Functional imaging of the brain provides information on the functional activation during motor tasks. The physiological roles of the frontomesial cortex during various unimanual motions have been investigated using the technique. It has been reported that frontomesial cortex contains at least four distinct areas: pre-SMA (supplementary motor area); SMA-proper; RCZ (rostral cingulate zone); CCZ (caudal cingulate zone). However, the activations of these areas during bimanually coordinated motions have not been fully investigated by the functional imaging studies. In the present study we analyzed the influence of bimanual coordination on activations of these four areas using functional magnetic resonance imaging. The subjects were 7 healthy right-handed volunteers, aged 22 to 42 (mean 30) years. They performed 2 bimanual motor tasks requiring the repetitive closing and opening of both fists: simultaneous agonistic movement of both hands (task A); simultaneous antagonistic movement of both hands (task B). In task A, the subjects simultaneously made fists with both hands and then simultaneously opened them, whereas in task B they made a fist with one hand while simultaneously opening the contralateral fist, and then the reverse. The only difference between tasks A and B was the timing of the closing and opening of the contralateral fists. Each task consisted of alternating periods of 20 seconds of rest (resting period) and 20 seconds of motor execution (activation period). The movements were performed in accordance with the sound of the MR machine. The functional images of bilateral sagital slices were obtained by gradient-echo and echo-planar sequences. We counted and compared the total number of activated pixels between the tasks. SMA proper was activated in both tasks for almost all the subjects. The activation during task B was more pronounced than task A. The number of activated pixels in task A significantly correlated to that in task B (r=0.9). SMA proper activation showed no significant right-left difference in both tasks. Other areas, however, were inconsistently activated across the subjects. None of the subjects showed activation of RCZ. Higher activation in RCZ and pre-SMA has been reported to be associated with more complex, sequential, self-paced movement; cognitive process of motor performance; preparation or selection of motor response. Therefore, inconsistent activation of the areas in the present study was compatible with other reports, because the motor tasks consisted of simple, repetitive, externally paced motions. In contrast some studies showed that SMA proper closely related to motor execution. Our findings suggested a more important role of the SMA proper in the control of alternating bimanual movement used in the present study. Further study, however, is necessary to clarify whether this finding is also applicable to a more complex, sequential bimanual motion.

View full abstract

We took X-ray photos (XP) of the oral cavity and neck parts of 210 patients, who were suspected of having eating and swallowing disorders and had been examined with VF (videofluorography). XP (scout roentgenogram) were taken laterally both before and after the patients swallowed contrast medium. We compared findings of VF and those of XP. The results showed that the XP diagnosis of aspiration was reliable in terms of sensitivity, specificity and the rate of misdiagnosis. As we used lateral XP, it was easy to identify the esophagus and trachea. 2 XP taken before and after patients' swallowing contrast medium enabled us to distinguish aspiration from calcification around the larynx, which otherwise would have been difficult, resulting in easier confirmation of aspiration. We could safely conclude that the X-ray diagnosis was useful in screening dysphagia.

View full abstract

The purpose of this study was to investigate the reliability of spectral electromyographic fatigue analysis. Fifteen healthy women were studied during a trunk holding test using surface electromyographic power spectrum analysis. Median frequency (MF) and mean power frequency (MPF) were calculated using spectrum analysis program, and the decreasing rate of MF and MPF were evaluated. The negative MF slope and MPF slope were closely correlated with the holding time, however the body weights were not correlated. These suggested that the spectral electromyographic fatigue analysis was useful to evaluate the trunk endurance.

View full abstract

A 68-year-old male suffering from r-thalamic hemorrhage associated with a ventricular rupture was given total parenteral nutrition (TPN) containing Mn at 20μmol (1.10mg)/day for 63 days, due to a lack of improvement following hematoma aspiration surgery. Even 4 weeks after cessation of TPN, severe rigidity, akinetic mutism and other problems persisted. A characteristic pattern on T 1-weighted MRI, including an increased signal from the basal ganglia and deep white matter of both hemispheres, and elevated serum Mn levels, suggested Parkinson's syndrome due to Mn intoxication. Levodopa, Amantadine hydrochloride, and a chelating agent (calcium disodium edetate) effectively improved his conditions, including the rigidospasticity, akinesia, speech deficit, and ADL. After 3 months treatment with anti-Parkinsonism agents and hemiplegic rehabilitation, the patient regained the ability to walk and specific findings on MRI also disappeared. More attention should be paid to the extrapyramidal side-effects of long-term intravenous administration of Mn.

View full abstract