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Dive into the research topics where Atsuya Suzuki is active.

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Featured researches published by Atsuya Suzuki.


Journal of Neurology, Neurosurgery, and Psychiatry | 2000

Urinary dysfunction and orthostatic hypotension in multiple system atrophy: which is the more common and earlier manifestation?

Ryuji Sakakibara; Takamichi Hattori; Tomoyuki Uchiyama; K. Kita; Masato Asahina; Atsuya Suzuki; Tomonori Yamanishi

OBJECTIVES Urinary dysfunction and orthostatic hypotension are the prominent autonomic features in multiple system atrophy (MSA). A detailed questionnaire was given and autonomic function tests were performed in 121 patients with MSA concerning both urinary and cardiovascular systems. METHODS Replies to the questionnaire on autonomic symptoms were obtained from 121 patients including three clinical variants; olivopontocerebellar atrophy (OPCA) type in 48, striatonigral degeneration (SND) type in 17, and Shy-Drager type in 56. Urodynamic studies comprised measurement of postmicturition residuals, EMG cystometry, and bethanechol injection. Cardiovascular tests included head up tilt test, measurement of supine plasma noradrenaline (norepinephrine,NA), measurement of R-R variability (CV R-R), and intravenous infusions of NA and isoproterenol. RESULTS Urinary symptoms (96%) were found to be more common than orthostatic symptoms (43%) (p<0.01) in patients with MSA, particularly with OPCA (p<0.01) and SND (p<0.01) types. In 53 patients with both urinary and orthostatic symptoms, patients who had urinary symptoms first (48%) were more common than those who had orthostatic symptoms first (29%), and there were patients who developed both symptoms simultaneously (23%). Post-micturition residuals were noted in 74% of the patients. EMG cystometry showed detrusor hyperreflexia in 56%, low compliance in 31%, atonic curve in 5%, detrusor-sphincter dyssynergia in 45%, and neurogenic sphincter EMG in 74%. The cystometric curve tended to change from hyperreflexia to low compliance, then atonic curve in repeated tests. Bethanechol injection showed denervation supersensitivity of the bladder in 19%. Cardiovascular tests showed orthostatic hypotension below –30 mm Hg in 41%, low CV R-R below 1.5 in 57%, supine plasma NA below 100 pg/ml in 28%, and denervation supersensitivity of the vessels (α in 73%; β2 in 60%) and of the heart (β1 in 62%). CONCLUSION It is likely that urinary dysfunction is more common and often an earlier manifestation than orthostatic hypotension in patients with MSA, although subclinical cardiovascular abnormalities appear in the early stage of the disease. The responsible sites seem to be central and peripheral for both dysfunctions.


Acta Neurologica Scandinavica | 2002

Autonomic function in demyelinating and axonal subtypes of Guillain–Barré syndrome

M. Asahina; Satoshi Kuwabara; Atsuya Suzuki; Takamichi Hattori

Objectives– To investigate whether or not the pattern and extent of autonomic involvement differ between the two subtypes of Guillain–Barré syndrome (GBS), namely acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). Methods – Head‐up tilt test, R–R interval variation, plasma noradrenaline concentration, skin vasomotor reflex (SVR) and sympathetic sweat response (SSwR) were used to estimate autonomic function in seven AIDP and eight AMAN patients. Results – Heart rate and plasma noradrenaline concentration were significantly high in the AIDP group but not in the AMAN group. Skin vasomotor reflexes were generally preserved and SSwRs were impaired in patients with severe neurological deficits for both AIDP and AMAN groups. Conclusion – The patterns of autonomic involvement are qualitatively different between AIDP and AMAN. Acute inflammatory demyelinating polyneuropathy is characterized by cardio‐sympathetic hyperactivity, excessive or reduced sudomotor function and preserved skin vasomotor function, while AMAN is not necessarily generally associated with marked autonomic dysfunction except for the sudomotor hypofunction seen in patients with severe neurological deficits.


International Journal of Psychophysiology | 2003

Emotional sweating response in a patient with bilateral amygdala damage

Masato Asahina; Atsuya Suzuki; Masahiro Mori; Toshihide Kanesaka; Takamichi Hattori

Sweat output on the palm or sole is distinct from thermoregulatory sweating and has been designated emotional sweating. The amygdala has been implicated in this phenomenon, but the role it plays remains unclear. We had the chance to evaluate emotional sweating in a 21-year-old female with bilateral restricted amygdala lesions caused by idiopathic subacute limbic encephalitis. At the peak of the illness, sweat responses in the palm were not evoked in this patient in conjunction with any sympathetic activation procedures, including deep inspiration, mental arithmetic, isotonic exercise, and tactile stimulation. After neurological improvement associated with diminution of amygdala lesions on the magnetic resonance imaging, normal sweat responses were incited. This indicates that the amygdala does play an important role in emotional sweating.


Clinical Autonomic Research | 2003

Cutaneous sympathetic function in patients with multiple system atrophy

Masato Asahina; Yuriko Kikkawa; Atsuya Suzuki; Takamichi Hattori

Abstract. Some procedures increase the sweat output (SSwR; sympathetic sweat response) and reduce the cutaneous blood flow (SVR; skin vasomotor reflex) in the hand. We evaluated SSwRs and SVRs to deep inspiration, mental arithmetic, exercise, and tactile stimulation in 40 MSA patients and 15 healthy controls. We also conducted head-up tilt tests and R-R interval variation tests (CVR-R).SSwRs were present in all controls, but absent in 19 (47.5 %) of the MSA patients. The mean SSwR amplitudes in the MSA group were significantly lower than those in the control group. SVRs were evoked in all subjects except 3 MSA patients. There were no marked differences in SVR amplitudes between the two groups. Orthostatic hypotension and low CVR-R values were seen in 18 (45 %) and 13 (32.5 %) of the MSA patients, respectively. SSwR amplitudes correlated significantly with postural fall in blood pressure and CVR-R values in the MSA group.SSwRs were absent in about half of the MSA patients, and the SSwR results correlated with those of the cardiovascular autonomic tests. The SVRs were not severely disturbed in the MSA patients. We considered SSwR a useful index for the detection of autonomic dysfunction in MSA.


Parkinsonism & Related Disorders | 2003

Cutaneous sympathetic function and cardiovascular function in patients with progressive supranuclear palsy and Parkinson's disease

Yuriko Kikkawa; Masato Asahina; Atsuya Suzuki; Takamichi Hattori

Some procedures, such as deep inspiration, increase sweat output (SSwR; sympathetic sweat response) and reduce cutaneous blood flow (SVR; skin vasomotor reflex) on the palm. We investigated SSwR, SVR, and cardiovascular function in 12 patients with progressive supranuclear palsy (PSP), 13 patients with Parkinsons disease (PD), and 9 healthy subjects. In the PSP patients, SSwR was severely diminished, whereas SVR was maintained and cardiovascular function was well preserved. In the PD patients, SSwR was relatively preserved, SVR was maintained, and some patients showed cardiovascular hypofunction. A combination of skin sympathetic and cardiovascular tests may be useful for distinguishing between PD and PSP.


Clinical Autonomic Research | 2005

Impaired circadian rhythm of gastric myoelectrical activity in patients with multiple system atrophy

Atsuya Suzuki; Masato Asahina; C. Ishikawa; K. M. Asahina; K. Honma; Toshio Fukutake; Takamichi Hattori

In order to evaluate gastric motility and its circadian rhythm in patients with multiple system atrophy (MSA) and healthy control subjects, we measured gastric myoelectrical activity (GMA) for 24 hours using a cutaneous electrogastrogram (EGG) recorder in 14 MSA patients and 9 age-matched controls.We analyzed six 10-minute segments of EGG before and after each meal and two 20-minute EGG segments during sleep; three parameters were used for the analysis: dominant frequency (DF), instability coefficient of dominant frequency (ICDF), and dominant power (DP). DF increased during daytime and decreased during sleep in the control, while this circadian variation was blunted in the patients with MSA. The average DF of the eight segments in the MSA patients did not differ from that of the control. Both MSA patients and control subjects did not show the circadian variation of ICDF and DP. The average ICDF of the eight segments in the patients with MSA was significantly decreased when compared with that of the control (p<0.01). No differences were observed in DP between the two groups. This study indicates that the healthy subjects appear to have a circadian rhythm of DF, and the patients with MSA appear to have impaired circadian rhythm of DF and decreased ICDF possibly due to the degeneration of the central autonomic neurons.


Movement Disorders | 2009

Gastric myoelectrical differences between Parkinson's disease and multiple system atrophy.

Yumi Sakakibara; Masato Asahina; Atsuya Suzuki; Takamichi Hattori

The electrogastrogram (EGG) was recorded for 24 hours in 17 Parkinsons disease (PD) patients, 17 multiple system atrophy (MSA) patients, and 8 healthy control subjects to elucidate the differences in the EGG findings between the two diseases. Eight EGG segments (3 preprandial, 3 postprandial, and 2 sleep segments) were selected from the total recording for spectral analysis, from which we obtained the dominant frequency (DF), instability coefficient of DF (ICDF), and low (LFR%), normal (NFR%), and high (HFR%) range power percentages of the total power. PD patients showed irregular slow waves, high HFR%, and high ICDF, whereas MSA patients showed regular slow waves and low ICDF. Although DF and NFR% increased after meal in controls, postprandial increases in DF and NFR% were less significant in both patient groups compared to the controls. The PD patients presented gastric dysrhythmias indicating gastric pacemaker disturbances. The MSA patients showed regular slow waves with low variability of the slow wave rhythm (low ICDF), which might have resulted from the involvement of gastric autonomic nerve function.


Journal of Neurology, Neurosurgery, and Psychiatry | 2004

Micturition disturbance in acute idiopathic autonomic neuropathy

Ryuji Sakakibara; Tomoyuki Uchiyama; M. Asahina; Atsuya Suzuki; Tomonori Yamanishi; Takamichi Hattori

Objective: To define the nature of micturition disturbance in patients with acute idiopathic autonomic neuropathy (AIAN). Methods: Micturitional symptoms were observed during hospital admissions and the in outpatient clinics in six patients with clinically definite AIAN (typical form in four, cholinergic variant in one, autonomic-sensory variant in one). Urodynamic studies included medium-fill water cystometry, external sphincter electromyography, and a bethanechol test. Results: Four patients had urinary retention and two had voiding difficulty as the initial presentation. Patients with retention became able to urinate within a week (two to seven days). The major symptoms at the time of urodynamic studies (three weeks to four months after disease onset in most cases) were voiding difficulty and nocturnal frequency. None had urinary incontinence. Complete recovery from the micturition disturbance took from three months to >18 years. The recovery period was shorter in a patient with cholinergic variant, and it was longer in two patients who had a longer duration of initial urinary retention. Micturition disturbance tended to improve earlier than orthostatic hypotension. The major urodynamic abnormalities were detrusor areflexia on voiding (5), denervation supersensitivity to bethanechol (3); low compliance detrusor (1); and impaired bladder sensation (2). None had neurogenic motor unit potentials of the external sphincter muscles. Conclusions: In patients with AIAN, urinary retention and voiding difficulty are common initial presentations. The underlying mechanisms seem to be pre- and postganglionic cholinergic dysfunction with preservation of somatic sphincter function. The bladder problems tend to improve earlier than orthostatic hypotension.


Internal Medicine | 2008

Cerebral Oxygenation Monitoring for Detecting Critical Cerebral Hypoperfusion in Patients with Multiple System Atrophy during the Head-up Tilt Test

Koji Suzuki; Masato Asahina; Atsuya Suzuki; Takamichi Hattori


Neurourology and Urodynamics | 2005

Bilateral lesion in the lateral columns and complete urinary retention: Association with the spinal cord descending pathway for micturition

Akiyuki Hiraga; Ryuji Sakakibara; Masahiro Mori; Atsuya Suzuki; Takamichi Hattori

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