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Hiroshi Shigeto

Publications and source records attributed to Hiroshi Shigeto.

12 recordsLinked to original sources
PubMed2006

Functional network of the basal ganglia and cerebellar motor loops in vivo: different activation patterns between self-initiated and externally triggered movements.

The basal ganglia and cerebellar loops are known to participate differently in self-initiated (SI) and externally triggered (ET) movements. However, no previous neuroimaging studies have illustrated functional organization of these loops in vivo. Here, we aimed to functionally visualize these loops during motor execution using functional magnetic resonance imaging (fMRI) with structural equation modeling (SEM). Twelve normal subjects (24-29 years old) were scanned while performing five different frequencies of sequential left finger movements using either SI or ET movements. Random effect analysis combined with a parametric approach revealed a significant positive linear dependence of cerebral activation upon movement rate in the right Put, GPi, VL, SMC and SMA during SI tasks. During ET tasks, significant positive linear relationships were found in the right SMC, VPL, left CB and DN, whereas tendency for linear relationships was seen in the right PMv. SEM further showed significant interactions within the right basal ganglia-thalamo-motor loop during SI tasks. In contrast, there were significant interactions within the entire right cerebral hemisphere-left cerebellar loop involving CB, DN, VPL, PMv and SMC during ET tasks. Therefore, our modeling approach enabled identification of different contributions of the motor loops of basal ganglia and cerebellum to SI and ET tasks during motor execution.

Adult↗
PubMed2006

[A case of adult-onset Sydenham chorea accompanied with psychiatric symptoms].

We report a 56-year-old man with adult-onset Sydenham chorea. Since January 2003, he had often troubled other persons, and in October 2003, following an episode of fever in August of the same year, he noticed left shoulder joint pain and involuntary movements of his limbs, especially on the left side. These involuntary movements gradually worsened and he became unable to converse due to psychiatric symptoms. On admission, neurological examination revealed dementia, emotional incontinence, abnormal behavior and chorea in four limbs. Brain MRI disclosed swelling of bilateral caudate heads that was more marked on the right side. Hypermetabolism in bilateral caudate nuclei, especially on the right, was found on FDG-PET study, which was compatible with his left side-dominant chorea and might reflect inflammation as a nature. A gallium scintigram demonstrated excess accumulations in the plural joints of his extremities, which gradually decreased in parallel with joint pain relief. The present case was diagnosed as Sydenham chorea, because of the presence of arthritis, chorea, fever, increased erythrocyte sedimentation rate and elevated CRP. We believe that this is a first report of adult-onset Sydenham chorea accompanied with psychiatric symptoms.

Chorea↗
PubMed2006

[Fibromuscular dysplasia of the basilar artery presenting as cerebral infarction in a young female].

We reported a 20-year-old woman with fibromuscular dysplasia (FMD) of the basilar artery presenting multiple cerebral infarctions. A sudden onset of consciousness disturbance and right hemiparesis was experienced. A neurological examination on day 2 revealed an absence of light and corneal reflexes on the left side, homonymous left upper quadrant anopsia and right hemiparesis with Babinski sign: she was also somnolent. On head MRI, multiple high signal intensity lesions were seen in the right occipital lobe, bilateral thalami and left pons on T2- and diffusion weighted images. Brain angiogram revealed the string of beads sign of the basilar artery, suggesting FMD. Neurological deficits gradually improved in the 2 months that followed, leaving slight hemiparesis and homonymous left upper quadrant anopsia In the following 3 years, no recurrence was seen with aspirin (81 mg/day). FMD in the head and neck usually affects extracranial segments of the carotid and vertebral arteries, while FMD of the basilar artery is extremely rare. To the best of our knowledge, 12 cases with FMD of the basilar artery have been reported; of these, 11 were symptomatic and 5 died. Since FMD of the basilar artery has poor prognosis, attention needs to be paid for FMD in young adults as a differential diagnosis of cerebral infarction in the territory of the basilar artery.

Adult↗
PubMed2006

[Venous infarction associated with carotid-cavernous fistula].

We report an 88-year-old woman who developed a hemorrhagic venous infarction in the left cerebral hemisphere and brainstem, in association with left carotid-cavernous fistula (CCF). Without aura the patient noticed diplopia due to left abducens palsy, and exophthal mos and congestion of the left eye. Brain CT revealed extrusion of the left eye, and dilatation of left superior orbital vein and cerebral cortical veins. She received diagnosis of CCF. Brain CT also revealed a small mass in the left ethmoidal sinus, which was not attached to the CCF. Biopsy of the mass was done under local anesthesia. On the following she had high fever. Her consciousness level deteriorated and she developed right hemiparesis FLAIR images of MRI showed, extensive high signal lesions in the left frontal and temporal cortices, basal ganglia, thalamus, midbrain and pons. These findings were consisted with venous infarction, possibly associated with peri-operative infection and hypovolemia. Intracranial hemorrhage occur in 3% of cases with CCF, but venous infarction was much rarer. The patients with CCF, who show dilatation of cortical veins in CT or MRI, have a higher risk of cerebral hemorrhage or infarction, and should be carefully observed.

Aged, 80 and over↗
PubMed2004

A case of dermato-fasciitis: amyopathic dermatomyositis associated with fasciitis.

Amyopathic dermatomyositis (ADM) is characterized by the typical cutaneous features of dermatomyositis and minor involvement of the skeletal muscles. A 50-year-old woman had fever, reddening and pain in the distal part of all four limbs, and cutaneous findings such as Gottron's papules and periorbital heliotrope. She showed no muscle weakness or atrophy, and her serum creatine kinase was within the normal range. Electromyography showed no myopathic pattern. Magnetic resonance imaging (MRI) recorded abnormal hyperintensity in the fascia and muscle of the tibialis anterior. A biopsy from the tibialis anterior muscle showed fasciitis and mild myopathic changes with focal perivascular infiltration. This patient also presented with interstitial pneumonitis, although evaluation for malignancy was negative. With steroid therapy, her symptoms and MRI abnormality disappeared within 2 months. This case is therefore considered to be a variant of ADM, presenting as dermato-fasciitis.

Anti-Inflammatory Agents↗
PubMed2003

D-cycloserine for the treatment of ataxia in spinocerebellar degeneration.

We studied the effects of D-cycloserine, a partial NMDA receptor allosteric agonist, on ataxia in patients with spinocerebellar degeneration. Fifteen Japanese ataxic patients enrolled in a 14-day single-blind trial of D-cycloserine (daily oral dose of 50 mg) following a 14-day single-blind placebo phase. At the end of the D-cycloserine administration, there was a significant reduction in the posture, gait and total score of the international cooperative ataxia rating scale and in the time for walking and speech tasks. D-Cycloserine was well-tolerated and no adverse effect was observed. D-Cycloserine may have therapeutic efficacy for spinocerebellar ataxia.

Adult↗
PubMed2003

[A case of severe parkinsonism induced by failure of ventriculo-peritoneal shunt for aqueductal stenosis].

A 26-year-old man, who had received a ventriculo-peritoneal shunt for obstructive hydrocephalus after possible encephalitis, complained of disturbance of upward gaze and difficulty in movement seven months after the shunt implantation. One month later, neurological examination revealed upward gaze paresis and rigidity of all four limbs, but the neuroimaging studies revealed no ventricular dilatation. His symptoms deteriorated, and tremor of the extremities appeared. He was admitted to our hospital 10 months after the shunt implantation. He developed akinetic mutism soon after admission. Cerebrospinal fluid protein was elevated (62 mg/dl). At that time, the shunt reservoir was found to be insufficiently filled, and neuroimaging showed dilatation of the lateral and third ventricles with no dilatation of the fourth ventricle. A neuroendoscopic third ventriculostomy with removal of the previous shunt system gradually resolved the parkinsonism within two months, and the patient became capable of walking. The dilatation of the ventricles improved on neuroimaging. The present report suggests that shunt malfunction should be suspected when parkinsonism occurs in patients who have undergone a shunt placement, even though hydrocephalus on neuroimaging is not observed.

Adult↗
PubMed2002

Feasibility and limitations of magnetoencephalographic detection of epileptic discharges: simultaneous recording of magnetic fields and electrocorticography.

Magnetoencephalography (MEG) is considered clinically useful in localizing the epileptogenic focus in partial epilepsy. However, the relationship between the extent of the brain involved in paroxysmal activities and the magnetic field changes at the scalp has not been fully clarified. Furthermore, whether paroxysmal activities generated in deep brain structures such as the hippocampus can be detected magnetically is uncertain. Eight patients with temporal lobe epilepsy and two with extratemporal lobe epilepsy underwent chronic recording from subdural electrodes. Magnetic and electrocorticographic discharges representing epileptic activity were recorded simultaneously. MEG recorded magnetic field changes originating from paroxysmal activity in the superiolateral cerebral cortex when the amplitudes of the electrical paroxysmal activities exceeded 100 microV and extended over more than 3 cm2 of cortical surface. MEG failed to record paroxysmal activity localized to the medial temporal lobe. MEG is often useful in identifying a spike focus in the superiolateral aspects of the cerebral hemisphere, but not discharges arising from the medial temporal lobe. Rapid decay of the magnetic field is likely to be the reason for this limited sensitivity to medial discharges.

Adolescent↗
PubMed2002

[Juvenile-onset multiple brain infarcts localized in the posterior circulation: a case report].

We report a 37-year-old male patient with multiple brain infarcts due to arterial lesions localized in the posterior circulation, who developed a paramedian pontine infarct on the left side. He had been treated as schizophrenia for 20 years. A cranial CT performed one year before showed old small infarcts in the territories of the bilateral thalamo-perforating and left thalamo-geniculate arteries and the right posterior inferior cerebellar artery. The vertebral and basilar arteries were small in diameter on MRI and MR angiography(MRA). Cerebral angiography revealed a narrow smooth basilar artery. In addition, the P2 segments of the bilateral posterior cerebral arteries were markedly narrow with irregular walls. Carotid arteriograms were normal and no atherosclerosis was found. The nature of these arterial lesions remains unknown in this case. Even if MRA shows vertebrobasilar artery hypoplasia, a known congenital risk factor of a posterior circulation infarct, we must rule out a possibility that some arterial pathology is going on.

Adult↗
PubMed2002

[Facioscapulohumeral muscular dystrophy with sinus dysfunction].

We report a 47-year-old man with facioscapulohumeral muscular dystrophy (FSHD) presenting with sinus dysfunction. He became unable to roll over and stand up at the age of 42, but he could still walk. Facial muscle involvement, scapular winging, asymmetrical involvement, funnel chest, and the absence of contractures were typical of FSHD. Electrocardiogram (ECG) and cardiac echogram showed the overload of both right atrium and ventricle. On Holter ECG, transient P wave inversion and P-P interval elongation (maximally 2.4 seconds) repeatedly appeared mainly during sleep. There was no bundle branch block, atrioventricular junctional rhythm, or increase of premature ventricular beats. Vital capacity was decreased (0.62 L, 16% of the predicted value). Arterial blood gas analysis showed hypercapnia and hypoxia which aggravated during sleep (PaCO2 87.3Torr, PaO2 41.5Torr). Sleep apnea was not observed. Intracardiac ECG was not performed and he died 2 weeks later. In FSHD, sinus node dysfunction may become distinct especially in the setting of respiratory failure.

Electrocardiography, Ambulatory↗
PubMedDate not supplied

[A patient with mitochondrial encephalomyopathy presenting gynecomastia with elevation of serum estriol level].

We report a 23-year-old man with mitochondrial encephalomyopathy. At 21 years of age, he noted speech distubance. Since his dysarthria did not improve thereafter, he was admitted to our hospital. On admission, he showed mild gynecomastia. Neurological examination revealed mild decrease in performance IQ in WAIS-R, mild scanning speech, mild left hearing disturbance, mild to moderate muscle weakness in proximal four extremities, mild bilateral limb ataxia, and mild to moderate truncal ataxia. While, no brisk deep tendon reflex, pathological reflex, aberrant muscle tonus, sensory disturbance, retinopathy, myoclonus or autonomic disorder was found. Serum levels of lactate (23.2 mg/dl, normal<18.7) and pyruvate (1.23 mg/dl, normal<0.94) were elevated, and serum lactate levels were markedly elevated (118.1 mg/dl) after 15-minute exercise (15 Watts/minute). CSF levels of lactate (31.2 mg/dl, normal<12.5) and pyruvate (1.48 mg/dl, normal<0.75) were also elevated. Head MRI showed mild cerebral and cerebellar atrophy, but 1H-MRS showed no lactate peak. Moreover, muscle biopsy from left biceps muscle showed lots of ragged-red fibers, and he was thus diagnosed as having mitochondrial encephalomyopathy. However, nt3243 mutation of mitochondria DNA was not present. Next, we confirmed gynecomastia by mammography, and checked serum levels of estrogens. Mildly decreased estradiol (19.9 pg/ml, normal, 20-59), normal estrone (24.0 pg/ml, normal<30.0) and mildly increased estriol (6.03 pg/ml, normal<5.0) were found. While, the serum levels of cortisol, dehydroepiandrosterone-sulfate (DHEA-S), androstenedione, testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were all within normal limits. Since the steroid hormone synthesis system and hypothalamus-pituitary system seem to be normal, 16alpha-hydroxylase that converts estradiol to estriol may be upregulated. While, aromatase (P-450arom) is well known to convert androgens to estrogens. In addition, 16alpha-hydroxylase and P-450arom convert DHEA-S to estriol. Since it is recently reported that P-450arom is considerably expressed in muscle tissues as well as fat tissues and that muscle tissue may be a major organ to produce estrogens in men and postmenopausal women, estriol production may be increased in the present patient's muscle. Although hypogonadism due to hypothalamus-pituitary disorders was sometimes reported, there have been no reports that suggest an increased estrogen production in skeletal muscles in mitochondrial encephalomyopathies. Recently, estrogen has been known to protect muscle fibers from oxidative damages due to exercise. Thus, it is of potential that estrogens increased locally in muscle tissues of the patients with mitochondrial encephalomyopathies protect muscle fibers from oxidative damage due to mitochondrial dysfunction.

Adult↗