PubMed Health⌕ Search

Biomedical subjects

H Nabatame

Publications and source records attributed to H Nabatame.

At least 19 recordsLinked to original sources
PubMed2001

[Clock drawing in dementia: its reliability and relation to the neuropsychological measures].

To examine the reliability and validity of clock drawing (CD) for evaluating dementia patients in Japan, we investigated the CD performance and its relation to several neuropsychological tests in 150 demented patients including 105 patients with Alzheimer disease and 30 age- and education-matched non-demented subjects (16 patients with mild cognitive impairment and 14 normals). Patients were also evaluated using the Mini-mental State Exam (MMSE), Wechsler Memory Scale (WMS), Kohs Block Design, and word fluency. CD was scored using the Shulman method. CD scores showed a high interrater reliability (r = 0.97). CD by non-demented subjects was essentially normal. As a screening test for Alzheimer disease (AD, mean MMSE = 18.0), CD had a sensitivity of 57.1% and a specificity of 96.7%. However, four of eight AD patients who showed normal MMSE score (> or = 24) drew abnormal clocks. CD scores in dementia were significantly correlated with performance on the Block Design (r = 0.68), MMSE (r = 0.56), and the Mental Control subtest in the WMS (r = 0.58). Stepwise regression analysis revealed that performance on the MMSE and the Block Design explain 53.8% of the variance in the CD scores. These findings indicate that low CD score by the Shulman method may be reflective of a constructional disability and general severity of dementia. CD is not so sensitive as the result of the original report when the patient group includes milder cases of AD. CD is, however, an efficient screening test for detecting and following the patients with dementia, especially combined with the MMSE.

Aged↗
PubMed2000

Atrophy of the corpus callosum associated with a decrease in cortical benzodiazepine receptor in large cerebral arterial occlusive diseases.

OBJECTIVES: It remains controversial whether selective neuronal ischaemic change develops in patients with occlusion of the large cerebral arteries. Previous studies have shown atrophy of the corpus callosum with reduced cortical oxygen metabolism in large cerebral arterial occlusive diseases, which might be indirect evidence of loss of the neurons in cortical layer 3. Recent studies of patients with ischaemic cerebrovascular diseases have demonstrated reduced central benzodiazepine receptor (BZR) binding in the normal appearing cortical areas, which might be more direct evidence of changes of the neurons. Although pathophysiology of the decreased BZR is unclear, a decrease in the cortical BZR binding with neuronal loss would cause atrophy of the corpus callosum. The purpose of this study was to determine whether atrophy of the corpus callosum is associated with a decrease in cortical BZR binding in large cerebral arterial occlusive diseases. METHODS: Seven patients with occlusive diseases of the middle cerebral or internal carotid artery and only minor subcortical infarctions were studied. Single photon emission tomographic images of (123)I labelled iomazenil (IMZ) obtained 180 minutes after injection were analysed for BZR binding. The midsagittal corpus callosum area/skull area ratio (on T1 weighted magnetic resonance images) was compared with the cerebral IMZ uptake/cerebellar IMZ uptake ratio. RESULTS: Compared with 23 age and sex matched control subjects, the patients had significantly decreased callosal area/skull area ratio. The degree of corpus callosum atrophy was significantly and strongly (rho=0.99, p<0.02) correlated with that of the decreases in the mean cerebral cortical IMZ uptake ratio. CONCLUSION: Corpus callosum atrophy may occur in association with a decrease in cortical BZR binding in large cerebral arterial occlusive diseases. Corpus callosum atrophy with decreased cortical BZR binding might reflect cortical neuronal damage in large cerebral arterial occlusive diseases.

Aged↗
PubMed1999

[Cerebral hemodynamics and risk for recurrent stroke in symptomatic internal carotid artery occlusion].

PURPOSE: In internal carotid artery occlusion, patients with inadequate blood supply relative to metabolic demand (misery perfusion) may be at increased risk for cerebral ischemia. This study investigated whether patients demonstrating misery perfusion on positron emission tomography (PET) have a high risk of subsequent stroke in symptomatic internal carotid artery occlusion. METHODS: We prospectively evaluated the relationship between the regional hemodynamic status of cerebral circulation and the subsequent risk of stroke in 40 patients with symptomatic internal carotid artery occlusion who underwent PET. Patients were divided into two hemodynamic categories according to the mean hemispheric value of oxygen extraction fraction (OEF) in the hemisphere supplied by the artery with symptomatic disease: patients with increased OEF and those with normal OEF. All patients were followed with medical treatment until the recurrence of stroke or death for 3 years. RESULTS: The three-year incidence of ipsilateral ischemic strokes for patients with normal OEF and those with increased OEF were 1 of 34 and 3 of 6 patients, respectively. A significantly higher incidence of ipsilateral strokes was found in patients with increased OEF (Kaplan-Meier analysis and log-rank test; p < 0.001). Multivariate analysis with the Cox proportional hazards model demonstrated that increased OEF significantly increased stroke recurrence: the relative risk was 19.5 (95% CI, 2.0-188.6) for ipsilateral stroke. An increase in the absolute OEF value was a better predictor of recurrent ischemic stroke than an OEF asymmetry. CONCLUSION: These findings suggest that patients with symptomatic internal carotid artery occlusion and misery perfusion have a high risk for subsequent stroke. Thus, identification and optimal treatment of patients with misery perfusion may be essential in preventing stroke.

Aged↗
PubMed1999

Significance of increased oxygen extraction fraction in five-year prognosis of major cerebral arterial occlusive diseases.

UNLABELLED: In major cerebral arterial occlusive diseases, patients with increased oxygen extraction fraction (OEF), which is measured with PET, may be at increased risk for cerebral ischemia. However, the clinical significance of increased OEF remains unclear. This study investigated whether increased OEF is an independent predictor of 5-y risk of subsequent stroke. METHODS: We prospectively evaluated the relationship between the regional hemodynamic status of cerebral circulation and the subsequent risk of stroke in 40 patients with symptomatic internal carotid or middle cerebral arterial occlusive diseases who underwent PET. Patients were divided into two hemodynamic categories according to the mean hemispheric value of OEF-in the hemisphere supplied by the artery with symptomatic disease: one group with increased OEF and one with normal OEF. All patients were followed for 5 y with medical treatment until the recurrence of stroke or death. RESULTS: During 5 y, 11 total and 9 ipsilateral ischemic strokes occurred. The incidences of all ischemic strokes in patients with increased OEF and in those with normal OEF were 5 of 7 and 6 of 33 patients, respectively. There were 4 ipsilateral ischemic strokes in patients with increased OEF and 5 in those with normal OEF. Kaplan-Meier analysis revealed that the risks of all stroke and ipsilateral ischemic stroke in patients with increased OEF were significantly higher than in those with normal OEF (log-rank test; P<0.0002 and P<0.0018, respectively). Multivariate analysis with the Cox proportional hazards model showed that increased OEF significantly increased stroke recurrence: the relative risk was 7.2 (95% confidence interval [CI], 2.0-25.5; P<0.005) for all stroke and 6.4 (95% CI, 1.6-26.1; P<0.01) for ipsilateral stroke. An increase in the absolute OEF value was a better predictor of recurrent ischemic stroke than was OEF asymmetry. CONCLUSION: These findings suggest that an increased OEF is an independent predictor of 5-y risk of subsequent stroke. Identification of patients with increased OEF may have clinical significance in preventing recurrent stroke.

Adult↗
PubMed1997

Assessment of benzodiazepine receptors using iodine-123-labeled iomazenil single-photon emission computed tomography in patients with ischemic cerebrovascular disease. A comparison with PET study.

BACKGROUND AND PURPOSE: [123I]Iomazenil (IMZ) is a tracer used for single-photon emission computed tomography (SPECT) that has the characteristics of selectively binding to central benzodiazepine receptors (BZR) in the neuron membrane. To determine whether IMZ SPECT provides new information on assessing neuronal damage after ischemic insult to the brain, we compared IMZ SPECT images with the cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), and cerebral metabolic rate of glucose (CMRGlc) studied by position emission tomography in the chronic stage of ischemic stroke. METHODS: Five patients (male; mean age, 63.2 +/- 6.0 years) with ischemic cerebrovascular disease and 6 age- and sex-matched normal control subjects were studied. IMZ images obtained 180 minutes after injection were analyzed for BZR binding, and these images were compared with the CBF, CMRO2, and CMRGlc obtained by position emission tomography in the same perfusion areas both visually and quantitatively. RESULTS: In the visual analysis of data obtained from 4 patients with subcortical infarction, decreased IMZ accumulation was observed locally in the overlying normal-appearing cortices of the affected hemisphere, where extensive hypoperfusion and hypometabolism were seen on the images of CBF, CMRO2, and CMRGlc. The regional relative IMZ uptake (regional to cerebellar ratio) for all 5 patients was significantly correlated with the corresponding regional CMRO2 values (r = .45, P < .05). However, no significant correlation was found of the IMZ uptake with either the regional CBF or the regional CMRGlc. CONCLUSIONS: The use of IMZ SPECT provides new information on the neuronal alteration induced by chronic ischemic cerebrovascular disease.

Aged↗
PubMed1996

Evidence of misery perfusion and risk for recurrent stroke in major cerebral arterial occlusive diseases from PET.

OBJECTIVES: In major cerebral arterial occlusive diseases, patients with inadequate blood supply relative to metabolic demand (misery perfusion) may be at increased risk for cerebral ischaemia. This study investigated whether patients showing misery perfusion on PET have a high risk of recurrent ischaemic stroke. METHODS: The relation between the regional haemodynamic status of cerebral circulation and the subsequent risk of recurrent stroke was prospectively evaluated in 40 patients with symptomatic internal carotid or middle cerebral arterial occlusive diseases who underwent PET. Patients were divided into two haemodynamic categories according to the mean hemispheric value of oxygen extraction fraction in the hemisphere supplied by the artery with symptomatic disease: patients with normal oxygen extraction fraction and those with increased oxygen extraction fraction (misery perfusion). All patients were followed up for at least 12 months. RESULTS: The one year incidence of ipsilateral ischaemic strokes for patients with normal oxygen extraction fraction and those with increased oxygen extraction fraction were two of 33 and four of seven patients respectively. A significantly higher incidence of ipsilateral strokes was found in patients with increased oxygen extraction fraction (Fisher's exact test; P = 0.005). In patients with increased oxygen extraction fraction, three of four strokes were watershed infarctions and the location of the infarction corresponded with the area of increased oxygen extraction fraction. CONCLUSION: These findings contradict conclusions of a previous study and suggest that patients with major cerebral arterial occlusive diseases and misery perfusion have a high risk for recurrent ischaemic stroke.

Adult↗
PubMed1996

[Respiratory management after closure of a bronchial-fistula with an omental pedicled gastric flap].

A 56-year-old female, after closure of a bronchial-fistula with an omental pedicle gastric flap, underwent controlled ventilation for two weeks in order to stabilize the flap. We suspended the administration of vecuronium once a day and examined the plasma concentration of vecuronium when a twitch response appeared. During the two weeks of ventilation, plasma concentration of vecuronium was maintained at low doses by adjusting the daily dose of vecuronium infusion. However, the suspended period of vecuronium infusion was prolonged gradually and the patient care such as tracheal suction and position changing became restricted. In addition, we have to care for the infection and a mental injury.

Bronchial Fistula↗
PubMed1995

[The correlation of the thalamic lesions on MRI with cerebral cortical blood flow in patients with lacunar infarction].

We performed MRI and measured cerebral blood flow (CBF) using 123I-IMP SPECT microsphere model in twenty three right-handed patients with lacunar infarction. Twelve of 23 patients showed chronic deterioration of dysarthria and gait disturbance. The mental function of the patients was evaluated by the Mini-Mental State (MMS) examination. The area of high intensity on T2-weighted images was quantitatively analyzed in the cerebral white matter (WM), lenticular nucleus (LN) and thalamus (THA). The score of MMS was positively correlated with the local CBF in the bilateral frontal, parietal, temporal and occipital cortices (p < 0.05). Also, the area of high intensity in the left THA showed a significant negative correlation with local CBF of the bilateral frontal, parietal, temporal and occipital cortices (p < 0.001). The high intensity areas of the bilateral LN, right WM and right THA had a significant but weaker negative correlation with local CBF of some cortices. These findings suggest that thalamic lesions on the dominant side play an important role in the reduction of cortical blood flow and the deterioration of mental functions in patients with lacunar infarction.

Aged↗
PubMed1994

Hemichorea in hyperglycemia associated with increased blood flow in the contralateral striatum and thalamus.

We studied a patient with hyperglycemia who developed choreic involuntary movements in the right extremities using single photon emission computed tomography (SPECT) with 123I-N-isopropyl-p-iodoamphetamine. SPECT revealed an increased blood flow in the left striatum and thalamus. Through the control of blood glucose and the administration of haloperidol, the hemichorea was resolved, and the increased blood flow in the striatum and thalamus disappeared. These findings suggest that the increased blood flow, which probably indicates increased neuron activity in the striatum and thalamus, is an underlying pathophysiological state in hemichorea.

Aged↗
PubMed1993

Callosal atrophy parallels decreased cortical oxygen metabolism and neuropsychological impairment in Alzheimer's disease.

OBJECTIVE: To evaluate the relationship of corpus callosum atrophy to cerebral cortical oxygen metabolism and cognitive function in patients with Alzheimer's disease. DESIGN: Prospective clinicoradiologic correlation with magnetic resonance imaging and positron emission tomography. SETTING: A university hospital. PATIENTS, PARTICIPANTS: Ten right-handed male patients with Alzheimer's disease, aged 46 to 70 years (mean +/- SD 57 +/- 6 years), and 14 age- and sex-matched right-handed control subjects. MAIN OUTCOME MEASURES: The midsagittal corpus callosum areas (on T1-weighted magnetic resonance images), cerebral metabolic rate of oxygen (measured with positron emission tomography using the oxygen-15 steady-state technique), and the IQs of the Wechsler Adult Intelligence Scale. RESULTS: Compared with control subjects, the patients had significantly decreased callosal areas with a posterior predominance of the degree of atrophy. The area of anterior and posterior halves of the corpus callosum had a significant correlation with the value of oxygen metabolism in the frontal and parietotemporo-occipital association cortices, respectively. The total area of the corpus callosum was significantly related to the total and verbal IQs of the Wechsler Adult Intelligence Scale. CONCLUSION: Atrophy of corpus callosum reflects the severity and pattern of cortical damage associated with hypometabolism and cognitive impairment in Alzheimer's disease.

Aged↗
PubMed1993

Callosal atrophy with reduced cortical oxygen metabolism in carotid artery disease.

BACKGROUND AND PURPOSE: In cerebrovascular disease, brain atrophy may be a reflection of ischemic changes. Minor changes that are not detectable as infarction on computed tomography may result in atrophy with metabolic depression. We evaluated the relation between size of the corpus callosum and cerebral cortical oxygen metabolism in carotid artery disease. METHODS: We used magnetic resonance imaging and positron emission tomography to evaluate 13 right-handed male patients with transient ischemic attacks or minor strokes and unilateral internal carotid artery occlusive disease, two with stenosis and 11 with occlusion. Computed tomography showed only minor subcortical abnormalities in the affected hemisphere. Midsagittal corpus callosum areas on T1-weighted magnetic resonance images, white matter lesions on T2-weighted images, and the cerebral metabolic rate of oxygen measured by the oxygen-15 steady-state technique were analyzed. RESULTS: Compared with 13 age- and sex-matched control subjects showing the same degree of white matter areas of high intensity, the patients had significantly decreased callosal areas. The degree of corpus callosum atrophy was significantly correlated with the mean cortical oxygen metabolic rate. The same tendency was also found in five patients without infarcts on computed tomography. However, neither the callosal area nor the hemispheric metabolic rate was correlated with the extent of white matter lesions. CONCLUSIONS: These findings indicate that atrophy of the corpus callosum occurs in association with a decrease in cortical oxygen metabolism. Corpus callosum atrophy may be a useful morphological index that reflects the cerebral cortical metabolic state in carotid artery occlusive disease.

Aged↗
PubMed1992

MRI of syphilitic myelitis.

MR imaging was performed on a patient with syphilitic myelitis. T2-weighted images showed high intensity areas in the thoracic spinal cord. On T1-weighted images after gadolinium-DTPA injection, heterogeneous enhancement was observed in the superficial portion of the spinal cord. The intramedullary high intensity areas on T2-weighted images disappeared after antibiotic therapy.

Contrast Media↗
PubMed1992

Significance of low perfusion with increased oxygen extraction fraction in a case of internal carotid artery stenosis.

BACKGROUND AND PURPOSE: Decreased cerebral blood flow with an increased oxygen extraction fraction, the so-called misery perfusion syndrome, suggests a vulnerability to reduction in cerebral perfusion pressure and a tendency to develop cerebral infarction. It is uncertain, however, whether the infarct would occur in the brain region specifically exhibiting this condition. CASE DESCRIPTION: We report the case of a patient with right intracranial internal carotid artery stenosis who presented with mild left hemiparesis resulting from a right frontal watershed infarct. Positron emission tomography 2 months after the stroke showed decreased cerebral blood flow with an increased oxygen extraction fraction in noninfarcted areas of the affected hemisphere. Maximal changes were detected in the watershed area between the middle cerebral artery and the posterior cerebral artery. Three months later, while on antiplatelet therapy, he suffered a new infarct in the right temporo-occipital watershed area that had shown the highest oxygen extraction fraction value on the first positron emission tomographic study. One month after the recurrence of stroke, a second study showed that low perfusion with increased oxygen extraction fraction persisted in the affected hemisphere to a lesser degree than in the first study. CONCLUSIONS: This observation suggests that the area of low perfusion exhibiting the highest oxygen extraction fraction has the highest risk for infarction. Increased oxygen extraction fraction may be an important factor in the development of hemodynamic infarction.

Brain↗
PubMed1992

[Visual agnosia evolving to optic aphasia--a case study].

The underlying mechanism of visual agnosia and optic aphasia has not been fully elucidated, although a number of hypotheses have been proposed. Besides, the difference between these two conditions has been a matter of debate. We report here the result of neuropsychological evaluation in a case of associative visual agnosia evolving to optic aphasia. A 64-year-old right-handed patient was found to be disoriented and confused after undergoing the operation of gastrectomy. CT scan revealed a large infarction in the territory of left posterior cerebral artery. Since 3 weeks after onset, neuropsychological investigations were carried out during 5 months. He was alert and co-operative. Right homonymous hemianopia with macular sparing was noted, but his visual acuity was normal. There was neither a global deterioration of intellectual capacities nor aphasia. Most striking finding was his difficulty in identifying common objects and colours along with a profound alexia. Prosopagnosia was absent. Visual naming both for objects and line drawings was severely impaired. He was unable to describe or demonstrate the use of the objects which could not be named. Pointing to objects named by the examiner was also severely impaired. Although tactile naming was also impaired, both of auditory naming for environmental sounds and naming objects in response to verbal descriptions were preserved. While he was not able to copy the objects skillfully, matching of identical objects and matching objects to line drawings were normal. Clumsiness of coping was thought to be due to his constructional apraxia and visuomotor ataxia. Therefore, his deficit in visual domain was considered to be associative visual agnosia.(ABSTRACT TRUNCATED AT 250 WORDS)

Agnosia↗
PubMed1991

[Spinal epidural abscess as the cause of torticollis--diagnosis by magnetic resonance imaging].

Spinal epidural abscesses are rare, accounting for only 0.2-1.2 of every 10,000 hospital admissions. Because they often present with non-specific symptoms, they are frequently misdiagnosed. We present a case in which superconduction MRI was used to make the diagnosis and to follow the clinical course of a spinal epidural abscess. In December 1988, a 33-year-old male developed spiking fever and the sudden onset of torticollis. He had had a cerebral palsy from birth, with chronic tetraparesis and mental retardation. Isolation of staphylococcus aureus in urine and blood cultures confirmed the diagnosis of pyelonephritis and septicemia. A high fever persisted despite antibiotic therapy commenced immediately. A technetium 99 m scan showed a localized uptake of isotope in the cervical spine. An MRI examination performed in the following day under sedation showed a mass with the same signal intensity as muscle on T1-weighted images. It was located behind the vertebral bodies C1-Th1 compressing the spinal cord. In addition, a lesion with a decreased signal was also evident in the C5-C6 vertebral bodies. Because of torticollis, the patient was unable to keep his head still for a sufficient period of time, to obtain T2-weighted imaging. The MRI findings indicated the presence of a spinal epidural abscess and osteomyelitis. A second MRI done one month after admission showed a reduction in the size of the epidural mass, but further diminishing of the signal intensity of the vertebral lesion. One month later, the patient underwent the surgical removal of the pus and inflammatory soft tissue, and anterior fusion. The torticollis resolved following the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗
PubMed1989

[Left antero-medial thalamic infarction and symptoms of amnesia, aphasia, and dementia].

Three cases of left antero-medial thalamic infarction who showed amnesia, aphasia and dementia were studied comparatively in terms of clinical features and the MRI findings. Case 1 and Case 2, who showed transient amnesia and aphasia respectively, had a single lesion in the left antero-medial thalamus. Case 1 had a lesion in a more ventral part than Case 2, suggesting that Case 1 had a lesion of the bundles into the anterior and dorsomedial thalamic nuclei while Case 2 had a lesion of the ventrolateral thalamic nucleus. On the other hand, Case 3 who showed persistent dementia had multiple lesions in addition to the left antero-medial thalamic infarction. A review of the previous reports and investigations of the present cases suggest that a single ischemic lesion in the left antero-medial thalamus will cause amnesia and/or aphasic symptom while in cases with other multiple lesions it may cause persistent dementia.

Aged↗