Kiyonobu Komai

Kanazawa University, Kanazawa, Ishikawa, Japan

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Publications (49)139.22 Total impact

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    ABSTRACT: Ataxia with isolated vitamin E deficiency (AVED) is a neurodegenerative disease caused by a mutation in the α-tocopherol transfer protein gene (TTPA). The clinical features of the disease resemble Friedreich's ataxia. However, AVED is associated with low plasma vitamin E levels, which results in compromised antioxidant function. Dysregulation of this lipid-soluble antioxidant vitamin plays a major role in the neurodegeneration observed in AVED. Some AVED patients experience decreased visual acuity. Retinitis pigmentosa is thought to be the main cause of this visual impairment. Although antioxidant levels are important for the prevention of macular degeneration, there have been no reports of macular degeneration in AVED. Here, we describe a patient with AVED with progressive macular degeneration, who carried a novel truncating mutation-c.717 del C (p.D239EfsX25)-in exon 5 of the TTPA gene. These findings suggest that this newly identified mutation results in severely low serum vitamin E levels, which may be associated with the development of retinitis pigmentosa and macular degeneration.
    Journal of the Neurological Sciences 07/2014; 345(1-2). DOI:10.1016/j.jns.2014.07.001 · 2.26 Impact Factor
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    ABSTRACT: Our objective was to determine whether the consumption of green tea, coffee, or black tea influences the incidence of dementia and mild cognitive impairment (MCI) in older people. We conducted a population-based prospective study with Japanese residents aged >60 years from Nakajima, Japan (the Nakajima Project). Participants received an evaluation of cognitive function and blood tests. The consumption of green tea, coffee, and black tea was also evaluated at baseline. Of 723 participants with normal cognitive function at a baseline survey (2007-2008), 490 completed the follow up survey in 2011-2013. The incidence of dementia during the follow-up period (mean ± SD: 4.9±0.9 years) was 5.3%, and that of MCI was 13.1%. The multiple-adjusted odds ratio for the incidence of overall cognitive decline (dementia or MCI) was 0.32 (95% CI: 0.16-0.64) among individuals who consumed green tea every day and 0.47 (95% CI: 0.25-0.86) among those who consumed green tea 1-6 days per week compared with individuals who did not consume green tea at all. The multiple-adjusted odds ratio for the incidence of dementia was 0.26 (95% CI: 0.06-1.06) among individuals who consumed green tea every day compared with those who did not consume green tea at all. No association was found between coffee or black tea consumption and the incidence of dementia or MCI. Our results indicate that green tea consumption is significantly associated with reduced risk of cognitive decline, even after adjustment for possible confounding factors.
    PLoS ONE 05/2014; 9(5):e96013. DOI:10.1371/journal.pone.0096013 · 3.53 Impact Factor
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    ABSTRACT: We herein describe the case of an 81-year-old Japanese woman with neuroleptic malignant syndrome that occurred 36 days after the initiation of combination therapy with tiapride (75 mg/day) and tetrabenazine (12.5 mg/day) for Huntington's disease. The patient had been treated with tiapride or tetrabenazine alone without any adverse effects before the administration of the combination therapy. She also had advanced breast cancer when the combination therapy was initiated. To the best of our knowledge, the occurrence of neuroleptic malignant syndrome due to combination therapy with tetrabenazine and tiapride has not been previously reported. Tetrabenazine should be administered very carefully in combination with other neuroleptic drugs, particularly in patients with a worsening general condition.
    Internal Medicine 01/2014; 53(11):1201-4. DOI:10.2169/internalmedicine.53.1717 · 0.97 Impact Factor
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    ABSTRACT: Objective: To examine whether there are clinical features in Japanese patients with both neurodegenerative diseases and cancers. Methods: We analyzed the clinical characteristics of consecutive Japanese patients with neurodegenerative diseases during the past 5 years, including amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), dementia with Lewy bodies, progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and multiple system atrophy (MSA). Results: Out of 292 patients, 39 patients had cancers, including a past history, as follows: ALS, n = 16; PD, n = 8; PSP, n = 7; CBD, n = 1, and MSA, n = 7. About 10% of patients with neurodegenerative diseases developed cancer after onset of the disease; about 30% of patients with ALS, PD, or PSP occurring with cancers died of cancer. Gastric cancer was most common before the onset of ALS (62.5%) but did not develop after the onset of ALS. Conversely, PD patients frequently developed gastric cancers after the onset of neurological signs (60.0%) in spite of no cancer before the onset of PD. The proportion of breast cancer in MSA (45.5%) was significantly higher than in other neurodegenerative diseases. Conclusion: ALS, PD, or MSA patients with cancer showed clinical characteristics unique to each neurodegenerative disease in Japan compared to other countries. © 2013 S. Karger AG, Basel.
    European Neurology 12/2013; 71(3-4):99-105. DOI:10.1159/000353995 · 1.36 Impact Factor
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    ABSTRACT: Significant differences exist in demographic characteristics between responders and non-responders in population-based studies on mental health and cognitive status, but much less is known regarding differences in the prevalence of dementia and cognitive dysfunction between them. Here we compared the prevalence of dementia and mild cognitive impairment between early responders of a mass brain function examination and delayed responders (non-responders of the mass brain function examination) in a survey of elderly Japanese citizens (≥65 years) to evaluate non-responder bias. All residents in an area of Nakajima, Japan, were considered as potential candidates (n = 783). Participants of a mass brain function examination were considered as "early responders." The cognitive functions of delayed responders were assessed by home visits. To assess the correlation between sociodemographic characteristics and cognitive functions, the early and delayed responders completed the same questionnaires and neuropsychological tests. Delayed responders (n = 320) were significantly older and less educated than the early responders (n = 307). The delayed responders also exhibited a higher frequency of dementia and mild cognitive impairment than the early responders, even when the groups were restricted to the age group 65-89 years. Our results suggest that population-based studies likely underestimate the prevalence of dementia and mild cognitive impairment, especially if the participation rate is low.
    Journal of Alzheimer's disease: JAD 07/2013; 37(4). DOI:10.3233/JAD-130398 · 3.61 Impact Factor
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    ABSTRACT: An increasing elderly population in Japan requires effective cognitive intervention programs for dementia. This study demonstrates the effectiveness of such programs for older adults. The participants were local community-dwelling non-demented older adults and adults with mild cognitive impairment who underwent executive function and group aerobic training. In addition, a non-intervention group participated in activity sessions involving handicraft, Skutt ball matches, and cooking. The four criteria for assessment were cognitive function, instrumental activities of daily living, human relationships, and physical function. The participants in both intervention groups showed a significant improvement in their memory function compared with the non-intervention group. Early rehabilitation intervention using executive function and aerobic training programs may improve memory.
    01/2012; 2(1):69-80. DOI:10.1159/000337224
  • Y Furukawa, K Komai, M Yamada
    European Journal of Neurology 02/2011; 18(2):e26-7. DOI:10.1111/j.1468-1331.2010.03204.x · 3.85 Impact Factor
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    ABSTRACT: We report the case of a woman who developed limb clumsiness in her fifties and gait disturbance in her sixties. She was bedridden after bone fractures at age 75 and showed disorientation, slow eye movement, gaze palsy, ataxic speech, muscle atrophy and weakness, and areflexia with pathological reflex. She died of respiratory failure at age 85. This patient was diagnosed genetically as having spinocerebellar ataxia type 2 (SCA2), and the number of expanded CAG repeats was 41. At autopsy, the brain weighed 965 g, and the brainstem, cerebellum, frontal convexity and spinal cord were atrophic. Neuronal loss and gliosis were severe in the pontine nucleus, inferior olivary nucleus, cerebellar cortex, gracile and cuneate nuclei and moderate in the substantia nigra, cerebellar dentate nucleus, anterior horns of the spinal cord and dorsal root ganglia. Axonal loss was observed in the middle and inferior cerebellar peduncles, pyramidal tract and posterior column of the spinal cord. Senile plaques and neurofibrillary tangles (NFTs) were diffusely found in the cerebrum (plaque stage C; NFT stage IV). Expanded polyglutamine-immunoreactive inclusions in the neuronal cytoplasm were widely distributed in the CNS, and neuronal intranuclear inclusions were observed in the pontine nucleus and cerebral cortex. This patient in this autopsy case is a late-onset and aged patient with SCA2, and this is the first report of SCA2 combined with Alzheimer's disease (AD) pathology. Neuropathological findings in this patient, except for AD pathology, were consistent with those of reported SCA2 cases. However, the olivo-ponto-cerebellar system of this patient was relatively preserved and the cerebellar dentate nucleus was more involved as compared with previously reported cases. These results suggest that age at onset or the number of CAG repeat expansions could correlate with the distribution pattern of SCA2 neurodegeneration.
    Neuropathology 12/2010; 31(5):510-8. DOI:10.1111/j.1440-1789.2010.01176.x · 1.80 Impact Factor
  • Journal of Clinical Neuroscience 01/2010; 17(1):85, 155. DOI:10.1016/j.jocn.2009.05.014 · 1.32 Impact Factor
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    ABSTRACT: Polyethylene glycol-interferon alpha (PEG-IFNalpha) has been used as the standard treatment for hepatitis C virus (HCV) infection. There have been no previous reports of polyradiculoneuropathy with anti-ganglioside antibodies induced by PEG-IFNalpha-2b. We report a 59-year-old man who developed polyradiculoneuropathy during treatment with PEG-IFN alpha-2b for chronic HCV infection. Serum levels of anti-asialo-GM1 (GA1) and anti-GM1 antibodies were elevated. Cessation of therapy with double filtration plasmapheresis resulted in marked improvement in his symptoms accompanied by a reduction in the antibody level. PEG-IFN alpha-2b may induce peripheral neuropathy mediated by anti-GA1 and anti-GM1 antibodies.
    Internal Medicine 02/2009; 48(7):569-72. DOI:10.2169/internalmedicine.48.1794 · 0.97 Impact Factor
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    ABSTRACT: A family with familial amyloid polyneuropathy (FAP) due to a transthyretin (TTR) Leu58Arg mutation was investigated clinicopathologically. The proband presented with sensorimotor-autonomic polyneuropathy and autopsy demonstrated massive amyloid deposition in the peripheral nerves and heart. However, the mother was characterized by carpal tunnel syndrome and ocular vitreous opacities. Thus, there was considerable phenotypic heterogeneity among family members despite the identical TTR genotype.
    Journal of the Neurological Sciences 10/2007; 260(1-2):236-9. DOI:10.1016/j.jns.2007.03.021 · 2.26 Impact Factor
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    ABSTRACT: We report a patient with myasthenia gravis who had neurogenic muscle atrophy in association with external ophthalmoplegia and weakness of the upper limbs. Neurogenic changes in the limb muscles were found on needle electromyography and histological studies. Symptoms improved and atrophy of the limbs diminished after intravenous immunoglobulin and oral corticosteroid therapy. We concluded that functional interruption of the neuromuscular junction caused the neurogenic muscle atrophy and that this was relieved by appropriate therapy.
    Muscle & Nerve 10/2007; 36(3):394-9. DOI:10.1002/mus.20757 · 2.31 Impact Factor
  • European Journal of Neurology 10/2007; 14(9):e14-5. DOI:10.1111/j.1468-1331.2007.01905.x · 3.85 Impact Factor
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    ABSTRACT: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis affects vessels of various diameters in various tissues or organs, sometimes associated with neurological complications. A 77-year-old man developed dysphagia, hoarseness, dysgeusia, gait unsteadiness, and right temporalgia; neurological examination revealed multiple cranial neuropathies. Laboratory studies demonstrated severe inflammatory responses, elevation of perinuclear ANCA, and mild proteinuria. Magnetic resonance imaging of the brain showed dural enhancement in the cerebellar tentorium. Biopsy revealed necrotizing glomerulonephritis in the kidney, and temporal arteritis without giant cells in the temporal artery. The patient was diagnosed with microscopic polyangitis presenting with temporal arteritis and multiple cranial nerve involvement, and was treated with predonisolone, after which the symptoms and laboratory data showed improvement. This is the first case of ANCA-associated vasculitis with pathologically verified lesions in the temporal artery as well as in the kidney. Thus, ANCA-associated vasculitis may simultaneously affect large vessels such as temporal artery, as well as microvessels in the kidney, nerves and other organs.
    Journal of the Neurological Sciences 06/2007; 256(1-2):81-3. DOI:10.1016/j.jns.2007.01.009 · 2.26 Impact Factor
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    Journal of neurology, neurosurgery, and psychiatry 10/2006; 77(9):1094-5. DOI:10.1136/jnnp.2005.086306 · 4.87 Impact Factor
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    ABSTRACT: A subclass of sporadic Creutzfeldt-Jakob disease (sCJD) characterized by onset with visual symptoms (Heidenhain variant) has been reported to belong to the MM1 or MV1 type according to Parchi's classification. The authors report a 65-year-old woman with MM2-cortical sCJD with slowly progressive visual disturbance as the initial symptom. Diffusion-weighted MRIs revealed hyperintensity in both occipital cortices at an early stage.
    Neurology 09/2006; 67(3):531-3. DOI:10.1212/01.wnl.0000228224.35678.60 · 8.30 Impact Factor
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    ABSTRACT: The authors examined blood pressure, glucose, insulin, and neurotensin before and after intake of 75 g glucose with or without voglibose in 28 neurologic patients and 20 healthy controls. Voglibose significantly prevented hypotension and neurotensin increment after glucose intake and had no influence on glucose or insulin increment. These results suggest that voglibose benefits postprandial hypotension.
    Neurology 06/2006; 66(9):1432-4. DOI:10.1212/01.wnl.0000214102.65215.76 · 8.30 Impact Factor
    Annals of the New York Academy of Sciences 02/2006; 841(1):625 - 635. DOI:10.1111/j.1749-6632.1998.tb10994.x · 4.38 Impact Factor
  • Annals of the New York Academy of Sciences 02/2006; 841(1):542 - 545. DOI:10.1111/j.1749-6632.1998.tb10979.x · 4.38 Impact Factor
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    ABSTRACT: We report a 50-year-old woman with primary Sjögren's syndrome (SjS) who initially showed forgetfulness, and later developed disturbance of consciousness. In addition to aseptic meningoencephalitis revealed by cerebrospinal fluid examination and magnetic resonance imaging (MRI), the presence of serum anti-SS-A and anti-SS-B antibodies and inflammatory findings in lip biopsy indicated primary SjS. Fluid attenuated inversion recovery (FLAIR) of MRI revealed well defined small, high signal intensity areas in the cortex involving the subcortical white matter. Corticosteroid therapy resulted in rapid and nearly complete resolution of the cortical lesions with marked improvement of the clinical manifestations. Memory disturbance is a rare initial manifestation in meningoencephalitis associated with SjS. Our patient with SjS showed inflammatory cortical lesions on MRI, which were reversed by corticosteroid therapy.
    Journal of the Neurological Sciences 06/2005; 232(1-2):111-3. DOI:10.1016/j.jns.2005.01.014 · 2.26 Impact Factor

Publication Stats

531 Citations
139.22 Total Impact Points


  • 1998–2011
    • Kanazawa University
      • • Department of Neurology and Neurobiology of Aging
      • • Department of Neurology
      Kanazawa, Ishikawa, Japan
  • 1990–2006
    • Kanazawa Medical University
      • Department of Neurology
      Kanazawa, Ishikawa, Japan