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ABSTRACT: We studied changes in water diffusion in cerebral white matter in 10 patients with Binswanger's disease (BD), 8 patients with Alzheimer's disease (AD) who had periventricular hyperintensity lesions on T2-weighted images, and 8 age-matched controls. The apparent diffusion coefficients measured in the anterior and posterior white matter were significantly higher in the patients than in the controls, but there was no significant difference between patients with BD and those with AD. The anisotropy ratios, difined as diffusion perpendicular to the nerve fiber direction, were higher in the patients than in the controls. The anisotropy ratio in the anterior white matter was significantly higher in patients with BD than in those with AD, while in the posterior white matter the ratio was significantly higher in patients with AD than in those with BD. These results suggest that in BD and AD cerebral white matter lesions such as periventricular hyperintensity lesions reflect a loss of myelin and axons, and that loss of myelin occurs preferentially in the anterior white matter in BD and in the posterior white matter in AD.
Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 11/1996; 33(10):761-7.
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ABSTRACT: To investigate changes in water diffusion in the cerebral white matter in Alzheimer-type dementia (AD), diffusion MRI studies were performed on 11 patients with AD without hyperintensity lesions on T2-weighted images, and 10 age-matched controls. In the anterior and posterior white matter around the lateral ventricule, and the splenium of the corpus callosum, the apparent diffusion coefficients (ADCs), in which the diffusion gradient was applied perpendicular to the predominant fiber direction, were significantly higher in patients with AD than in the controls. However, those in which the diffusion gradient was applied parallel to the predominant fiber direction, there were no significant difference in ADCs between patients and controls. Therefore, diffusional anisotropy was lost in the white matter. These results suggest that demyelination occurs in patients with AD even in apparently normal white matter (without signal abnormalitis). Degeneration related to grey matter encephalopathy may be a possible explanation of the demyelinating process in the white matter.
Rinsho shinkeigaku = Clinical neurology 08/1996; 36(7):909-11.
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ABSTRACT: MR diffusion-weighted imaging was performed to investigate changes in water diffusion in patients with cerebral infarction, and diffusion-weighted images (DWI) were compared with T2-weighted images (T2WI). Acute and subacute infarcts were seen as areas of high intensity on DWI and showed lower apparent diffusion coefficients (ADCs), while chronic infarcts showed a relative increase in ADCs. The relative ADC increased progressively over time, becoming renormalized at 3 to 4 weeks, and was elevated in the chronic state. On DWI, infarcts as small as 5 to 6 mm in diameter and lesions adjacent to the ventricular or subarachnoid space could be readily identified. DWI was useful for distinguishing acute lesions from chronic lesions in patients with multiple cerebral infarction, and provided valuable pathophysiologic information on the course of ischemic stroke evolution.
Nō to shinkei = Brain and nerve 05/1996; 48(4):345-9.
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ABSTRACT: We performed diffusion MRI studies in 14 patients with extensive ischemic leukoencephalopathy, including 9 with dementia (diagnosed as Binswanger's disease), and 5 without dementia, and 8 age-matched controls. Apparent diffusion coefficients (ADCs) in anterior and posterior periventricular white matter were significantly higher in demented and non-demented patients than in the controls, and diffusion anisotropy disappeared in patients because of the high ratio of the diffusion coefficients perpendicular to the nerve fibers to those parallel to the nerve fibers. ADCs in the corpus callosum were significantly higher in demented patients that in non-demented patients and controls. Therefore, diffusion anisotropy disappeared only in demented (Binswanger's disease) patients. These results suggest that the cerebral white matter lesions in Binswanger's disease reflect a decrease of nerve fibers and diffuse myelin loss, and that the loss of nerve fibers in the corpus callosum may play a role in inducing cognitive decline. Diffusion MRI may be useful in the pathophysiological evaluation of cerebral white matter lesions.
Rinsho shinkeigaku = Clinical neurology 04/1996; 36(3):442-50.
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ABSTRACT: Cerebral blood flow (CBF) at rest was measured by 123I-IMP SPECT and the standing test was conducted by 99mTc-HMPAO SEPCT in patients with dementia of Alzheimer's type (DAT) and vascular dementia (VD) in order to evaluate cerebral autoregulation and to consider the diagnostic significance of this determination and test. CBF at rest decreased significantly in all regions in the DAT and VD groups compared to the control groups (healthy aged persons, group C). The value of mean CBF also decreased significantly in the DAT (40.1 micromilligrams/100 g/min) and VD groups (41.3) as compared to group C (51.0). In the DAT groups, the CBF was significantly lower in the parietal region compared to VD groups, and CBF and Hasegawa's dementia score showed a positive correlation in the temporal and parietal regions. Decreases in blood pressure upon standing were about 10 mmHg in all three groups, but the decrease rate in mean CBF was significantly greater in the VD groups (20.2%) than in the C (5.0%) and DAT groups (4.0%). The dysautoregulation index (D.I. delta; % CBF mmHg), used as a measurement of cerebral autoregulation, was significantly higher in the VD groups (1.7) than in the C(0.5) and DAT groups (0.3). This index made it possible to make differential diagnosis in some patients in whom it was impossible using CBF at rest, probably due to impaired cerebral autoregulation and atherosclerotic changes in VD patients. Our findings suggest that D.I. provides information on the condition of patients that cannot be obtained with CBF at rest and assists in differential diagnosis.
Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 03/1996; 33(2):95-104.
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ABSTRACT: To examine the correlation between neuropsychological and cerebral blood flow changes in Alzheimer-type dementia (AD), we studied 17 patients with AD longitudinally (intervals ranging from 12 to 40 months). AD patients were divided into a slowly-progressive group (S, 10 patients) and a rapidly-progressive group (R, 7 patients) on the basis of progression rates of symptoms. The perfusion ratio (%) (PR), defined as the activity density in regions of interest normalized to the mean activity density in unaffected regions (cerebellum, primary visual and sensory-motor cortex), was used as a measure of relative regional cerebral blood flow by SPECT. Hasegawa's dementia score (HDS) in both the first and last studies significantly correlated with PR of the temporoparietal lobe, but not PR of the frontal lobe. The PR of the frontal lobe in the first study was significantly decreased in R-group patients compared to S-group patients. However, there was no difference in PR of the temporoparietal lobe between the S and R groups. Though the change in PR (PR (last study-first study)/duration) in the frontal lobe was significantly less in R-group than in S-group patients, there was no difference in the change in PR in the temporoparietal lobe. These results suggest that the degree of intellectual impairment is related to the function of the temporoparietal lobe, that progression is related to function of the frontal lobe, and that frontal hypoperfusion on SPECT may predict relatively rapid intellectual deterioration.
Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 12/1995; 32(11):728-35.
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ABSTRACT: Several studies have shown that the symptomatology and the neuropathological and neurochemical changes of early-onset Alzheimer's disease (EAD) differ from those of late-onset Alzheimer's disease (LAD). The aim of the present study is to examine differences in SPECT and MRI findings between EAD and LAD. Cerebral blood flow and patterns on SPECT, and deep white matter lesions and cerebral atrophy on MRI in 17 patients with EAD were compared with 30 patients with LAD without cerebrovascular risk factors. Temporoparietal activity ratio, divided by cerebellum, on SPECT imaging in patients with EAD was significantly lower than in patients with LAD. In a qualitative assessment of perfusion patterns, bilateral temporoparietal hypoperfusion, which is typical in AD, was seen more frequently in patients with EAD than in those with LAD. Among white matter changes in MRI, the score of white matter hyperintensity was significantly higher in LAD than in EAD patients. However, there was no significant difference between periventricular hyperintensity scores. Though ventricular enlargement did not differ significantly in EAD and LAD, cortical atrophy scores in LAD were significantly higher than in EAD. Cortical atrophy scores were significantly higher in patients with atypical perfusion patterns on SPECT, (e.g. global hypoperfusion in addition to temporoparietal change), than in patients with typical perfusion pattern. These results indicate that functional and morphological imagings in LAD differ with those in EAD, probably due to less-prominent neuropathological degeneration combined with age-related alterations.
Rinsho shinkeigaku = Clinical neurology 11/1995; 35(10):1104-9.
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ABSTRACT: A new method for differential diagnosis of Alzheimer-type dementia (AD) and vascular dementia (VD) based on neuroimaging studies was developed by Hayashi's quantification theory II. Fifty-five patients with AD and 36 patients with VD underwent both SPECT and MRI studies. Both images in each subject were scored according to the extent of hypoperfusion in areas including frontal and temporoparietal regions and the severity of deep white matter lesions and medial temporal lobe atrophy. The scores of AD and VD patients were significantly different, and this difference was considered to contribute most to the differential diagnosis of AD and VD. The weight of each score of SPECT and MRI items was computed, and the sum of the weights was calculated as a score for each subject to best distinguish AD from VD patients. This method was designed to simplify the calculation of the sample scores, and the sum of the weights was established so that a positive score (0 < or =) indicated the probability of AD, while a negative score (< 0) indicated the probability of VD. The correct diagnosis rate was 91% (50/55) for AD and 89% (32/36) for VD, for an overall discrimination of 90%. The present method seemed to be practically useful in the differential diagnosis of AD and VD.
Nō to shinkei = Brain and nerve 08/1995; 47(7):665-70.
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ABSTRACT: Diffusion-weighted magnetic resonance imaging (DWI) was carried out on a patient with Binswanger's disease suffering from acute cerebral infarction. Though an acute infarcted lesion was demonstrated as a high signal area on the T2-weighted image, it was impossible to determine whether it was acute or chronic because of extensive deep white matter lesions (periventricular hyperintensity and white matter hyperintensity lesions). However, only the acute infarcted lesion was detected on DWI which showed it as a high signal area, suggesting reduced molecular diffusion of water. The apparent diffusion coefficient (ADC), a physiological parameter that characterizes the self-diffusion on water in tissue, was lower in the acute lesion and higher in the chronic lesion. DWI can differentiate acute from chronic infarcts, which is not possible by conventional CT and MRI.
Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 08/1995; 32(7):511-5.
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ABSTRACT: We sought to identify a marker for Alzheimer's disease (AD) for antemortem diagnosis. To determine whether the detection of reduced blood flow in the parietotemporal cortex, shown by single photon emission CT (SPECT), and of medial temporal lobe atrophy, shown by magnetic resonance imaging (MRI), would be useful in diagnosis, we studied 38 patients with AD diagnosed by the NINCDS-ADRDA criteria and 26 healthy elderly controls. Parietotemporal hypoperfusion was qualitatively assessed by physicians who were unaware of the clinical diagnosis, and the severity of medial temporal lobe atrophy was quantitated by planimetric and linear measurements. Although an accurate diagnosis of AD was made in 80% or more of the patients by SPECT or MRI studies alone, the combination of SPECT and MRI gave a higher diagnostic accuracy, with a sensitivity of 95% and a specificity of 92%. Since regional functional or structural changes were detected in 92% of early or mild patients, including possible AD, the combination of SPECT and MRI studies were useful in the early diagnosis of AD. Findings suggest that a functional abnormality in the parietotemporal lobe and an atrophic change in the medial temporal lobe are characteristic of AD, and that SPECT and MIR regional changes may be useful as antemortem diagnostic markers.
Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 10/1994; 31(9):683-9.
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ABSTRACT: MRI of 31 patients with dementia of the Alzheimer type (DAT) (mean age 74.7 years) were studied to detect characteristic findings, and compared with those of 24 normal elderly controls (mean age 74.1 years). Atrophy was quantitated by planimetric and linear measurements, and periventricular and deep white matter signal abnormalities were assessed by subjective ratings. Although we observed significant differences between the DAT patients and controls, there was overlap in each of the measurements. Of these, the ratio of the temporal horn area and the pattern of linear measurements (the width of the temporal horn body--the medial temporal lobe width--the interuncal distance) best distinguished the DAT patients from controls. Twenty-five patients (81%) had a ratio of the temporal horn area larger than the value of the mean + 2SD of the controls. AV-shaped pattern, in which the medial temporal lobe width was smaller than the other two values, was demonstrated in 84% of the patients and only 8% of the controls. Although signal abnormalities were not useful for diagnostic purposes, periventricular hyperintensities were more commonly seen in the DAT patients than in the controls, and correlated with cognitive function. MRI studies suggest that the assessment of medial temporal lobe atrophy is useful in the diagnosis of DAT, and periventricular hyperintensity may be related in some way to the disease process.
Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 06/1994; 31(5):388-95.
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Nippon rinsho. Japanese journal of clinical medicine 12/1993; 51 Suppl:783-7.
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ABSTRACT: In order to clarify the relationship between dementia and osteoporosis, bone mineral metabolism was studied in elderly female patients with dementia. We measured bone mineral densities of the vertebral body and the femoral neck using DEXA, and evaluated Ca-related factors in 22 patients with dementia of the Alzheimer type (DAT), 23 patients with vascular dementia (VD), and 22 age-matched controls (C). Activity of daily living was significantly poorer in VD patients than controls, but no difference was shown between DAT and C groups. Bone mineral density values of the vertebral body and the femoral neck were significantly decreased in both DAT and VD groups when compared to C group. DAT patients showed significant decreases in serum Ca and Ca2+ ion, increase in serum parathyroid hormone, and decrease in serum 1,25-dihydroxyvitamin D, a tendency towards decrease in serum calcitonin, and a tendency towards increase in urinary Ca. However, VD patients showed only significant increase in urinary Ca and a tendency towards decrease in serum 1,2-dihydroxyvitamin D, without showing other changes of Ca-regulating hormones. These results suggest that patients with dementia are more often associated with osteoporosis, and that in DAT several abnormalities of Ca-regulating factors play an important role in the development of osteoporosis, while in VD limited physical activities contribute to bone mineral loss.
Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 11/1993; 30(10):857-63.
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ABSTRACT: We report a case of Binswanger-type dementia demonstrated bilateral temporoparietal hypoperfusion in SPECT with 123I-IMP. The perfusion pattern in the present case was different from those previously obtained in SPECT or PET studies of patients with Binswanger-type dementia, and was similar to regional abnormalities in patients with Alzheimer-type dementia. Temporoparietal hypoperfusion in this case is likely to be mediated by neuronal mechanisms via projection fibers as a result of the deep white matter lesions in the temporoparietal area. A decreased perfusion or metabolism in the temporoparietal area is considered to be a characteristic in patients with Alzheimer-type dementia, however, we should keep in mind that other cerebral disorders may also show a similar perfusion pattern.
Kaku igaku. The Japanese journal of nuclear medicine 05/1993; 30(4):429-35.
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ABSTRACT: The relationships between blood flow in the cerebrum and the cerebellum was investigated in 21 normal subjects and 21 patients with dementia of the Alzheimer type (DAT). In normal subjects, only asymmetry in the frontal cortical blood flow was significantly correlated with asymmetry in the contralateral cerebellar blood flow. However, a significant correlation between asymmetry in the cerebral cortical blood flow in many areas and the blood flow in the contralateral cerebellum in DAT patients was observed. These results suggest the existence of a functional relationship between the cerebrum and the cerebellum in both normal and DAT groups, mediated by neuronal mechanisms through crossed fiber pathways. However, there are regional differences in the cerebrocerebellar relationship in normal resting and pathological states.
Annals of Nuclear Medicine 03/1993; 7(1):45-50. · 1.50 Impact Factor
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ABSTRACT: To determine whether the detection of parietotemporal functional abnormalities as demonstrated by single photon emission computed tomography (SPECT) can be employed as a diagnostic marker for Alzheimer's disease (AD), we studied 219 patients with neurologic disorders including 56 with AD and 25 healthy controls. The diagnostic sensitivity (parietotemporal hypoperfusion present in AD patients) was 82%, and the specificity (parietotemporal hypoperfusion absent in non-AD patients and controls) was 89%. These results suggest that SPECT imaging provides an accurate and sensitive diagnostic test for AD.
Gerontology 02/1993; 39(5):260-6. · 2.78 Impact Factor
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ABSTRACT: We conducted investigation to determine whether early- and late-onset Alzheimer's disease differ pathophysiologically. Five patients with the early-onset (65 years and under) of the disease and 11 with the late-onset (65 years and over) of the disease were studied by single photon emission CT (SPECT) with N-isopropyl-p-[123I]iodoamphetamine (IMP). Circumferential profile analysis (CPA) was performed to examine differences in the predominant hypoperfusion in the temporoparietal lobe, which is considered to be functionally damaged the most in Alzheimer's disease. The Xm values, calculated from gradients between the motor sensory or occipital cortices and temporoparietal cortex in the circumferential profile curve, were compared in both groups. The Xm values for the patients with early- and late-onset Alzheimer's disease were 6.81 +/- 2.10 (count/degree) and 3.28 +/- 1.58, respectively, the difference being significant. Our results suggest that functional abnormalities in the temporoparietal area severer in early- than late-onset Alzheimer's disease and that the application of CPA to IMP SPECT is useful to elucidate the pathophysiological difference between each of the disease.
Kaku igaku. The Japanese journal of nuclear medicine 11/1992; 29(10):1223-6.
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ABSTRACT: Regional cerebral blood flow was studied using single photon emission CT (SPECT) with 123I-IMP to elucidate the pathophysiology of amnesia. Four patients with amnestic syndrome diagnosed by DSM-III-R criteria were investigated. SPECT images demonstrated definite hypoperfusion of the temporoparietal lobe and relative sparing of motor-sensory and occipital cortices in two out of four patients. Since these abnormalities of regional cerebral blood flow have been considered to be characteristic findings in dementia of the Alzheimer type, two patients with temporoparietal hypoperfusion are suggested to manifest the early stage of dementia of the Alzheimer type. Our observations suggest that 123I-IMP SPECT is an useful modality in the diagnosis of the early stage of dementia of the Alzheimer type, especially in patients with only memory impairment.
Kaku igaku. The Japanese journal of nuclear medicine 07/1992; 29(6):691-4.
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ABSTRACT: To determine the diagnostic accuracy of single photon emission computed tomography (SPECT) with 123I-IMP in Alzheimer-type dementia (ATD), we studied 46 ATD patients and 23 healthy controls. The patients fulfilled the NINCDS-ADRDA criteria for probable or definite ATD and were classified as having mild, moderate, and severe ATD by neuropsychological examinations. To assess regional cerebral blood flow, we performed qualitative SPECT image analysis without any knowledge of the subject's clinical classification. The image was regarded as abnormal if cerebral blood flow was reduced in the unilateral or bilateral temporoparietal association areas, with or without any reduction of flow in other brain regions. The diagnostic sensitivity (abnormal image/patient) of 123I-IMP SPECT in mild, moderate, and severe ATD was 67%, 86%, and 92%, respectively. The specificity (normal image/control) was 91%, because an abnormal image was found in only 2/23 healthy controls. Eight ATD patients without reduced temporoparietal perfusion showed normal perfusion or frontal hypoperfusion. These results suggest that 123I-IMP SPECT may provide an accurate and sensitive diagnostic marker for ATD. The detection of these characteristic marker for ATD. The detection of these characteristic abnormalities of cerebral perfusion could well be applied to the clinical diagnosis of ATD.
Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 07/1992; 29(6):463-8.
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ABSTRACT: The author investigated factors leading to intellectual impairment in patients with multiple lacunar infarctions. The subjects consisted of 40 patients with multi-infarct dementia (MID) and 17 nondemented patients with multiple infarctions (MI) who showed multiple lacunar infarctions in the deep penetrating arterial territory on CT. MID patients showed more marked and extensive periventricular lucency (PVL), a higher degree of ventricular index (VI) measured on CT, and were of a higher age, and had poorer activity of daily living (ADL) compared with MI patients. There were significant correlations between the PVL score, VI, ADL score, age and Hasegawa's dementia rating score (HDS). However, no significant differences in sex, site of infarct, and the count of low density areas reflected lacunar infarction on CT, and vascular risk factors were shown between MID and MI patients. Multiple regression analysis demonstrated that the PVL score and VI showed the highest partial correlations for HDS, and that the ADL score and age were also independently contributing factors. Our results suggest that deep white matter lesions observed as PVL on CT and ventricular enlargement were the most important factors contributing to intellectual impairment in patients with multiple lacunar infarcts, and that physical factors such as ADL and age can be considered to be related to the development of dementia.
Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 05/1992; 29(4):298-304.
