter. We electrophysiologically studied the sural nerve, the superficial and deep peroneal nerve, the medial and lateral plantar nerve and the saphenous nerve in 80 neurologically healthy adults with a mean age of 35 years (range 21–59 years). Right–left difference of the latency to onset of the sensory action potential was normally-distributed , and the mean was more or less nought at all of six nerves. On the other hand, the ratio of the right to the left amplitude measured from negative to positive peak was not normally-distributed. In addition, the ratio of the smaller amplitude to the bigger amplitude less than 50% was not rare (10–35%). These findings indicate that right–left difference of the SNAP latency is reliable but a twofold side to side difference rule is not may statistically valid for side to side comparison of the amplitude in the lower limbs. doi:10.1016/j.clinph.2009.02.047
42. A new development of EEG-based brain–computer interface: For cursor control with calibration of suitable frequency band— Tomohiko Igasaki, Kana Fujiwara, Nobuki Murayama, Yuki Hayashida (Kumamoto University, Kumamoto, Japan) We have developed a new brain–computer interface (BCI) which enables a subject to move an arrow image on a screen in an intending direction. We recorded EEG activity from Pz area for 1024 ms just after the presentation of an arrow and calculated the band powers of 2–5 Hz, which were employed as a brain signal. The arrow image consisted of a left, right, up or down one, and each arrow was presented 10 times randomly in one session. Seven normal subjects (22–24 years old) were investigated. They were instructed to be strongly conscious when the arrow indicated the direction in which they intended to move the next. Four sessions a day were performed for 4–6 days. Although the band powers of 2–5 Hz were not effective as the brain signal for a few subjects, adjusting a frequency band