Toshio Okazaki

Oita University, Ōita-shi, Oita-ken, Japan

Are you Toshio Okazaki?

Claim your profile

Publications (8)20.17 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: We aimed to objectively examine the brain perfusion differences between PD, Parkinson variant of multiple system atrophy, and progressive supranuclear palsy. (99m) Tc ethylcysteinate dimer single-photon emission CT (SPECT) was performed in 28 patients with PD, 12 with Parkinson variant of multiple system atrophy, 19 with progressive supranuclear palsy, and 17 age- and sex-matched control subjects. A voxel-by-voxel group analysis, using statistical parametric mapping 8, was performed to detect the differences of regional cerebral blood flow among three diseases and control groups. Regional cerebral blood flow was measured using the noninvasive Patlak plot method and calculated using a fully automated region of interest technique. Progressive supranuclear palsy showed decreased regional cerebral blood flow in the cingulate gyrus and thalamus, whereas Parkinson variant of multiple system atrophy showed decreased regional cerebral blood flow in the cerebellum, compared with other patients and controls. Regional cerebral blood flow in the thalamus could be used to discriminate progressive supranuclear palsy from other diseases and control subjects with high sensitivity. These findings suggest that parkinsonian disorders, such as PD, Parkinson variant of multiple system atrophy, and progressive supranuclear palsy show a distinct SPECT pattern in the frontal cortex, thalamus, and cerebellum. Moreover, the measurements of regional cerebral blood flow in the thalamus and cerebellum may be helpful in screening for the differential diagnosis of parkinsonian syndrome.
    Movement Disorders 08/2011; 26(14):2530-7. · 5.63 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We attempt to evaluate objectively the regional cerebral blood flow (rCBF) changes during long-term donepezil therapy and the relationship between the clinical response and rCBF change in patients with Alzheimer's disease (AD). Thirty-one patients with mild-to-moderate AD (11 men, 20 female; mean age, 76.2 ± 6.7 years) were treated with donepezil and underwent brain perfusion single-photon emission computed tomography (SPECT) twice with an interval of 24.5 ± 4.2 months. The rCBF was calculated using 3-dimensional stereotaxic region of interest template, a fully automated each region of interest technique. We compared the differences in rCBF between baseline and follow-up SPECT studies. Moreover, all patients were divided into stabilized (n = 14) and nonstabilized subgroups (n = 17) based on Mini-Mental State Examination (MMSE) score changes and the changes in rCBF were compared between two subgroups. The mean MMSE score significantly decreased from 20.7 ± 4.6 at baseline to 16.5 ± 6.5 after 2 years. The mean rCBF significantly decreased in the widespread brain regions between the baseline and follow-up SPECT studies. The nonstabilized subgroup showed a significant decrease in rCBF of the parietal and temporal segments compared to the stabilized subgroup. The progression of cognitive deterioration may be related to rCBF affected by the neuropathologic changes of AD.
    Journal of neuroimaging: official journal of the American Society of Neuroimaging 06/2011; 22(3):299-304. · 3.36 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report a case of limbic encephalitis repeated aphasic status epilepticus with periodic lateralized epileptiform discharges (PLEDs). A 51-year-old man developed convulsions, psychiatric symptoms such as anxiety, phobia and ease of anger, and Wernicke's aphasia. Analysis of the cerebrospinal fluid (CSF) showed increase of leukocyte count (148/microl, mononuclear cells). Brain magnetic resonance imaging (MRI) showed hyperintensity lesions in the left medial temporal area and basal frontal area on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images. The electroencephalography (EEG) showed PLEDs over the left hemisphere, occurring at intervals of 0.5-1 Hz. Although his limbic symptoms improved, Wernicke's aphasia occurred periodically with PLEDs appearance. After the administration of antiepileptic drugs, his language performance improved, and PLEDs were completely disappeared. We diagnosed him limbic encephalitis with non-convulsive repeated aphasic status epilepticus with periodic lateralized epileptiform discharges. Aphasic status epilepticus should be considered in the patients with limbic encephalitis, and careful evaluation of aphasia and EEG should be necessary to diagnose of aphasic status epilepticus.
    Rinsho shinkeigaku = Clinical neurology 02/2011; 51(2):135-40.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Subclinical thyroid disease and even variations in thyroid function within the normal range is associated with cognitive function and a risk of Alzheimer disease (AD). Several studies reported the effect of thyroid hormones on cerebral blood flow. The aim of this study was to objectively evaluate regional cerebral blood flow (rCBF) in association with thyroid hormone levels within the normal range in patients with AD. Serum thyroid-stimulating hormone (TSH), free T3, and free T4 levels were measured in 62 patients with AD (23 men and 39 women; age 56 to 91 y; mean age 77.3 y) and 27 control subjects (9 men and 18 women; age 61 to 93 y; mean age 75.8 y). The 99mTc ethylcysteinate dimer single photon emission computed tomography was performed in all subjects. The rCBF in the region of interest was measured by the noninvasive Patlak plot method and calculated using FineSRT, which is a fully automated region of interest technique. No significant correlation was found between thyroid hormone levels and Mini-Mental State Examination scores or global CBF values. Serum levels of TSH, but not free T3 or free T4, were significantly inversely correlated with rCBF in the middle and inferior temporal regions of right cerebral hemisphere in patients with AD. Control subjects showed no significant correlation between thyroid hormone levels and rCBF. Although these findings of a regional relationship must be considers preliminary, this study proposed the hypothesis that altered TSH levels within the normal range may be related to brain perfusion in right temporal region.
    Alzheimer disease and associated disorders 10/2010; 25(2):138-43. · 2.88 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the present study, we compared the patterns of regional cerebral blood flow (rCBF) between cerebellar variant of multiple system atrophy (MSA-C) and the late-onset cortical cerebellar ataxia (LCCA) using FineSRT. We performed (99m)Tc ethylcysteinate dimer (ECD) single-photon emission computed tomography in 11 patients with MSA-C (mean age 65.7 years), 7 patients with LCCA (mean age 62.0 years), and 12 age-matched healthy controls (mean age 64.1 years). The rCBF in the region of interest (ROI) was measured by the noninvasive Patlak plot method and calculated using FineSRT, which is a fully automated the ROI technique. All patients with MSA-C had various degrees of atrophy in the brainstem and middle cerebellar peduncles and 4 of 11 patients showed a clear 'hot cross bun' sign in pontine base on T2-weighted MR images. All patients with LCCA showed the various degrees of atrophy in cerebellum without brainstem. FineSRT revealed the significantly decreased rCBF in the caudate tail, fusiform, lingual, cerebellum, midbrain, and pons in MSA-C group compared with controls. Moreover, MSA-C group showed significantly decreased rCBF in the pons compared with LCCA group. We suggest that a widespread brain involvement is present in patients with MSA-C and the decreased rCBF in the pons may support the differential diagnosis between MSA-C and LCCA.
    Clinical neurology and neurosurgery 10/2009; 111(10):829-34. · 1.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Thyrotropin releasing hormone (TRH) improves cerebellar ataxia and cerebellar perfusion in patients with spinocerebellar degeneration. It is not known whether TRH therapy can improve the cerebellar regional cerebral blood flow (rCBF) or not in patients with cerebellar variant of multiple-system atrophy (MSA-C). Seven patients with MSA-C received TRH intravenously (2 mg/day) for 14 days. Clinical efficacy was assessed using the International Cooperative Ataxia Rating Scale (ICARS) and brain perfusion single photon emission-computed tomography was performed before and after therapy. The rCBF in each region of interest (ROI) was calculated using 3DSRT, a fully automated the ROI technique. The ICARS scores slightly improved in 6 of the 7 patients after TRH therapy, but this was not statistically significant. After TRH therapy, the cerebellar rCBF reduced in the 6 of 7 patients and the mean rCBF in cerebellum also significantly decreased (P=0.029, paired t-test), whereas the rCBF in the precentral segment tend to increase (P=0.048, paired t-test). TRH therapy may be less effective on cerebellar ataxia and cerebellar rCBF in MSA-C. The 3DSRT program may be useful for the evaluation of the efficacy of TRH therapy on cerebral blood flow.
    Journal of neuroimaging: official journal of the American Society of Neuroimaging 09/2009; 21(2):132-7. · 3.36 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Thyrotropin releasing hormone (TRH) therapy improves cerebellar ataxia in patients with spinocerebellar degeneration (SCD). We investigated the effect of TRH on regional cerebral blood flow (rCBF) using the fully automated region of interest (ROI) technique, 3DSRT. Ten patients with SCD received TRH intravenously (2 mg/day) for 14 days and underwent brain perfusion single photon emission computed tomography before and after therapy. Clinical efficacy was assessed using the International Cooperative Ataxia Rating Scale (ICARS). The rCBF in each ROI was measured using the noninvasive Patlak plot method and calculated using 3DSRT. TRH significantly improved the ICARS scores and increased rCBF in the callosomarginal segment and cerebellum. Cerebellar rCBF increased in 4 of 5 patients with improved ICARS scores and in 3 of 5 patients without improved ICARS scores after TRH therapy. The correlation between the change in cerebellar rCBF and the improved ICARS score, however, was not significant. These findings indicate that TRH therapy may increase cerebellar rCBF in some patients with cerebellar forms of SCD and that 3DSRT may be useful for evaluating the efficacy of TRH for increasing CBF. The beneficial effects of TRH may be due to increased cerebellar rCBF or the increased rCBF may be a secondary effect of TRH therapy.
    Journal of the neurological sciences 04/2009; 281(1-2):93-8. · 2.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Here we report two cases of pathologically confirmed tumor-like demyelinating lesions. In comparison with common primary demyelinating diseases, our cases demonstrated atypical radiologic features, such as a large monofocal lesion with mild brain edema, and open ring-like or focal enhancement on magnetic resonance images, suggesting brain tumors. The clinical manifestations included focal neurologic signs due to the lesions, monophasic episodes without relapse over a long follow-up period, and efficacy of oral corticosteroid therapy. Histological analysis of brain biopsy specimens showed the inflammatory demyelination and preserved axons without tumor cells. The present cases suggest the importance of considering inflammatory demyelinating disease in the different diagnosis of monofocal tumor-like lesion.
    Clinical neurology and neurosurgery 01/2009; 111(3):296-9. · 1.30 Impact Factor