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H Hanyu

Publications and source records attributed to H Hanyu.

52 records · Page 3Linked to original sources
PubMed1992

[Cerebral hemodynamic difference between early- and late-onset Alzheimer's disease by circumferential profile analysis with 123I-IMP brain SPECT].

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.

Aged↗
PubMed1992

[123I-IMP SPECT study on patients with amnestic syndrome].

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.

Aged↗
PubMed1991

[Crossed cerebellar atrophy following cerebrovascular lesions].

A neuroradiological study of crossed cerebellar atrophy (CCA) was performed using X-ray CT in 103 patients suffering from unilateral supratentorial cerebrovascular diseases. CCA was demonstrated in 9 (8.7%) of 103 patients. No difference between the occurrence of CCA in cerebral hemorrhage and that in cerebral infarction was found. CCA was seen in the chronic stage of cerebrovascular disease more than 3 years since stroke occurrence, and was found to be present more frequently and to a greater extent 7 years later. No correlation between the site of bleeding and the occurrence of CCA was found. Trans-synaptic degeneration of the corticopontocerebellar tract was considered in CCA following putaminal and combined hemorrhage involving an internal capsule lesion. However, in thalamic hemorrhage, retrograde degeneration within the cerebellorubrothalamic tract was presumed. CCA following cerebral infarction was seen in patients with massive lesions in the territory of the middle cerebral artery. Multivariate analysis showed that lesions of the parietal and frontal lobes appeared to greatly contribute to the development of CCA. As the degeneration and atrophy in the thalamus on the side of the lesion appeared early and frequently, it was suggested that retrograde degeneration of the cerebellorubrothalamic tract participated, in addition to anterograde corticopontocerebellar tract degeneration, in CCA following middle cerebral artery infarction. It is likely that CCA is caused by both transsynaptic degeneration of the corticopontocerebellar tract and the cerebellorubrothalamic tract.

Aged↗
PubMed1991

[Decreased cerebral blood flow in remote areas in deep-seated cerebrovascular lesions].

Recent positron or single photon emission computed tomographic studies have demonstrated that the impairment of regional hemodynamics or metabolism in cerebrovascular disease is not limited to the focal lesion, but also involves more remote areas. The present study evaluated cerebral blood flow in areas remote from the primary lesion in patients with subcortical cerebrovascular disease, and assessed correlations with the clinical features. Twenty patients aged 61-89 (mean, 74.7 +/- 6.7 years) were divided into the L group (lacunar infarction in deep penetrating arterial territory, n = 7), the NL group (non-lacunar subcortical infarction caused by main trunk occlusion or severe stenosis, n = 6), and the H group (putaminal or thalamic hemorrhage, n = 7). Ipsilateral cortical and contralateral cerebellar blood flow were assessed using single photon emission computed tomography with 123I-IMP. Although only some patients of the L group showed a mild reduction of ipsilateral cortical blood flow, most of the patients in the NL and H groups showed a moderate or severe flow reduction. The cortical blood flow reduction was suggested to be caused by several mechanisms, including brain edema, a decreased perfusion pressure associated with disease of large arteries, partial cortical neuronal damage, and deactivation. The degree of the flow reduction was considered to depend on the relative contribution of each of these factors. Contralateral cerebellar blood flow reduction, i.e., crossed cerebellar diaschisis, was observed more frequently and prominently in the NL and H groups than in the L group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Effects of cerebral cortical lesions on the ipsilateral thalamus].

An injury to the central nervous system causes a focal logical disturbance, and further may affect the blood flow, metabolism, and function of other brain regions. Recent studies using PET or SPECT have demonstrated that impairment of regional hemodynamics or metabolism in cerebrovascular disease involves not only the site of the lesion itself but also more remote areas. Although depression of the metabolism of the ipsilateral thalamus in patients with cerebral cortical lesions has been shown by PET study, the pathophysiological implications of this remain unclear. The functional and morphological effects of cortical infarcts on the ipsilateral thalamus were studied by assessment of cerebral blood flow using 123I-IMP SPECT and by determining atrophic changes on CT or MRI. Nine out of 17 patients with cortical infarcts showed hypoperfusion of the ipsilateral thalamus, especially patients with larger infarcts involving the frontal or parietal cortex. Thalamic hypoperfusion persisted from early after the insult to several months or even years later. In addition, atrophy of the ipsilateral thalamus was not uncommon following larger cortical infarcts. This tended to be evident about 1 year after the infarct and progressed over several years. Furthermore, atrophic changes in the thalamus was often demonstrated in such patients as hypoperfusion in the later stages. Thus, cortical lesions had functional and morphological effects on the ipsilateral thalamus ranging from early hypoperfusion to later irreversible atrophic changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Study of cerebral circulation and cerebrospinal fluid dynamics in a patient with agenesis of the corpus callosum using 123I-IMP SPECT and cine-mode MRI].

A right-handed, 77-year-old man, complaining of dizziness, was diagnosed as agenesis of the corpus callosum (ACC) by MRI, which demonstrated a complete defect of the corpus callosum (CC) with symmetrical enlargement of the posterior horns of the bilateral ventricles (colpocephy) and focal hypo-plasticity of the frontal lobes. Neurological examination revealed only mild impairment of mental function and poor transfer of tactile form-board learning from the right hand to the left hand. As to the cerebral circulation detected by 123I-IMP SPECT, isotope distribution corresponded to the MRI brain images, though the defects were clearly seen on the medial surfaces of the bilateral frontal lobes, so interhemispheric fissure seemed to be opened widely. IV-DSA revealed hypo-vascularity in the anterior territory of the anterior cerebral arteries. These findings suggested that this localized defect was due to hypo-vascularity and focal hypo-plasticity of the frontal lobes. On the other hand, cine-mode MRI findings that no signal-void phenomenon was found between the third ventricle and the longitudinal fissure indicated no shunt in cerebrospinal fluid.

Aged↗
PubMed1991

[The functional relationship between the cerebral cortex and deep brain areas in normal individuals].

Recent PET or SPECT studies have demonstrated a reduction of blood flow and metabolism in the cortex ipsilateral to a deep-seated lesion, and in the thalamus and/or basal ganglia ipsilateral to a cortical lesion. A close relationship between the cerebral cortex and deep areas of the brain has been shown in pathological conditions, presumably because of functional interconnections between the cortex and deeper area. The present study was designed to investigate the relationship of cerebral blood flow in the cerebral cortex to that in the deep gray matter including the basal ganglia and the thalamus in normal subjects. Twenty-two healthy subjects were studied using SPECT with N-isopropyl-p[123I]iodoamphetamine while in a resting state. The asymmetry index (AI) of blood flow in both the cerebral cortex and deep gray matter was calculated as follows; AI = (R-L)/(R+L)/200 (%) (R: right side, L: left side). The AI in deep gray matter was significantly correlated with the AI values in the upper frontal cortex (r = 0.54, p less than 0.01), and parietal cortex (r = 0.58, p less than 0.01), as well as the mean cortical hemispheric AI (r = 0.48, p less than 0.05). Our results suggest the existence of a functional relationship between the cerebral cortex and deep areas not only in pathological conditions but also in the resting state in normal subjects. This functional relationship is likely to be mediated by neuronal mechanisms through the projectional fiber connections between the cortex and the deep gray matter.

Adult↗
PubMed1991

[Functional relationships between the cerebrum and cerebellum or the cerebral cortex and deep gray matter in normal subjects and patients with Alzheimer's type dementia].

Since the various parts of the central nervous system are functionally interconnected, functional relationships between one region and another would be expected to be present. We investigated whether functional relationships between the cerebrum and cerebellum or between the cerebral cortex and deep gray matter exist in normal subjects and patients with Alzheimer's type dementia (AD), using the indicator of asymmetry in cerebral blood flow. Eighteen normal subjects (average age: 72.6 +/- 11.4 years) and 21 patients with AD (average age: 75.5 +/- 8.1 years) were studied in the resting state using SPECT with 123I-IMP. The asymmetry index (AI) of blood flow for matched left-right regions of interest was calculated as follows: AI = (R-L)/(R + L)/200(%) (R: right side, L: left side). For both the normal and AD groups, we found a negative correlation between AI in the cerebrum and AI in the cerebellum. The AIs of widespread cortical subregions, except the occipital cortex, were significantly correlated with AI in the cerebellum in the AD group. On the other hand, the only significant correlation found in normal subjects was between the AIs of the frontal cortex and cerebellum. A positive correlation between the AIs in the cerebral cortex and deep gray matter was observed in both the normal and AD groups. Though only the upper frontal and parietal cortices showed significant correlations with the deep gray matter in normal subjects, more extensive cortical subregions showed significant correlations in AD patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Functional relationship between the cerebrum and cerebellum in normal subjects].

To determine whether a functional relationship between the cerebrum and cerebellum exists in normal subjects, the correlation between asymmetry in cerebral blood flow and asymmetry in cerebellar blood flow was investigated. Twenty-one healthy right-handed subjects were studied using SPECT with N-isopropyl-p-(123I)iodoamphetamine while in a resting state. The asymmetry index (AI) for both the cerebral and cerebellar hemisphere was calculated as follows. AI = R - L/R + L/200 (%) (R: right side, L: left side). A negative correlation was found between AI in the cerebellum and AI in cerebrum. Especially, AI in cerebellar hemisphere was significantly correlated with AIs in the upper frontal cortex (r = -0.58, p less than 0.01), middle frontal cortex (r = -0.55, p less than 0.02), lower frontal cortex (r = -0.49, p less than 0.05), and mean cerebral hemisphere (r = -0.52, p less than 0.02). These results suggest the existence of a functional relationship between the cerebral hemisphere and the contralateral cerebellar hemisphere in the resting state of normal subjects. We strongly suspect that the frontal cortex exert an influence on the function in the contralateral cerebellum, probably due to a transneuronal mechanism, mainly through the corticopontocerebellar pathway.

Adult↗
PubMed1990

[Wallenberg's syndrome caused by a brain tumor--a case report and literature review].

we report a patient with Wallenberg's syndrome caused by glioma of the lateral medulla oblongata, and review the literature for Wallenberg's syndrome associated with neoplastic disease. A 46-year-old man was admitted because of progressive dysphagia and vertigo. Neurological examination revealed atypical symptoms and signs of Wallenberg's syndrome on the right side, hypalgesia on the second and third divisions of the left trigeminal nerve, paresis of the right palate and uvula, and ataxia of the right extremities. Although CT showed no abnormality in the posterior fossa, MRI demonstrated a mass with abnormal signal intensities in the right dorsolateral portion of the medulla. Biopsy specimens showed astrocytoma (grade III). Based on the present case and a review of 10 previously reported cases of Wallenberg's syndrome caused by neoplastic disease, the clinical features of this syndrome are characterized by gradual development and steady progression of symptoms, non-classical or atypical symptomatology, numerous additional symptoms and signs depending on the site and size of tumors, and poor prognosis.

Brain Neoplasms↗
PubMed1990

[A comparison study of SPECT and MRI in remote effects of chronic cerebrovascular disease].

A comparison study of SPECT and MRI was performed to investigate remote effects in 10 patients with chronic cerebrovascular disease. Hypoperfusion in the cerebellar hemisphere contralateral to supratentorial lesions, the overlying cerebral cortex ipsilateral to subcortical lesions, the thalamus ipsilateral to cortical lesions, and the visual cortex distant to optic radiation lesions was demonstrated using SPECT with 123I-IMP. Although hypoperfusion in these remote areas was considered to be related to irreversible degenerative processes in the chronic phase, MR images did not reveal any abnormalities.

Aged↗
PubMed1990

[Remote effects in cerebral infarction--123I-IMP SPECT study].

We studied the remote effects in 29 patients with middle cerebral artery territory infarction by using single photon emission computed tomography (SPECT) with N-isopropyl-p-[123I]iodoamphetamine. SPECT demonstrated a reduction in blood flow in the cerebellar hemisphere contralateral to the cerebral infarct, the cortex ipsilateral to the subcortical infarct, the visual cortex distal to the optic radiation lesion, and the thalamus ipsilateral to the cortical infarct. In addition to transient neuronal depression identified with diaschisis, our results indicated that persistent phenomena were apparently involved in these remote effects. The degenerative processes might be related to irreversible effects in remote areas. Clinical symptoms corresponding to the areas of hypoperfusion remote from infarcted lesions were not necessarily present.

Aged↗
PubMed1990

[Asymmetry of cerebral blood flow in patients with senile dementia of Alzheimer type by SPECT using I-123 IMP].

Regional cerebral blood flow (rCBF) was determined by single photon emission CT (SPECT) with N-isopropyl-p-[123I]iodoamphetamine in 22 patients with clinically diagnosed senile dementia of Alzheimer type (SDAT) and in 18 age matched controls. We calculated asymmetry indices (AIs) of rCBF for matched right-left regions of interest. rCBF of parietal lobe in SDAT patients was significantly most laterally asymmetrical, but the least in occipital lobe. Lateral asymmetry of rCBF in SDAT patients correlated with asymmetry of language and visuospatial functions; decreased rCBF in the left parietal lobe was associated with language dysfunction, and that in the right parietal lobe, with visuospatial dysfunction. Furthermore cerebellar AIs correlated negatively with those of the cerebral hemisphere and lower frontal region in SDAT patients. The results demonstrate that rCBF measurement by 123I-IMP SPECT is useful to detect lateral asymmetry in reduction of rCBF in SDAT.

Aged↗
PubMedDate not supplied

[Cardiac function in elderly patients with dementia].

Evaluation of cardiac function is very important in elderly patients because it is closely related to the prognosis. Appropriate evaluation is especially important to treat and prevent the progression of dementia since its pathology differs greatly depending on type. In the present study, we evaluated the cardiac function of patients with senile dementia using echocardiography. Included in the present study were 11 patients with Binswanger-type dementia (BD), 12 with cerebrovascular dementia (VD) of other types, 16 with senile dementia of Alzheimer-type (SDAT) and 15 controls. Left ventricular function was assessed by Mode M based on left ventricular end-diastolic dimension (LVDd), left ventricular end-systolic dimension (LVDs), left ventricular dimension shortening (FS), left ventricular ejection fraction (EF) and cardiac output (CO). LVDd was significantly larger in the BD group than in the control, and LVDs was also significantly larger in the BD group than in the three other groups. FS was significantly decreased in the BD group compared to the SDAT and controls. FS was also significantly decreased in the VD group compared to the control. EF was significantly decreased in the BD group compared to the three other groups, and it was also significantly decreased in the VD group compared to the controls. There was no significant inter-group difference in SV or CO. FS and EF were found to be decreased in patients with cerebrovascular dementia, especially BD, indicating the presence of latent left ventricular hypofunction in these patients. This finding is important in predicting the prognosis of patients and conducting treatment and prevention.

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