Shunsaku Hirai

The University of Tokyo, 白山, Tōkyō, Japan

Are you Shunsaku Hirai?

Claim your profile

Publications (49)145.7 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We retrospectively studied the relationship between linear hyperintensity objects (LHOs) on T(2)-weighted magnetic resonance images (MRI) in the cerebral white matter and the occurrence of hypertensive intracerebral hemorrhage (HIH). Forty-nine hypertensive patients with a fixed imaging condition MRI were classified into three groups: HIH (n = 17), ischemic stroke due to hypertensive vasculopathy (n = 19), and hypertension only (n = 13). After assessing clinical and radiological background information among these groups and the reliability of LHO measurements, polynomial logistic regression analysis was used to identify the factors relating to HIH. HIH had a significantly higher LHO number (p = 0.002) and larger diameter (p = 0.007). The LHO number showed an excellent interrater (kappa = 0.91, 95% CI = 0.87-0.94, SEM = 6.2%) and intrarater reliability (kappa = 0.95, 95% CI= 0.92-0.97, SEM = 4.8%), and was the most significant independent indicator of HIH (OR = 1.29, 95% CI = 1.05-1.60, p = 0.017). The number of microbleeds was an additional indicator (OR = 3.73, 95% CI = 1.10-12.65, p = 0.034). LHOs are closely linked to HIH. A prospective, longitudinal study is needed to clarify whether LHOs can predict HIH.
    Full-text · Article · Feb 2004 · Cerebrovascular Diseases
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the usefulness of central retinal artery (CRA) Doppler flowmetry in patients with cerebral small-vessel disease (SVD). CRA Doppler flowmetry was performed in 103 SVD patients who underwent MRI. Sixty-four adjusted control subjects were also registered. We assessed average CRA flow parameter values for both eyes with the clinical and MRI findings. Each Doppler flowmetry was performed within 5 minutes. Patients with SVD had significantly lower end-diastolic and mean velocities of the CRA than control subjects; they also had higher pulsatility and resistive indexes. Multivariate analysis showed that the number of small infarcts was an independent predictor of peak systolic and mean velocities. Grade of periventricular hyperintensities was an additional independent predictor of peak systolic and mean velocities, whereas the number of small infarcts was predictive of end-diastolic velocity. Flow parameters may be useful for the quantitative assessment of SVD severity.
    Full-text · Article · Aug 2003 · Stroke
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 70-year-old, right-handed man was admitted to our hospital for his sudden-onset topographical disorientation. He failed to find his way to familiar places, but he knew distance and direction to the places. Neurological examination revealed homonymous left-upper quadrantanopsia on Goldmann perimeter and hypoesthesia over the left side of his body. Magnetic resonance imaging showed an abnormal intensity area at the right medial temporo-occipital region, due to the infarct of the right posterior cerebral arterial territory. The neuropsychological examination revealed agnosia for streets, and prosopagnosia without any other disturbance of visual perception. Both visual and topographical memories were intact. It is suggested that, in this case, the agnosia for streets was caused by impairment of recognizing familiar streets and houses or disconnection between their recognition and memory.
    No preview · Article · Jul 2003 · Rinsho shinkeigaku = Clinical neurology

  • No preview · Article · Jan 2003 · Internal Medicine

  • No preview · Article · Nov 2002 · Nō to shinkei = Brain and nerve
  • [Show abstract] [Hide abstract]
    ABSTRACT: Alpha-synuclein(alpha-S) and ubiquitin(Ub) are constituents of the Lewy bodies (LBs), composed of fibrillary structures. To clarify morphological heterogeneity of LBs, we looked for localization of these epitopes in relation to fibrillary structure possibly detectable by a fluorochrome, thiazin red (TR). On the sections of the substantia nigra (SN) and the cingulate gyrus (CG) obtained from Parkinson's disease brains, double amplification by CARD fluorescent immunohistochemistry with anti-alpha-S monoclonal (LB509) and anti-Ub polyclonal antibodies was performed, followed by staining with TR. These triple-labeled images were captured by a confocal laser microscope and subsequently stained with Campbell-Switzer method, a silver staining specific for LBs. Staining profiles of LBs were different between those in the SN and in the CG. Immunolabeling either with the anti-alpha-S or anti-Ub antibody was diffuse without halo structure in LBs of CG. In addition to this diffuse staining, a lot of LBs of SN exhibited a halo structure immunopositive for alpha-S and Ub, probably representing later stages of LB evolution. Irrespective of the presence of this halo structure, the TR signal was always concentrated in the center of LBs, as the silver-stained material was, suggesting that fibrillary components in the central portion of LBs undergo some conformational changes detectable by TR and the silver-staining. This technique reveals different epitopes in relation to LB evolution in vivo. Heterogeneity in staining profile of LBs, as clarified by this method, may represent evolutional changes of LBs, related to conformational states of their constituents.
    No preview · Article · Oct 2002 · Experimental Neurology
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 79-year-old woman, with no immune deficit, had presented progressive visual disturbance, diplopia and ptosis of her left eye over 2 weeks. T1-weighted MR images with gadolinium showed a heterogeneously enhanced lesion extending from the left orbital apex along the optic nerve to the cavernous sinus. Although we could not detect fungus by a transsphenoidal biopsy, we suspected fungal infection because of high level of galactomanan antigen in serum. Despite antifungal chemotherapy, her symptoms did not improve. CT image on day 40 showed an aneurysm in the left internal carotid artery, on day 43 cerebral infarction in the left internal carotid artery distribution and on day 45 she died. Autopsy disclosed that aspergillus hyphae invaded the left sphenoid sinus, cavernous sinus and wall of the aneurysm. In this case, fungal infection in the frontal skull base including orbital apex caused mycotic aneurysm in the intracavernous portion of the left internal carotid artery. Skull base aspergillosis presenting orbital apex syndrome is itself rare and in addition, the occurrence of cerebral infarction in the mycotic aneurysm has hardly been reported. We should have cerebrovascular disease in mind as a complication of CNS aspergillosis.
    No preview · Article · Sep 2002 · Rinsho shinkeigaku = Clinical neurology
  • Y Ueki · E Isozaki · Y Miyazaki · R Koide · T Shimizu · K Yagi · S Hirai
    [Show abstract] [Hide abstract]
    ABSTRACT: We report two patients with chronic acquired hepatocerebral degeneration (CAHD) who showed neurological and radiological improvement after the administration of branched-chain amino acids (BAA). The first patient with chronic hepatitis C presented with progressive parkinsonism for 7 months, whereas the second patient with liver cirrhosis presented with progressive ataxia for 15 months. T1-weighted magnetic resonance imaging (MRI) showed symmetric high intensity signals in the lenticular nuclei in both patients. In the first patient, single photon emission computed tomography (SPECT) disclosed a marked decrease in cerebral blood flow in the parieto-occipital regions. In the second patient, T2-weighted MRI demonstrated symmetric high intensity signals in the deep cerebral and cerebellar white matter. After the administration of BAA, their neurological signs and radiological abnormalities markedly improved in both patients. CAHD might be a reversible and treatable disorder where aromatic amino acids are deeply involved in its pathogenesis.
    No preview · Article · Sep 2002 · Acta Neurologica Scandinavica
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Following a hemispheric stroke, various degrees of neuronal reorganization around the lesion occur immediately after disease onset and thereafter up to several months. These include transcallosal excitability, changes of the intact motor cortex and ipsilateral motor responses after transcranial magnetic stimulation (TMS) on the intact hemisphere. To elucidate the relationship between lesion localization and motor cortex excitability (intracortical inhibition; ICI) in the intact hemisphere, we applied a paired conditioning-test TMS paradigm in 12 patients with unilateral cortical stroke (cortical group) and nine patients with subcortical stroke caudal to the corpus callosum (subcortical group), with interstimulus intervals varying from 1 to 10 ms. All patients exhibited unilateral complete hand palsy. ICI was significantly less in the cortical group than in age-matched healthy control subjects. It was especially more marked in the cortical group patients with a disease duration of less than 4 months after onset. Patients in the cortical group with a duration longer than 4 months showed a tendency for ICI to be normalized, and there was a significant correlation between ICI and disease duration. Patients in the subcortical group showed normal excitability curves. All patients in the cortical group showed no transcallosal inhibition (TCI) in the active unaffected hand muscle after TMS of the affected motor cortex, whereas all the subcortical patients showed some TCI. No ipsilateral motor responses were elicited in the paretic hand in any of the patients. The reduced ICI in the cortical group might have been a result of disruption of TCI. The normalization of ICI in the patients with longer disease duration and the normal ICI in the subcortical group patients do not support the functional significance of motor cortex hyperexcitability in the unaffected hemisphere, at least in a patient population with poor motor recovery.
    Preview · Article · Sep 2002 · Brain
  • [Show abstract] [Hide abstract]
    ABSTRACT: While multiple system atrophy (MSA) is frequently associated with vocal cord paralysis (VCP) causing severe respiratory failure, it is still unknown whether hereditary types of spinocerebellar degeneration develop similar laryngeal paralysis. We analyzed the laryngeal function from the viewpoints of fiberoptic laryngoscopy and laryngeal myopathology and then attempted to clarify the difference of the mechanism of VCP among the patients with spinocerebellar ataxia type 1 (SCA 1), type 3 (SCA 3), and MSA. Seven patients with SCA 1, nineteen with SCA 3, and eleven with MSA were studied. Vocal cord movement was analyzed by fiberoptic laryngoscopy during wakefulness and diazepam-induced sleep (sleep load test). Paraffin-embedded sections or cryosections of the intrinsic laryngeal muscles from five autopsied cases (one with SCA 1 and four with SCA 3) were histologically examined. VCP was found in two of the seven SCA 1 patients (29%), three of the nineteen SCA 3 patients (16%), and in nine of the eleven MSA patients (82%). VCP observed in SCA 1 and SCA 3 was various in the severity and showed no exacerbation on sleep load test in all of the eight patients but one SCA 3 patient. In this patient, the findings of fiberoptic laryngoscopy were quite similar to those found in MSA. All the intrinsic laryngeal muscles including cricothyroid (CT), interarytenoid (IA), and posterior cricoarytenoid (PCA) muscles showed neurogenic atrophy in one autopsied SCA 1 and four SCA 3 patients. Our conclusion is that VCP in SCA 1 and SCA 3 contrasts with that in MSA in its occurrence, response to the sleep load test, and the distribution of the neurogenic abnormalities among the intrinsic laryngeal muscles.
    No preview · Article · Jun 2002 · Journal of the Neurological Sciences
  • Takae Ohno · Katsuhiko Takeda · Shuichi Kato · Shunsaku Hirai

    No preview · Article · Feb 2002 · Journal of Neurology
  • [Show abstract] [Hide abstract]
    ABSTRACT: To elucidate underlying abnormalities of the masseter motor system in amyotrophic lateral sclerosis (ALS). We recorded biphasic EMG suppressions of the masseter muscle (silent or inhibitory periods 1 and 2) after electrical stimulation of the mental nerve during maximum clenching of the teeth in 16 ALS patients and 15 healthy control subjects. We also examined the recovery cycle of the silent periods by delivering paired stimuli with an interstimulus interval of 250 ms. Silent period 1 in the patients was not significantly different from that in control subjects, whereas silent period 2 (as measured by its area on the graph) was increased in the patients, especially with exaggerated jaw jerk. Only two patients showed absence of silent period 2. The recovery cycle of silent period 2 in the subgroup of patients with exaggerated jaw jerk was significantly lower than the control value. The abnormalities of the masseter inhibitory reflex in ALS could be ascribable to involvement of the corticobulbar or corticoreticular tract projecting to the inhibitory interneurons mediating silent period 2.
    No preview · Article · Jan 2002 · Amyotrophic Lateral Sclerosis
  • [Show abstract] [Hide abstract]
    ABSTRACT: SJL/J mice have been subjected to immunization with wide varieties of antigens to produce models of autoimmune disorders including experimental myositis. They also have a defect in dysferlin gene and spontaneously develop muscle fiber degeneration, a condition akin to limb-girdle type muscular dystrophy and Miyoshi myopathy. To know whether muscle inflammation of SJL mice after immunization with muscle fractions really represents immune-mediated myositis or no more than an epiphenomenon of muscle degeneration due to dysferlin defect, we studied immunological parameters after immunization with rabbit myosin B fraction. Initial infiltration of macrophages and CD4+ lymphocytes on day 11 was followed by increase in number of CD8+ cells. Such increase was not observed in the nontreated and adjuvant controls. Some infiltrating cells were interferon gamma (IFN-gamma) positive. Furthermore, increased expression of the signal transducers and activator of transcription 1 (STAT-1) and interferon regulatory factor 1 (IRF-1) mRNA was shown in the first 2 weeks. These results indicate Th1 system activity in the muscle, rather than simple dysferlin deficiency, particularly 1-3 weeks after immunization. Thus it is concluded that an immune-mediated myositis is taking place at this stage. This model can be helpful in understanding pathomechanisms involved in the early stage of human myositides. It has also important implications concerning immune reactions associated with transplantation or gene therapy for muscular dystrophies.
    No preview · Article · Nov 2001 · Journal of Neuroimmunology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In an immunohistochemical study of Marinesco bodies--a neuronal intranuclear inclusion often seen in neurons of the substantia nigra of patients with hepatic encephalopathy--it was shown that one of the polyglutamine proteins, ataxin-3, is preferentially recruited into this inclusion, whereas other polyglutamine proteins (ataxin-2 and TATA box-binding protein) are not. This suggests that recruitment of each of the polyglutamine proteins may be differently regulated. Because this nuclear inclusion is thought to be formed in response to cellular stress, as occurs in hepatic encephalopathy, even in the absence of an expanded CAG/polyglutamine repeat, recruitment of ataxin-3 and ubiquitin into Marinesco bodies may represent a cellular response to noxious external stimuli unrelated to expanded CAG/polyglutamine.
    Full-text · Article · Nov 2001 · Journal of Neurology Neurosurgery & Psychiatry
  • [Show abstract] [Hide abstract]
    ABSTRACT: A case of autosomal dominant limb-girdle muscular dystrophy with atrioventricular conduction block (LGMD1B) has been documented. In this family, 13 members, nine males and four females, had cardiac arrhythmia requiring pacemakers. The proband, a 67-year-old male, had longstanding proximal muscle weakness later associated with cardiac arrhythmia but showed neither rigid spine nor joint contracture. His muscle enzymes were within normal range and muscle biopsy showed myopathic changes. Gene analysis of the proband revealed Tyr481His mutation in the exon 8 of lamin A/C (LMNA) gene which is adjacent to the codon mutated in reported cases of familial partial lipodystrophy. This is the first report of muscular dystrophy shown to have a mutation of LMNA in a Japanese family as well as the first case of missense mutation in the exon 8 with LGMD1B phenotype.
    No preview · Article · Oct 2001 · Neuromuscular Disorders
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 72-year-old man presented with paroxysmal and transient involuntary movements, or "limb shaking". The attacks occurred alternately from one side of the body to the other and ceased spontaneously. Surface EMG study showed synchronous grouping discharges in multiple limb muscles, being compatible with hemiballism-hemichorea. Cerebral angiography demonstrated marked stenosis of the bilateral internal carotid arteries. Bilateral carotid endarterectomy led to complete disappearance of the involuntary movements. Alternating paroxysmal hemiballismhemichorea might be a transient ischemic attack, and alternating striatal dysfunction induced by cerebral hemodynamic or microembolic ischemia probably plays a central role in the occurrence of such involuntary movements.
    No preview · Article · Sep 2001 · Internal Medicine
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We report here a 12-year-old patient with unilateral cortical dysgenesis and intractable simple partial seizure in his left arm, who underwent multiple subpial transection (MST) in the right cerebral cortex including the primary motor cortex. We investigated motor cortical excitability using multimodal transcranial magnetic stimulation (TMS) before and 1 month after MST, in which surgical cortical incisions were made with strokes 5 mm apart and 4 mm deep. Preoperative TMS studies showed hyperexcitability in the affected motor cortex as abnormally prolonged muscle responses to TMS with a wide cortical motor map, which were markedly reduced following the operation. The preoperative motor evoked potentials were large and polyphasic, and consisted of early and late components. The late component was completely abolished after MST, suggesting that this component might be due to activation of the corticospinal tract neurones by long recurrent axon branches of dysplastic excitatory pyramidal neurones, which were cut by MST, or by delayed, polysynaptic intracortical conduction with marked temporal dispersion. Intracortical inhibition in the affected motor cortex was also disrupted preoperatively and improved after MST. Postoperative recruitment order of muscle responses to TMS was bilaterally symmetrical, indicating that MST did not interfere with the function of the corticospinal tract neurones. The patient showed fair motor recovery and good seizure control after the operation. These results of TMS studies demonstrated the remarkable effectiveness of MST not only on intractable seizure but also on abnormal motor cortical organization and hyperexcitability in cortical dysgenesis.
    Preview · Article · Aug 2001 · Brain
  • R Koide · M Bandoh · E Isozaki · S Hirai
    [Show abstract] [Hide abstract]
    ABSTRACT: We report a 74-year-old right-handed man with visual agnosia for picture due to right occipital lobe infarction. The patient had a remarkable impairment in visual recognition for standardized pictures made by Snodgrass and Vanderwart, in addition to left hemianopsia, left visuospatial neglect, and mild prosopagnosia. The visual agnosia for picture was generally recognized as a mild-type of the visual object agnosia, which was extremely rare in the patients with right occipital lesion. We discussed the mechanism of the visual agnosia in the right occipital lesion. Therefore, it raises the possibility that the broad impairment of the right occipital artery territory including parahippocampal gyrus as well as corpus callosum can cause the visual agnosia for picture.
    No preview · Article · Jul 2001 · Nō to shinkei = Brain and nerve
  • [Show abstract] [Hide abstract]
    ABSTRACT: We assessed subclinical sympathetic hyperactivity in amyotrophic lateral sclerosis (ALS) patients, which might be followed by an autonomic spell leading to circulatory collapse, or sudden death as the disease progresses, and investigated the effect of tamsulosin hydrochloride (TSHC) on sympathetic hyperactivity. We measured the plasma norepinephrine (NE) concentrations of 41 ALS patients and 10 normal controls. TSHC, a selective alpha 1 blocker. was then administered to 10 ALS patients who had high plasma NE and to the 10 normal controls. Subsequent plasma NE change was evaluated for the possible alleviating effect of TSHC on subclinical sympathetic hyperactivity in ALS. Plasma NE was high in 20 of the ALS patients (48.8%), but had no relation to respiratory problems, which supports the previous speculation that plasma NE increases in ALS are not secondary to respiratory deficit, but reflect the primary pathomechanism of the disease. ALS patients showed a marked decrease in the NE concentration after TSHC administration, whereas there was no change in the controls. In conclusion, TSHC may be useful for suppressing central sympathetic hyperactivity, presumably the primary pathomechanism in ALS, and for preventing autonomic spells during the advanced stage of the disease.
    No preview · Article · May 2001 · Autonomic Neuroscience
  • K Aoki · A Kawata · M Suda · S Hirai
    [Show abstract] [Hide abstract]
    ABSTRACT: To clarify the clinical features of genetically unclassified autosomal dominant spinocerebellar ataxias (AD-SCAs) treated in our hospital, we retrospectively analyzed the clinical findings of patients who could not be molecularly classified into SCA types 1 through 3, 6 through 8, 12 and dentato-rubro-pallido-luysian atrophy (DRPLA). The clinical findings of 19 patients from 15 different families which form 14 percent of all patients with different types of AD-SCAs (136 patients, 105 families) were collected. Based on these, 17 patients from 13 families showed late-onset (mean age at onset: 46 years old) and slowly progressive truncal and limb ataxias of cerebellar origin. Some of them showed gaze-evoked nystagmus, increased deep reflexes without Babinski sign, tremor, mildly decreased vibration sense and mild rectourinary disturbances. All but one were still ambulatory after 15 years of their mean disease duration. An earlier disease onset in successive generations was observed in 8 families. Brain MRIs revealed cerebellar atrophy predominantly in the anterior vermis in all the patients and mild brainstem atrophy in only 3 patients. Although the clinical phenotype manifested by most of the genetically unclassified AD-SCAs is similar to that of SCA6, whether the phenotype is caused by expansion of triplet repeats or some mutations in a single gene or different mutations in various genes is still unclarified.
    No preview · Article · Feb 2001 · Rinsho shinkeigaku = Clinical neurology

Publication Stats

1k Citations
145.70 Total Impact Points


  • 2002
    • The University of Tokyo
      • Department of Neurology
      白山, Tōkyō, Japan
    • Tokyo Metropolitan Police Hospital
      Edo, Tōkyō, Japan
  • 1998
    • Tokyo Metropolitan Hiroo Hospital
      Edo, Tokyo, Japan