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Biomedical subjects

F Moriwaka

Publications and source records attributed to F Moriwaka.

At least 19 recordsLinked to original sources

Prevalence of Parkinson's disease in Hokkaido, the northernmost island of Japan.

The prevalence of Parkinson's disease (PD) was investigated in Hokkaido, the northernmost island of Japan. A pilot case-finding study was carried out to estimate the prevalence in the entire island of Hokkaido (population = 5,643,647) initially, then we surveyed the prevalence at one of the smaller cities, Iwamizawa City (population = 80,417). We ascertained 5,342 cases with PD in Hokkaido and 77 cases in Iwamizawa City, estimating the crude prevalence of 94.7/100,000 in Hokkaido (June 30, 1993) and 95.8/100,000 in Iwamizawa City (April 1, 1994), respectively. We calculated that the crude prevalence rate of PD in Japan in currently close to 100/100,000, but the age-adjusted prevalence is still low, compared with those in Europe and North America.

Adult

[A case of acute disseminated encephalomyelitis (ADEM) associated with demyelinating peripheral neuropathy].

A 41-year-old man had common cold on April 10, 1991. Five days after this illness he developed fever, dysarthria, visual field impairment, gait disturbance and consciousness disturbance followed. On admission in another hospital, cerebrospinal fluid showed 341/mm3 cells (303 mononuclear cells, 33 polynuclear cells, 5 red cells), protein of 238 mg/dl, and sugar of 59 mg/dl. One month later, the neurological examinations revealed flaccid paraparesis, decreased deep tendon reflexes in the lower extremities, bilateral positive Babinski and Chaddock reflexes, positive Beevor sign, stocking type superficial sensory disturbance, diminished vibration sense in the lower extremities and neurogenic bladder. Eight months later, he improved to be able to walk by himself, but decreased Achilles tendon reflexes, bilateral positive Babinski and Chaddock reflexes and paresthesia over both feet were noted neurologically. Nerve conduction study revealed reduced conduction velocities at tibialis anterior nerves, sural nerves and no response on both deep peroneal nerves. A 1 micron thick epon section of a biopsied sural nerve with toluidine blue stain showed a decreased number of myelinated fibers (6394/mm2) with many thinly myelinated fibers and Renaut bodies. There was no edema nor cell infiltration. Electronmicroscopical findings of their ultrathin sections showed many collagen pockets, denervated Schwann cell clustering and a few onion bulb formations. Teased fiber preparations suggested segmental demyelination and remyelination in many fibers. This case could be regarded as a case of ADEM associated with demyelinating peripheral neuropathy, and the possibility of the simultaneous demyelinating process in the central and peripheral nervous system was discussed.

Adult

Visual function in patients with optic neuritis associated with acute transverse myelopathy in multiple sclerosis.

The authors reviewed the records of 20 patients with optic neuritis, all of whom were diagnosed as having clinically definite multiple sclerosis (MS). They were classified into two subgroups: Group A, consisting of 9 patients who had shown acute transverse myelopathy (ATM); and Group B, 11 patients without ATM. Four patients (44%) in Group A had complete visual loss, but none in Group B. Six patients (67%) in Group A had less than 0.1 visual acuity in the affected eye, but only 2 patients (18%) in Group B. Four patients in Group A showed evidence of anticardiolipin antibodies. While both groups were diagnosed as having clinically definite MS, there were differences between them in the clinical features. We assume that the patients with ATM may constitute a different subgroup among MS patients.

Acute Disease

[Epidemiology of syringomyelia in Japan--the nationwide survey].

The nationwide epidemiological survey of syringomyelia was carried out in Japan by sending inquiries to neurologists, child neurologists, neurosurgeons and orthopedic surgeons for the period of 1991 and 1992. A total of 1,243 cases of syringomyelia were ascertained. Among them, 622 were men and 619 women, and the average age of onset was 28 years old. The classification by Barnett et al was used, presenting syringomyelia with Chiari malformation in 684 cases (51.2%), dysraphism in 47 (3.7%), post traumatic syringomyelia in 139 (11%), post-spinal arachnoiditis in 76 (6%), spinal cord tumor in 132 (10.5%) and others in 204. Its predominant clinical course was slowly progressive, but 202 cases (17.9%) showed rather stable course including spontaneous resolution in 29 cases. The main initial symptoms were numbness in 522 cases (42%), motor disturbance in 504 (40.5%), and pain in 296 (23.8%). Neurologic signs noted in the abnormality of deep tendon reflexes in 836 cases (67.3%), motor disturbance in 763 (60.4%) and positive pathological reflexes in 383 (30.1%). Sensory disturbance was found in 942 cases (75.8%) and the dissociated type were 559 out of them (59.3%). It is noteworthy that 982 out of 1,243 were documented by MRI and surgical operations such as foramen magnum decompression, syringo-subarachnoid shunt and others were performed in 829 cases. Syringobulbia was confirmed on MRI in 101 cases of syringomyelia in which spinal cord tumors were most frequently associated.

Adolescent

MR appearance of subacute combined degeneration of the spinal cord.

Subacute combined degeneration (SCD) of the spinal cord is well known to produce degenerative lesions in the spinal cord histopathologically, but a few reports on the neuroradiological findings have so far been reported. We presented the MRI findings of the spinal cord in a case of SCD. The localization of the radiologically proven lesions was similar to that of the previous pathological reports.

Aged

Residual neurobehavioural effects associated with chronic exposure to mercury vapour.

To find the residual effects of long term exposure to mercury vapour, neurobehavioural tests were given to ex-mercury miners about 18 years after the end of mercury exposure. Seventy six male ex-mercury miners who had been exposed to high concentrations of mercury vapour (over 1.0 mg/m3) and with a history of mercury intoxication were compared with controls matched for age (within 3 years), sex, and education. Although the extent of the workers' symptoms caused by mercury poisoning, termed erethismus merculialis, decreased considerably after the end of exposure, matched paired comparison showed that performances of motor coordination, simple reaction time, and short term memory had deteriorated significantly in the exposed group. Multiple linear regression analysis of exposure variables with neurological examination measures showed positive correlations between poorer neurological performance and variables related to mercury exposure. Thus the duration of exposure correlated with poorer performance of hand-eye coordination, tapping, and a colour card reading test. Job categories classified by exposure to mercury also had a significant negative correlation with these performances. The period of years after the end of exposure had a significant correlation with better performance of reaction time and digit span. On the other hand, the history of intoxication itself had no significant correlation with any of the current neurobehavioural performances. These results suggest that there are slight but persistent effects on neurobehavioural function, especially on motor coordination, among mercury miners even more than 10 years after the end of exposure.

Aged

Clinico-radiological findings of neuro-Behçet's syndrome.

We examined 21 cases of Neuro-Behçet's syndrome in detail, and present here their clinicoradiological characteristics. Clinically, signs of pyramidal tract and meningeal irritation were frequently observed. In contrast to previous reports, our study demonstrated a near equal frequency in the occurrence of focal cerebral lesions and that of focal brain stem lesions. Notably, our results showed that the atrophy of both the cerebrum and the brain stem was often observed, indicating the presence of continuous disease activity in the central nervous system (CNS). In accordance with the high frequency of meningeal irritation signs, all of our cases exhibited pleocytosis in the cerebrospinal fluid (CSF). These results indicated the possibility that chemical mediators secreted from infiltrating cells in the CSF may somehow inflict damage to the CNS in Neuro-Behçet's syndrome.

Adult

Sequential magnetic resonance features of encephalopathy induced by systemic mastocytosis.

A 37-year-old man developed encephalopathy with prominent eosinophilia. Magnetic resonance imaging (MRI) revealed multiple T2-weighted high signal intensity lesions with dimeglumine gadopentetate (Gd-DTPA) enhancement on T1-weighted images, which were distributed in the cerebral cortex, thalamus, deep white matter and cerebellum. He was diagnosed as having systemic mastocytosis on the basis of proliferating mast cells in the bone marrow and peripheral eosinophilia. Following steroid administration, there was a rapid improvement of his symptoms and laboratory data. To our knowledge, this was the first reported case of systemic mastocytosis provoking encephalopathy with serial MRI findings.

Adult

Temporal alterations of immunohistochemical findings in polymyositis.

To investigate the pathological mechanisms of polymyositis, we performed immunohistochemical analyses with biopsied muscles. Comparative studies using specimens obtained from the same patient enabled us to analyze the pathological alterations at different sequential clinical phases without taking into account each immunogenetic difference. Expression of MHC (major histocompatibility complex) antigens, especially ectopic MHC-class-II antigens, in muscle fibers and infiltrating T-cells were shown to increase concomitantly with the clinically observed exacerbation. Moreover, other observations seem to support the possibilities that 1) administration of steroids lowers the number of invading CD8-positive cells, 2) induction of MHC-class-I antigens in muscle fibers precedes the inflammatory cell infiltration and that 3) remaining MHC-class-I antigens in muscle fibers may explain the recurrence of myositis often observed in the follow up period.

Adrenal Cortex Hormones

[Visual function in patients with optic neuritis associated with acute transverse myelopathy in multiple sclerosis].

We reviewed the records of 20 patients with optic neuritis who were diagnosed to have clinically definite multiple sclerosis (MS). We classified them into 2 subgroups: group A, consisting of 9 patients who had acute transverse myelopathy (ATM); and group B, 11 patients without ATM. 4 patients (44%) in group A had complete visual loss, but none in group B. 6 patients (67%) in group A had less than 0.1 visual acuity in the affected eye, but only 2 patients (18%) in group B. 4 patients in group A had evidence of anticardiolipin antibodies. While both groups were diagnosed as having clinically definite MS, there were differences in the clinical features between them. We assume that the patients with ATM constitute a different subgroup among MS patients.

Acute Disease

[A case of multiple sclerosis associated with granulomatous panuveitis].

A case of multiple sclerosis (MS) associated with granulomatous panuveitis was reported. A 45-year-old woman developed diplopia in 1972, at age 24, optic neuritis in 1974 and acute transverse myelopathy in 1981. Subsequently, while being under our care with the clinical diagnosis of MS, right abducens palsy in 1989, deterioration of paraparesis with remission in 1991, and weakness of left arm in 1992 occurred. CSF study revealed high IgG index and brain MRI showed multiple abnormal intensity areas in the deep white matter and periventricular areas bilaterally. On the beginning in March, 1993, she noticed left hazy vision and the ophthalmological examinations revealed marked mutton-fat like keratic precipitates, posterior synechiae, cells and flare in anterior chamber, retinal phlebitis and snow ball vitreous opacity. Granulomatous panuveitis was diagnosed and treated by topical steroid with improvement within two months. During this episode, no neurological deterioration was seen. Granulomatous uveitis in MS was rarely documented in the literatures, but this seems to be more common in women, mildly symptomatic or asymptomatic and responds well to topical steroid treatment.

Female

Identification of androgen receptor in the rat spinal motoneurons. Immunohistochemical and immunoblotting analyses with monoclonal antibody.

Androgens play an important role in motoneuron growth, development and regeneration. We proved the existence of androgen receptor (AR) in the motoneurons of the rat spinal cord by the immunohistochemical stain and Western blotting. The possibility that AR protein in spinal cord is expressed in tissue-specific form is proposed, being different from other androgen-dependent tissues. AR abnormality in X-linked spinal and bulbar muscular atrophy (SBMA) among a variety of motor neuron diseases were reported recently. Our study may give some clue to the AR abnormality leading to the degeneration of motoneurons.

Animals

Subjective symptoms and neurobehavioral performances of ex-mercury miners at an average of 18 years after the cessation of chronic exposure to mercury vapor. Mercury Workers Study Group.

In order to determine if there are any residual effects of long-term exposure to mercury vapor, neurobehavioral tests were given to ex-mercury miners about 18 years after the cessation of mercury exposure. Seventy-six male ex-mercury miners who had been exposed to relatively high concentrations of mercury vapor (over 1.0 mg/m3) and with a past history of mercury intoxication were compared to age (+/- 3 years)-, sex-, and years of education-matched controls. Although the extent of the workers' symptoms caused by mercury poisoning, termed erethismus merculialis, markedly decreased after the cessation of exposure, the prevalence of neurological symptoms (such as hand tremors, headaches, and slurred speech) and symptoms of senility (such as low-back pain, loss of sexual desire) in the ex-miners was significantly higher than those in the controls. Matched-pair analysis showed that performances of motor coordination, Simple reaction time, and Short-term memory in the ex-miners were significantly deteriorated compared to those of controls. There are slight but persistent effects on neurobehavioral function, especially on motor coordination function, among mercury miners more than 10 years after the cessation of exposure.

Aged

Motor neuron disease and past poliomyelitis. Geographic study in Hokkaido, the northern-most island of Japan. ALS Study Group.

We carried out a survey on the cases of motor neuron disease (MND) occurring in Hokkaido between 1980 and 1989 in order to establish whether there is a relationship between MND and poliomyelitis. Hokkaido, the northern-most island of Japan, was one of the most affected areas during the poliomyelitis epidemic of the late 1940s to 1950s. We ascertained 389 cases of MND for these 10 years and 2,171 cases of paralytic poliomyelitis for the period 1949-1958, and analysed their geographic distributions. No significant correlation was found between MND and poliomyelitis in their geographic distributions.

Adult

Mercury and selenium contents in amyotrophic lateral sclerosis in Hokkaido, the northernmost island of Japan.

We evaluated the pathogenicity of mercury (Hg) and selenium (Se) which are supposed to be one of the risk factors in the development of amyotrophic lateral sclerosis (ALS). Hg and Se contents were measured in plasma, blood cells, scalp hair samples of 21 sporadic ALS patients and 36 controls, who included 19 patients with other neurological diseases, in Hokkaido, the northernmost island of Japan. Hg and Se levels in plasma and blood cells of ALS patients were significantly lower in advanced staged ALS patients than controls. Low Hg and Se contents in ALS, being correlated with their disabilities and nutritional conditions, would rather reflect the disease contracted states than the pathogenic roles in ALS.

Adult

Myoclonus and seizures in a patient with parkinsonism: induction by levodopa and its confirmation on SEPs.

A 68-year-old woman with parkinsonism showed cortical myoclonus and seizures under antiparkinsonian medication. Myoclonus was induced and enhanced by L-dopa, developing into generalized seizures. EEG was abnormal and somatosensory-evoked potentials (SEPs) showed giant SEPs, transcortical reflex (C reflex) and jerk locked potentials. Myoclonus and seizures disappeared after discontinuation of L-dopa and the introduction of valproate sodium (VPA). We described the occurrence of L-dopa-induced myoclonus and seizures in a case of parkinsonism with its SEPs findings.

Aged