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Dive into the research topics where Mitsuharu Yoshiyama is active.

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Featured researches published by Mitsuharu Yoshiyama.


Autonomic Neuroscience: Basic and Clinical | 2001

Questionnaire-based assessment of pelvic organ dysfunction in Parkinson's disease

Ryuji Sakakibara; Hitoshi Shinotoh; Tomoyuki Uchiyama; Mitsufumi Sakuma; Masahide Kashiwado; Mitsuharu Yoshiyama; Takamichi Hattori

Although patients with Parkinsons disease (PD) experience pelvic organ dysfunction of the urinary bladder, bowel and genital organs, an accurate incidence of the dysfunction and its characteristics have yet to be ascertained. We devised a detailed questionnaire on these three pelvic organ functions in PD patients and control subjects, in our search for a hallmark that would distinguish between the two groups. The PD group comprised 115 patients; 52 men and 63 women, age range 35-69 (average 59) years old, average duration of illness 6 years, median Hoehn and Yahr stage 3. All were taking levodopa with/without dopamine agonists. The control group comprised 391 local individuals who were undergoing an annual health survey; 271 men and 120 women, age range 30-69 (average 48) years old. The questionnaire had three parts: bladder (nine questions), bowel (four questions), and sexual (three questions for women, five for men) function. Each question was scored from 0 (none) to 3 (severe) with an additional quality of life (QOL) index scored from 0 (satisfied) to 3 (extremely dissatisfied). The completion rate was 100% for bladder and bowel functions, whereas for sexual function, it was 95% (control) and 88% (PD) for men and 82% (control) and 60% (PD) for women. As compared with the control group, the frequency of dysfunction in the PD group was significantly higher for urinary urgency (women 42%, men 54%), daytime frequency (28%, 16%), nighttime frequency (53%, 63%), urgency incontinence (25%, 28%), retardation (44% of men), prolongation/poor stream (men 70%), straining (women 28%); constipation (63%, 69%), difficulty in expulsion (men 57%), diarrhea (men 21%); decrease in libido (84%, 83%), decrease in sexual intercourse (55%, 88%), decrease in orgasm (men 87%), and in men, decreases in erection (79%) and ejaculation (79%). The QOL index for the PD patients was significantly higher for bladder (27%, 28%) and bowel (46%, 59%) but not for sexual dysfunction, despite the groups high prevalence of sexual dysfunction. In the PD patients, fecal incontinence was associated with urinary incontinence. Stress urinary incontinence and a decrease in libido were more common in women than in men. Bladder and bowel dysfunction, but not sexual dysfunction increased with the Hoehn and Yahr stage. Sexual dysfunction, but neither bladder nor bowel dysfunction, increased with age. Patients taking levodopa and bromocriptine more frequently had bladder (voiding phase) dysfunction than those taking levodopa only. The findings show that bladder, bowel and sexual dysfunction are all prominent in patients with PD. Amelioration of pelvic organ dysfunction, particularly bowel dysfunction which most affects the quality of life, therefore should be a primary target in the treatment of patients with PD.


Journal of the Neurological Sciences | 2001

SPECT imaging of the dopamine transporter with [123I]-β-CIT reveals marked decline of nigrostriatal dopaminergic function in Parkinson's disease with urinary dysfunction

Ryuji Sakakibara; Hitoshi Shinotoh; Tomoyuki Uchiyama; Mitsuharu Yoshiyama; Takamichi Hattori; Tomonori Yamanishi

We studied a correlation of urinary dysfunction with nigrostriatal dopaminergic deficit in Parkinsons disease (PD) by single-photon emission computed tomography (SPECT) imaging of dopamine transporter with [123I]-2beta-carbomethoxy-3beta-(4-iodophenyl)tropane (beta-CIT). Eleven patients were enrolled in the study, including four men and seven women, with a mean age of 64 years. Seven patients had urinary symptoms 1-5 years after the onset of motor disorder, which included nighttime frequency in six, urinary retardation in four, daytime frequency in one and urge urinary incontinence in one. Using a SPECT camera, the ratio specific to nondisplaceable [123I]-beta-CIT uptake, designated as striatal V3 was obtained in the caudate, anterior and posterior putamen 24 h after the tracer injection. The striatal V3 was compared in patients with and without urinary dysfunction, and between men and women, using unpaired Students t-test. Correlation of motor dysfunction and duration of illness with urinary dysfunction, was also analyzed. In the patients, there was a reduction of [123I]-beta-CIT binding in the striatum on both sides, particularly in the putamen contralateral to the affected body side. The striatal V3 of the caudate (p<0.01, Rt; p<0.05, Lt), anterior putamen (p<0.05, Rt) and posterior putamen (p<0.05, Rt) in patients with urinary dysfunction was significantly reduced than those without urinary dysfunction. No sex difference was seen in reduction of [123I]-beta-CIT binding. Urinary dysfunction in PD was more common in patients with higher Unified Parkinsons Disease Rating Scale (UPDRS) score, higher Hoehn-Yahr grade, but not in those with longer duration of disease, although there was no statistical significance. It is likely that our results reflect the association of urinary dysfunction and degeneration of the nigrostriatal dopaminergic cells in PD.


Clinical Autonomic Research | 2003

The effect of intranasal desmopressin on nocturnal waking in urination in multiple system atrophy patients with nocturnal polyuria

Ryuji Sakakibara; Shinji Matsuda; Tomoyuki Uchiyama; Mitsuharu Yoshiyama; Tomonori Yamanishi; Takamichi Hattori

Abstract. Nocturnal waking in urination (nocturia) is a common feature in patients with multiple system atrophy (MSA). Degeneration of arginine vasopressin (AVP) neurons in the suprachiasmatic nucleus in this disorder may lead to nocturnal polyuria, which has been treated with intramuscular desmopressin. We also prescribed 5 μg of intranasal desmopressin once a night in 3 MSA patients, who had nocturnal polyuria with abnormal circadian rhythm of the plasma AVP. During the treatment, all patients showed an improvement in their nocturia without serious adverse effects.


Autonomic Neuroscience: Basic and Clinical | 2002

Micturition-related electrophysiological properties in the substantia nigra pars compacta and the ventral tegmental area in cats

Ryuji Sakakibara; Ken Nakazawa; Tomoyuki Uchiyama; Mitsuharu Yoshiyama; Tomonori Yamanishi; Takamichi Hattori

Parkinsons disease patients are known to have not only motor but also urinary autonomic disorders, suggesting central dopaminergic pathways being involved in the micturition function. However, there is little evidence that the substantia nigra pars compacta (SNC) and the ventral tegmental area (VTA), the major dopamine-containing nuclei in the midbrain, should participate in regulating micturition. We investigated micturition-related electrophysiological properties in the SNC and VTA. In 20 male cats under ketamine anaesthesia, in which spontaneous isovolumetric micturition reflex was generated, we performed electrical stimulation and extracellular single-unit recording in the SNC and the VTA, and correlation analysis of the neuronal firings and antidromic stimulation between the SNC/VTA and the pontine storage centre (PSC). Electrical stimulations in the SNC elicited termination of the micturition reflex, whereas those in the VTA elicited both termination and facilitation of the reflex. Forty-nine neurons in the SNC/VTA showed firing in response to the bladder storage/micturition cycles. The major neurons were tonic storage (55%) and phasic storage neurons (22%), which were found diffusely in th e SNC/VTA. The rest were tonic micturition (16%) and phasic micturition neurons (6%), which were concentrated in the caudal part (A2-4 in the Horsley-Clarke coordinates). These neuronal types were further subclassified into augmenting, constant, binary and decrementing neurons according to their temporal discharge rate change. The decrementing neurons were concentrated in the caudal part (A2-4), whereas the augmenting neurons in the rostral part (A4-6). Some of the recorded neurons had preceding firing pattern, which was more frequently found in the tonic type than in the phasic-type neurons. Twenty-four of the neuronal firings in the SNC/VTA were recorded simultaneously with those in the PSC. However, there was no apparent time-correlation between both sets of neuronal firings. In 15 of the simultaneous recording sites, electrical stimulation was applied to one site to see if antidromic response might be evoked in another site. However, there was no orthodromic or antidromic response in either SNC/VTA or PSC. In conclusion, the present study indicates that neurons in the SNC and the VTA are involved in supra-pontine control of micturition, particularly of urinary storage phase. It is also likely that the major role of the SNC is inhibition of the micturiton reflex, whereas that of the VTA is both facilitation and inhibition of the micturition reflex.


Neuroscience | 2003

Effects of subthalamic nucleus stimulation on the micturation reflex in cats

Ryuji Sakakibara; Ken Nakazawa; Tomoyuki Uchiyama; Mitsuharu Yoshiyama; Tomonori Yamanishi; Takamichi Hattori

High frequency stimulation (HFS) of the subthalamic nucleus (STN) has been performed to reverse motor dysfunction in severe parkinsonian patients. Recent studies suggested that neural circuitry in the basal ganglia might regulate micturition function as well. In 15 adult male cats under ketamine anesthesia, in which spontaneous isovolumetric micturition reflex had been generated, we performed electrical stimulation and extracellular single unit recording in the STN. Electrical stimulation applied in the STN elicited inhibition of the micturition reflex. None of the responses was facilitatory. Effective amplitude of the electrical stimulation for evoking inhibitory responses was less than 50 microA, which gradually increased and exceeded 250 microA as the location of the stimulation exceeded an area of the STN. Effective frequency of the electrical stimulation with given stimulus intensity was 50 Hz and higher. Total 10 neurons were recorded in the STN that were related to urinary storage/micturition cycles. All neurons were tonically active throughout storage/micturition cycles with storage phase predominance, with almost constant firing activities during the storage phase. In conclusion, our results showed that HFS-STN inhibited the micturition reflex and there were micturition-related neuronal firings in the STN in cats, suggesting the STN may be involved in neural control of micturition. The results also provide an implication that clinical HFS-STN may alter urinary function in parkinsonian patients.


Journal of the Neurological Sciences | 2002

Successful immune treatment for non-paraneoplastic limbic encephalitis

Masahiro Mori; Satoshi Kuwabara; Mitsuharu Yoshiyama; Toshihide Kanesaka; Tsuyoshi Ogata; Takamichi Hattori

A 21-year-old woman subacutely developed memory loss subsequent to gastroenteritis. Brain MRI with gadolinium enhancement showed symmetric involvement of the amygdala. The CSF was acellular with increased protein level. There was no evidence suggestive of neoplasm or viral infection. Combined treatment with plasmapheresis and immunoglobulin improved her clinical symptoms and lessened abnormalities manifested in the MRI. This case suggests the presence of immune-mediated limbic encephalitis without association with neoplasms or infections.


Autonomic Neuroscience: Basic and Clinical | 2002

Firing patterns of micturition-related neurons in the pontine storage centre in cats.

Ryuji Sakakibara; Ken Nakazawa; Keisuke Shiba; Yoshio Nakajima; Tomoyuki Uchiyama; Mitsuharu Yoshiyama; Tomonori Yamanishi; Takamichi Hattori

The pontine storage centre (PSC) and the pontine micturition centre (PMC) are known to be critical for urinary filling and emptying, respectively. In the present study, firing patterns of 45 neurons in the PSC area where electrical stimulation induced inhibition of the micturition reflex were analyzed in 20 male decerebrated and paralyzed cats. The electrically determined PSC area was widespread in the dorsolateral pontine reticular formation (P0-P4), ventrolateral to the PMC. Four major types of neurons were detected according to urinary storage/micturition cycles: tonic storage neurons (38%), phasic storage neurons (40%), tonic micturition neurons (9%) and phasic micturition neurons (13%). These four types of neurons were intermingled in the PSC. However, the tonic and phasic micturition neurons tended to be located within a limited area (P2-P3). These neurons were further classified into augmenting, constant and decrementing firing patterns. Some increased their firing prior to the storage/micturition phase initiation. Such preceding pattern was more frequently found in the tonic neurons than in the phasic neurons. In conclusion, the PSC neurons with diverse heterogeneous discharge patterns suggest that these neurons may organize a complex neuronal circuitry, which is critical in the neural control of the urinary continence.


Clinical Autonomic Research | 2003

Amezinium metilsulfate, a sympathomimetic agent, may increase the risk of urinary retention in multiple system atrophy.

Ryuji Sakakibara; Tomoyuki Uchiyama; Masato Asahina; Mitsuharu Yoshiyama; Tomonori Yamanishi; Takamichi Hattori

Abstract. In 5 patients with multiple system atrophy, administration of 15 mg/day of amezinium metilsulfate, an adrenergic agent, during 6 months for the treatment of postural hypotension exacerbated post-micturition residuals as compared to that before treatment (178 ml versus 113 ml for a change of 37 %, p < 0.05). Amezinium metilsulfate most probably stimulates both α1B-receptors in the vascular wall and α1A/D-receptors in the proximal urethra.


Neurourology and Urodynamics | 2005

Preliminary Communication: Urodynamic Assessment of Donepezil Hydrochloride in Patients With Alzheimer's Disease

Ryuji Sakakibara; Tomoyuki Uchiyama; Mitsuharu Yoshiyama; T. Yamanishi; Takamichi Hattori


Neurourology and Urodynamics | 2003

Urinary Dysfunction in Patients With Systemic Lupus Erythematosis

Ryuji Sakakibara; Tomoyuki Uchiyama; Mitsuharu Yoshiyama; Tomonori Yamanishi; Takamichi Hattori

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Hitoshi Shinotoh

National Institute of Radiological Sciences

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