Hiroo Terashi

Tokyo Medical University, Edo, Tōkyō, Japan

Are you Hiroo Terashi?

Claim your profile

Publications (6)5.32 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Turnover is a typical intermittent body movement while asleep. Exploring its behavior may provide insights into the mechanisms and management of sleep. However, little is understood about the dynamic nature of turnover in healthy humans and how it can be modified in disease. Here we present a detailed analysis of turnover signals that are collected by accelerometry from healthy elderly subjects and age-matched patients with neurodegenerative disorders such as Parkinson's disease. In healthy subjects, the time intervals between consecutive turnover events exhibit a well-separated bimodal distribution with one mode at ⩽10 s and the other at ⩾100 s, whereas such bimodality tends to disappear in neurodegenerative patients. The discovery of bimodality and fine temporal structures (⩽10 s) is a contribution that is not revealed by conventional sleep recordings with less time resolution (≈30 s). Moreover, we estimate the scaling exponent of the interval fluctuations, which also shows a clear difference between healthy subjects and patients. We incorporate these experimental results into a computational model of human decision making. A decision is to be made at each simulation step between two choices: to keep on sleeping or to make a turnover, the selection of which is determined dynamically by comparing a pair of random numbers assigned to each choice. This decision is weighted by a single parameter that reflects the depth of sleep. The resulting simulated behavior accurately replicates many aspects of observed turnover patterns, including the appearance or disappearance of bimodality and leads to several predictions, suggesting that the depth parameter may be useful as a quantitative measure for differentiating between normal and pathological sleep. These findings have significant clinical implications and may pave the way for the development of practical sleep assessment technologies.
    Physical Review E 03/2014; 89(3-1):032721. · 2.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Few reports have objectively assessed gait patterns of Parkinson's disease (PD) patients in their daily lives. We investigated the mean gait cycle and mean gait acceleration using a portable gait rhythmogram (PGR). Method: We continuously recorded PGR measurements for 24 h in 64 PD patients with the ability to independently engage in activities of daily living. Results: There was no significant difference in the mean gait cycle between PD patients and normal controls. However, the mean gait cycle was significantly faster in PD patients in the modified Hoehn and Yahr stage 1.5 than those in stages 2.5-3.0. The mean gait acceleration in PD patients was significantly less than in normal controls, but there were no significant differences among the stage groups. Conclusion: The results suggest that the cycle and acceleration of gait movements are controlled independently and that disturbances in these movements have different clinical courses in PD.
    European Neurology 12/2012; 69(3):134-141. · 1.50 Impact Factor
  • Hiroo Terashi, Yohei Ishimura, Hiroya Utsumi
    [Show abstract] [Hide abstract]
    ABSTRACT: Although freezing of gait (FOG) is reportedly caused by cerebrovascular disease, few studies have examined its pathology. We examined regional cerebral blood flow (rCBF) patterns in patients with FOG resulting from chronic lacunar infarction using single-photon emission computed tomography (SPECT). Among patients with chronic lacunar infarction treated at our outpatient unit, we performed N-isopropyl-p-[(123)I]-iodoamphetamine SPECT in seven patients with FOG (FOG group) and in 20 patients without FOG (non-FOG group). We analyzed and compared the SPECT data using three-dimensional stereotactic surface projections of the two groups. On z-score maps, the FOG group showed a significant reduction in rCBF in the bilateral anterior cingulate cortices compared with the non-FOG group. The mean z-score for the bilateral cingulate gyri was significantly higher in the FOG group than in the non-FOG group (p < .01). When the cingulate gyrus data of the anterior and posterior subregions were analyzed on a region-by-region basis, the mean z-score for the left anterior cingulate gyrus was significantly higher than that for the right cingulate gyrus (p < .05). These results suggest that anterior cingulate cortex dysfunction may be involved in the pathology of FOG in patients with chronic lacunar infarction.
    The International journal of neuroscience 03/2012; 122(8):423-30. · 0.86 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To quantify gait bradykinesia during daily activity in patients with Parkinson's disease (PD), we measured movement-induced accelerations over more than 24h in 50 patients with PD and 17 age-matched normal controls, using a new device, the portable gait rhythmogram. Acceleration values induced by various movements, averaged each 10 min, exhibited a gamma distribution. The mean value of the distribution curve was used as an index of the "amount of overall movement per 24h". Characteristic changes were observed in both the gait cycle and gait acceleration. During hypokinesia, the gait cycle became either faster or slower. A number of patients with marked akinesia/bradykinesia showed a reduced and narrow range of gait acceleration, i.e., a range of floor reaction forces. The results suggest that assessment of the combination of changes in gait cycle and gait acceleration can quantitatively define the severity of gait bradykinesia.
    Acta medica Okayama 02/2012; 66(1):31-40. · 0.65 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To examine the range of gait acceleration and cycle in daily walking of patients with Parkinson's disease (PD), we compared the gait of 40 patients with PD and 17 normal controls by using a newly developed long-term monitoring device that extracts gait-related accelerations from overall movements-related accelerations. The range of change in gait acceleration, relative to the control, was less than 75% in 12 patients. The range of change in gait cycle was less than 75% in 8 patients. The range of changes in both parameters was less than 75% in 4 patients. The results suggest narrow changes in gait parameters in PD.
    ISRN neurology. 01/2012; 2012:306816.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In advanced-stage Parkinson's disease (PD), motor fluctuation is a frequent and disabling problem. Assessment of motor fluctuation depends on patient's subjective self-statement. We examined whether the subjective fluctuation matched the objective motor fluctuation defined by gait disorders. Using a new device, the portable gait rhythmogram, we recorded gait cadence and acceleration continuously over the 24-hour period in 54 patients with PD and 17 normal controls, for the quantitative evaluation of motor fluctuation. The patients were asked to estimate motor fluctuation every hour. In 44 of 54 patients, changes in the cadence were associated with simultaneous changes in acceleration. We examined the subjective fluctuation in these 44 patients who were confirmed to have motor fluctuation. Nineteen (82.7%) of 23 patients who felt no fluctuation showed distinct gait disorders. During off time, they walked with marked short or bradykinetic stepping. No matching changes were observed in either the cadence or acceleration in 11 (52.4%) of 21 patients who perceived motor fluctuation. No synchronization was noted in 30 (68.2%) of the 44 patients, between the times of subjectively assessed motor fluctuation and those of quantitative analysis of gait disorder. This discrepancy suggests that the objective continuous recording of the cadence and acceleration is necessary to understand motor fluctuation.
    ISRN neurology. 01/2012; 2012:372030.