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The forearm rotation changes sensory inputs to the central nervous system, thereby providing orientation of the hand for grasping an object. Electrical activities of the muscles, induced by transcranial magnetic stimulation to the brain, i.e., motor evoked potentials (MEPs), are used for estimation of the excitability of motor neurons in the brain and spinal cord. It is well known that rotational positioning of the forearm influences MEPs of forearm muscles through modulation of excitability in the central nervous system. In the present study, we investigated whether such a posture-dependent change of MEPs could be found in upper arm and intrinsic hand muscles at three different rotational forearm positions: the most internal (pronation), neutral, and most external (supination) positions of rotation. MEPs were simultaneously recorded from the four muscles, biceps brachii (BB), triceps brachii (TB), abductor digiti minimi (ADM), and abductor pollicis brevis (AbPB). MEP amplitudes and latencies in BB, TB and ADM were significantly larger and shorter, respectively, in supination compared to the values in other positions. By contrast, MEP of AbPB in supination was lower in amplitude and longer in latency. Importantly, muscle lengths of TB, ADM and AbPB are constant in any rotational forearm positions, excluding the possibility of the muscle-length dependent change of spinal reflex. Therefore, these results might be attributable to the posture-dependent modulation of the motor cortex activity for the upper limb. The motor cortex probably changes the control strategy for the upper limb muscles in accordance with the sensory input from the forearm. motor evoked potentials; forearm rotation; hand and arm; motor cortex; α -motoneuron

Hemispatial neglect is a common disorder that can occur after a lesion in the right hemisphere. Its main characterization is the difficulty in processing visual stimuli emanating from the space contralateral to the lesion. Pencil and paper tests (such as target cancellation, line bisection, or drawing copy) are used to diagnose neglect. We propose using virtual reality technology and haptic force feedback to enhance pencil and paper tests. Our system can track the patients' eye-gaze and their hand movements. Also, the efficiency of several techniques used to decrease the neglect in different sensory spaces are investigated.

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Our objective is to develop and test a system for diagnosis and rehabilitation of patients with hemispatial neglect. The system consists of a 3D-haptic virtual world seen through stereo shutter-glasses. Patients interact by manipulating a haptic interface. The software adapts the virtual world accordingly to haptic interface and eye tracking feedback. Offline analysis is possible by reviewing recorded data. Observations made during experimentations with hemiplegics patients and future works with hemispatial neglect patients are discussed.

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The purpose of this study is to examine the morphological and kinematical changes of the uterus induced by electrical stimulation applied to the skin just above the second and fourth posterior sacral foramens (sacral surface electrical stimulation [ssES]) in 26 healthy subjects. Out of them, eight subjects who had severe pain subjectively during every menstruation received ssES just in menstruation. Morphological and functional changes of the uterus were examined by using T2-weighted magnetic resonance (MR) imaging and T1-weighted MR cinematography, respectively. Cyclic electrical stimulation for 15 min with 5 sec ON and 5 sec OFF was applied just before MR scanning. A decrease in thickness of the muscular layer of the uterus was observed in every subject after ssES for 15 min and was significant as compared with the thickness before ssES. Periodic uterine movement during menstruation was observed in the subjects with severe menstrual pain in MR cine and the power spectrum analysis of the movement showed a marked decrease in peak power and frequency after ssES treatment. We conclude that ssES causes a reduction of static muscle tension of the uterus in all menstrual cycle periods and suppression of uterine peristalsis during menstruation in the subjects with severe menstrual pain. Possible neural mechanisms for these static and dynamic effects of ssES on the uterus at spinal level are discussed.sacral surface electrical stimulation; uterus; MRI; neuromodulation © 2006 Tohoku University Medical PressThe contractile component of the uterine wall is the myometrium which is composed of smooth muscles. The myometrium regulates tension of the uterine wall and peristaltic movements of the uterus under control of the autonomic nervous system. The pelvic organs are controlled by the hypogastric nerves (sympathetic) and pelvic nerves (parasympathetic) which are, in general,