H Yamashita

Hiroshima University, Hiroshima-shi, Hiroshima-ken, Japan

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Publications (9)31.19 Total impact

  • Y Okamoto · N Shirao · K Ueda · M Sekida · H Yamashita · S Yamawaki
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    ABSTRACT: To clarify the mechanism of adaptation to stress in the brain, we performed neuroimaging studies by functional magnetic resonance imaging and magnetoencephalography. First, to investigate which areas of the brain play an important role in the perception of stressful events, we performed fMRI for recognition of unpleasant words concerning interpersonal relationships. Secondly, we evaluated the effect of various stresses on the sensory gating system by MEG to show whether stress could affect the brain mechanism. Finally, we studied the neural activity associated with the expectancy of emotional stimuli using fMRI and MEG, because of the importance of expectancy in adaptation to stress. Our results suggested that stressful events might be recognized in the same brain regions, that acute stress might affect one brain mechanism, and that expectancy might suppress incoming stressful stimuli.
    Seishin shinkeigaku zasshi = Psychiatria et neurologia Japonica 02/2004; 106(3):365-71.
  • S Tsuji · S Kikkawa · J Horiguchi · H Yamashita · A Kagaya · S Morinobu · S Yamawaki
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    ABSTRACT: We report a case of Meige syndrome with apraxia of lid opening that lasted for about seven months after discontinuation of sulpiride treatment. To our knowledge, this is the first report demonstrating that Meige syndrome with apraxia of lid opening is induced by sulpiride, and that the condition persists.
    Pharmacopsychiatry 08/2002; 35(4):155-6. DOI:10.1055/s-2002-33198 · 1.85 Impact Factor
  • H Yamashita · T Fujikawa · I Yanai · S Morinobu · S Yamawaki
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    ABSTRACT: In this study, we characterized cognitive functioning in patients with major depression and silent cerebral infarction (SCI), as detected by magnetic resonance imaging (MRI), after they had recovered from depression. Thirty-five patients with unipolar depression who experienced the onset of depression after the age of 50 underwent MRI and were classified as SCI(+) (n = 17) or SCI(-) (n = 18). The Wechsler Adult Intelligence Scale-Revised (WAIS-R) and the Uchida-Kraepelin psychodiagnostic test were administered after the patients had recovered from depression. In addition, the intelligence quotient (IQ) and mental speed of the patients in the two groups were compared. The total, verbal and performance IQ scores, as determined by the WAIS-R, were significantly lower in the SCI(+) group than in the SCI(-) group. The mental speed of patients in the SCI(+) group, as assessed by the Uchida-Kraepelin psychodiagnostic test, was almost half that of the SCI(-) group. Our findings provide further evidence that a comprehensive impairment of cognitive functioning, especially a severe reduction in mental speed, remains after recovery from depression in patients with major depression and SCI.
    Neuropsychobiology 02/2002; 45(1):12-8. DOI:10.1159/000048667 · 2.26 Impact Factor
  • K Mori · H Yamashita · M Nagao · J Horiguchi · Shigeto Yamawaki
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    ABSTRACT: It has been suggested that anticholinergic drugs impair immediate memory and working memory in patients with schizophrenia. Opinions remain divided as to the influence of anticholinergic drug withdrawal on the psychopathology and extrapyramidal side effects (EPS) in these patients. In our previous study, regional cerebral blood flow (rCBF) was reduced in all regions of patients taking anticholinergic drugs. Anticholinergic drugs were withdrawn in 21 schizophrenic inpatients. Immediate and verbal working memory, rCBF, psychopathology, and EPS were investigated before and after anticholinergic withdrawal. There was improvement in immediate memory, verbal working memory, and psychopathology, as well as an increase in rCBF after withdrawal from anticholinergic drugs. EPS showed no significant changes. Factors that may predict the improvement of immediate memory after withdrawal of anticholinergic drugs are more severe baseline psychopathology and use of a higher anticholinergic drug dose at baseline. Improvement of working memory may be predicted by a higher baseline rCBF in the left anterior cerebral artery region. Withdrawal from anticholinergics should be considered in schizophrenic patients, and it is important to taper these drugs over at least four weeks.
    Pharmacopsychiatry 02/2002; 35(1):6-11. DOI:10.1055/s-2002-19831 · 1.85 Impact Factor
  • H Yamashita · T Fujikawa · I Yanai · S Morinobu · Shigeto Yamawaki
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    ABSTRACT: Previously, we reported a relationship between silent cerebral infarction (SCI), as detected by magnetic resonance imaging (MRI), and late onset major depression. In the present study, we clarify the clinical features of the depressive phase of patients with major depression and SCI, and their response to antidepressant pharmacotherapy. Using clinical charts, we retrospectively examined patients with depression, who were first admitted for antidepressant pharmacotherapy. All patients were classified according to the MRI findings and the age on admission (older or younger than 50 years) into either the young SCI(-) group (n = 23), the elderly SCI(-) group (n = 27) or the elderly SCI(+) group (n = 20).The characteristics of the clinical features were evaluated at the time of admission, after 2 weeks of treatment and at the time of discharge using the Hamilton rating scale for depression (HAMD). These data were compared between each patient group. No differences in the clinical features, as evaluated by HAMD, were observed between the three groups at the time of admission. However, the mean length of treatment was significantly longer and the treatment response, as evaluated by the total HAMD score, was significantly worse in the elderly SCI(+) group than in the other two groups, when examined after 2 weeks of treatment and at the time of discharge. The elderly SCI(+) group demonstrated higher scores in feelings of guilt, suicide, retardation and hypochondriasis than the young SCI(-) group and the elderly SCI(-) group after two weeks of treatment, and higher scores in early insomnia, late insomnia, somatic anxiety and hypochondriasis at the time of discharge. Our findings suggest that while the presence of SCI does not affect the clinical features observed at the time of admission, it does affect the treatment response to antidepressant pharmacotherapy.
    Neuropsychobiology 02/2001; 44(4):176-82. DOI:10.1159/000054939 · 2.26 Impact Factor
  • J Horiguchi · H Yamashita · Y Kuramoto · S Mizuno
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    ABSTRACT: Neuroleptic-induced akathisia should be definitely diagnosed as acute, tardive, withdrawal, and chronic. The diagnostic assessment must be identified from the subjective report and objective features. Various assessments of measuring akathisia can be clinically used by instrumental methods and rating scales. The pharmacological basis of neuroleptic-induced akathisia is the inhibition of the dopamine receptors in the brain. The pathogenesis of neuroleptic-induced akathisia may involve GABAergic hypoactivity, noradrenergic hyperactivity, and serotonergic dysfunction in CNS. Iron deficiency and hyperglycemia may be risk factors of neuroleptic induced akathisia in relation to the dopamine function in the brain. Neurological disorders may be associated with the development of a syndrome resembling drug-induced akathisia. The lesion of the thalamic nuclei would originally produce the syndrome. The difference between acute and tardive akathisia on the strategy of the drug treatment should be sufficiently comprehended. In particular, the long-term use of anticholinergic drugs and benzodiazepines should not be prevailed.
    Nihon shinkei seishin yakurigaku zasshi = Japanese journal of psychopharmacology 03/1999; 19(1):1-9.
  • J Horiguchi · H Yamashita · S Mizuno · Y Kuramoto · A Kagaya · S Yamawaki · Y Inami
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    ABSTRACT: Nocturnal eating/drinking syndrome secondary to neuroleptic-induced restless legs syndrome (RLS) occurred under treatment with low-dose haloperidol in a 51-year-old female schizophrenic patient. Polysomnographic investigation showed a low level of sleep efficacy, periodic leg movements, and a strict relationship between nocturnal eating episodes and non-rapid eye movement sleep. Her nocturnal eating and RLS were completely inhibited by clonazepam treatment. To our knowledge, this is the first published case of nocturnal eating/drinking syndrome secondary to neuroleptic-induced RLS.
    International Clinical Psychopharmacology 02/1999; 14(1):33-6. · 2.46 Impact Factor
  • J. Horiguchi · H. Yamashita · T. Fujikawa · N. Yokota · S. Yamawaki
    Biological Psychiatry 07/1997; 42(1). DOI:10.1016/S0006-3223(97)87259-9 · 10.26 Impact Factor
  • Biological Psychiatry 07/1997; 42(1). DOI:10.1016/S0006-3223(97)87261-7 · 10.26 Impact Factor