Biomedical subjects

Masaru Yokoe

Publications and source records attributed to Masaru Yokoe.

6 recordsLinked to original sources

PubMed2006

The "cross" signs in patients with multiple system atrophy: a quantitative study.

Patients with multiple system atrophy (MSA) may show the "cross" sign in the pontine base that has been considered as an expression of the degeneration of pontine neurons and transverse pontocerebellar fibers. However, correlations between pontine base atrophy and existence of "cross" sign have not been fully investigated. The authors studied 68 patients with MSA (47 MSA-C [predominantly cerebellar ataxia], 21 MSA-P [predominantly parkinsonism], mean [+/-SD ] 58.7 +/- 10.9 years). T1-weighted (T1W) sagittal and axial images and T2-weighted (T2W) axial images were obtained for all patients and controls. To measure the areas of pontine basis and cerebellar vermis, the authors used midsagittal T1W images and analyzed a bit map transformed on a computer. They classified atrophy in the pontine base into 3 grades. There is significant correlation between atrophies of pontine base and existence of the cross sign. All patients with a smaller area of pontine base 2 standard deviations below those of normal controls had the cross sign. This supports that existence of the cross sign depends only on the extent of pontine base atrophies.

Adult↗

PubMed2004

Quantitative magnetic detection of finger movements in patients with Parkinson's disease.

To develop a new measurement tool for quantitatively detecting the finger movement of a patient with Parkinson's disease (PD), we designed a magnetic sensing system consisting of a magnetic induction coil, a sensing coil, and a circuit unit. The sensing coil detects the inducted magnetic field that varies with the distance between the two coils, and the detected signals are demodulated in the circuit unit in order to obtain the variation voltage from the oscillation frequency. To obtain a coefficient for converting voltage to distance, we measured the output voltages for seven fixed finger positions of 12 normal volunteers. The voltage differences corresponding to the finger movement in 20 PD patients, six age-matched controls, and 12 normal volunteers were then recorded for 30s. To investigate the velocity and acceleration of the finger movement, we calculated their waveforms from the measured displacement waveform. We also detected the main frequency of the tapping rhythm by using a fast Fourier transform (FFT). The averaged amplitude of each waveform decreased with the disorder in the Hoehn-Yahr (HY) stage, while the averaged tapping frequency of PD patients did not have any correlation with this stage. It can be concluded that this magnetic sensing system can assess finger movement quantitatively.

Adult↗

PubMed2004

A pitfall in MRI.

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False Negative Reactions↗

PubMed2004

[A clinical trial of creatine monohydrate in muscular dystrophy patients].

To investigate the effects of creatine monohydrate on muscle performance and cognitive functions in muscular dystrophy patients, we made an open trial. Twenty-nine individuals, including 14 myotonic dystrophy (DM), seven facioscapurohumeral muscular dystrophy (FSHD), two limb-girdle muscular dystrophy and six healthy volunteers, were enrolled in this study and 27 participants completed it. All participants took creatine 20g/day for an initial week and 5g/day for successive eight weeks. Somatotonic measurements, global subjective assessment, muscle performance, cardiopulmonary function, cognitive function, laboratory studies and magnetic resonance spectroscopy (MRS) were evaluated at both pre and post examination. Subjective improvements were reported from twelve individuals. Contrary adverse effects were also complained from ten individuals, although all these problems were not serious. Quantitative muscle power was slightly but significantly increased in the patients and the number of the patients who failed to complete cycle ergometer test was decreased. Phosphocreatine concentrations of left calf muscle were not different between pre and post trial examination. No obvious changes were detected in cardiopulmonary assessment, cognitive function and laboratory date. Creatine has certain expectance for muscular dystrophy patients in motor performance. The effect may be achieved not only by increase of energy buffer, because clinical improvements were observed in our study nevertheless no increase was detected in phosphocreatine concentration. The usage of creatine should be managed under medical monitoring since ideal protocol has not yet been established and adverse effects can not be ignored.

Activities of Daily Living↗

PubMed2002

[A case of Satoyoshi syndrome complicating marginal gingivitis of the mandible and dislocation of the temporomandibular joint].

Satoyoshi syndrome is a very rare disorder, characterized by progressive painful intermittent muscle spasms beginning in adolescence. Universal alopecia, diarrhea, amenorrhea and bony deformities are also cardinal features of this syndrome. Skeletal abnormalities, such as joint deformity, epiphysial destruction and retarded growth, are observed in approximately half of patients. However, no bony changes have previously been reported in the region of the head. We present here a male patient with Satoyoshi syndrome. Muscle cramps began in the lower extremities when he was 13 years old, and gradually spread. At the age of 17 years, masticatory muscle cramps made it difficult to eat and speak fluently, and were considered a cause of malacia in this patient. Finally, recurrent severe cramps in the masseter muscles caused marginal gingivitis of the mandible, necessitated extraction of the teeth and caused dislocation of the temporomandibular joint. After treatment with dantrolen sodium at doses up to 150 mg/day, painful spasm decreased significantly. Since masticatory muscles can cause significant stress to the teeth and the temporomandibular joint, sufficient attention should be paid to the oral region to avoid complications in patients with Satoyoshi syndrome.

Adolescent↗

PubMedDate not supplied

[A case of Duchenne muscular dystrophy complicated by thrombotic thrombocytopenic purpura].

We experienced a patient with Duchenne muscular dystrophy (DMD) complicated by thrombotic thrombocytopenic purpura (TTP). This patient exhibited abrupt high fever, renal dysfunction and thrombocytopenia from February 2, 2002. Hemolysis was also indicated by indirect dominant hyperbilirubinemia, although hemoglobin was only slightly decreased. No central nervous system signs and symptoms were detected. TTP was suggested by these findings and confirmed by decreased activity (21%) of von Willebrand factor cleaving protease activity. Plasma exchange was performed for 4 days from February 5, and enabled recovery. Thrombosis, such as cerebral and lung infarction, has occasionally been seen in DMD. Recently, several findings associating muscle degeneration with hypercoagulation have been reported, for example, a strong correlation between serum CK level and FDP. In seven cases of DMD with pulmonary infarction, transient elevation of serum CK was detected prior to LDH elevation. However, there have been no reports of TTP in DMD patients. Since serum CK was not elevated during our patient's clinical course, it is unlikely that muscle degeneration played a role in TTP in this patient. It should be noted that endothelial abnormalities have been reported in DMD, since endothelial injury is considered a fundamental factor in TTP.

ADAM Proteins↗