-
[show abstract]
[hide abstract]
ABSTRACT: A 66-year-old right-handed man developed pure anarthria following pure word deafness. In addition to language disorders, his behavior gradually changed and finally included violence against his wife. Brain magnetic resonance imagings revealed atrophy of the left perisylvian area, which included the inferior half of the precentral gyrus and the upper portion of the superior temporal gyrus, consistent with frontotemporal dementia (FTD). It has been documented as either a disorder of expressive language or as an impaired understanding of word meaning. Unlike with pure anarthria, pure word deafness is not included in the clinical diagnostic current criteria for FTD. However, a large variety of language symptoms can appear in FTD according to the distribution of pathological changes in the frontotemporal cortices. This case suggests that pure word deafness could be a prodomal symptom of FTD.
European Journal of Neurology 05/2007; 14(4):473-5. · 3.69 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To study the ability of patients with semantic dementia to understand actions, in order to examine the contribution of semantic memory to action comprehension.
The ability to comprehend symbolic and instrumental actions was assessed in 6 patients with semantic dementia and 10 healthy controls. The patients were also given the imitation test of meaningful and meaningless actions.
In all patients with semantic dementia, comprehension of both symbolic and instrumental actions was defective. The comprehension of symbolic actions was more impaired than that of instrumental actions. Their ability to imitate other's actions was well preserved.
This study showed that comprehension of action was impaired in semantic dementia, suggesting that semantic memory has an important role in comprehension of human action.
Journal of neurology, neurosurgery, and psychiatry 01/2007; 77(12):1313-7. · 4.87 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The aim of this study was to identify relevant risk factors for occlusive lesions of the intracranial arteries in stroke-free population. The subjects of this study were 425 patients without a history of stroke or transient ischemic attack and without any abnormality on a neurological examination who consecutively visited a neurology clinic between January 1994 and June 2001 requesting medical evaluation for possible cerebrovascular diseases. Subjects included 245 men and 180 women ranging in age from 33 to 89 years (mean+/-SD=64.0+/-10.0 years). We performed cervical and intracranial magnetic resonance angiography (MRA) in all subjects. Using a validated rating scheme of MRA for occlusive lesions, we evaluated the degree of stenoses in the extracranial portion of the internal carotid artery (ICA) and the intracranial arteries including the intracranial portion of the ICA, middle cerebral artery (MCA) stem, intracranial portion of the vertebral artery (VA), and basilar artery (BA). More than 25% stenoses were regarded as significant lesions in this study. Multiple logistic regression analyses showed that significant and independent predictors for extracranial ICA lesions were age, hyperlipidemia, and ischemic heart disease (IHD), those for intracranial ICA lesions were age, hypertension, diabetes mellitus, and IHD, those for MCA lesions were age and hypertension, those for intracranial VA lesions were hyperlipidemia and IHD, and those for BA lesions were hypertension and diabetes mellitus. The present study suggested that atherosclerosis of the intracranial VA was related to hyperlipidemia and IHD as was the case for the extracranial carotid artery, whilst atherosclerosis of other sites of intracranial arteries was associated with hypertension and diabetes mellitus in stroke-free Japanese.
European Journal of Neurology 04/2005; 12(3):218-22. · 3.69 Impact Factor
-
European Neurology 02/2005; 54(2):123-4. · 1.81 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Progression of atherosclerosis at extracranial carotid and intracranial arteries in patients with ischemic heart disease (IHD) is not well defined. We carried out a 5-year longitudinal study with magnetic resonance angiography (MRA) of patients with IHD to assess the incidence of progression of atherosclerosis at extracranial carotid and intracranial arteries and to determine predictors of the progression. We previously performed carotid and intracranial MRA on 67 patients who had received selective coronary angiography for the clinical diagnosis of IHD. Of these 67 subjects, 41 patients gave informed consent to undergo MRA reexaminations to evaluate changes of extra- and intracranial arteries over a 5-year period. The degree of stenosis was divided into five grades depending on the narrowness of the arteries, i.e. normal, mild, moderate, severe and occluded. The average of follow-up period with MRA examination was 58.8 months. The progression of atherosclerosis, as defined as an increase of one grade of the stenosis rating, including both the exacerbation of pre-existing stenosis and the appearance of new stenotic lesions, were found in five patients (12.2%) for the cervical carotid artery and in only one patient (2.4%) for the intracranial artery. A multiple logistic regression analysis revealed that baseline carotid artery stenosis (P = 0.008), age (P = 0.047), and coronary events during the follow-up period (P = 0.048) were significant and independent predictors of progression of carotid atherosclerosis. In conclusion, our findings suggest that follow-up evaluation of the carotid artery is indicated for patients with IHD in whom carotid artery stenosis was detected on an initial examination. Further study is needed with larger numbers of patients to confirm these findings.
European Journal of Neurology 10/2003; 10(5):507-12. · 3.69 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We described a patient with bilateral striatal infarcts, in whom stereotyped and disinhibited behaviors were insidiously emerged over 2 years mimicking frontotemporal dementia (FTD). A positron emission tomography with 18-fluorodeoxy glucose showed a hypometabolism in the frontal lobes, basal ganglia, and thalami. The peculiar behavioral alterations remained unchanged for the following 7 years, suggesting that the disease is not degenerative but of vascular origin. A disruption of the fronto-subcortical circuits at the level of the striatum or the anterior thalamic peduncle is attributable to the FTD-like behavioral and cognitive syndrome.
European Journal of Neurology 08/2003; 10(4):457-60. · 3.69 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We report on a patient with pure transient global amnesia (TGA) whose magnetic resonance imaging (MRI) demonstrated a small region of increased signal intensity in the right hippocampus on diffusion-weighted imaging (DWI). DWI was sensitive and useful for evaluating the early stage of TGA and might help to explain the pathophysiology of TGA.
Neuroradiology 04/2002; 44(3):235-8. · 2.82 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Although the APOE epsilon4 allele is a well-known risk factor for developing AD, the impact of the epsilon4 allele on clinical manifestations in patients with AD is still controversial. One possible reason for this controversy is that previous studies did not consider the effect of patient age at symptom onset.
To investigate the possible impact of patient age at onset of AD on the effect of APOE genotype on regional cerebral glucose metabolism (rCMRglc).
The authors compared rCMRglc between probable AD patients (based on criteria of the National Institute of Neurologic Disease and Stroke/AD and Related Disorders Association) with APOE epsilon4/4 and APOE epsilon3/3 alleles in early-onset (< or =65 years old) and late-onset (>65 years old) groups. In each group, the patients with APOE epsilon4/4 and APOE epsilon3/3 alleles were comparable for age at onset, age at examination, sex, disease duration, education level, and severity of dementia.
In the early-onset group, the patients with the APOE epsilon4/4 genotype showed a significant decrease of rCMRglc in the medial temporal lobe and a significant increase of rCMRglc in the inferior parietal and posterior temporal cortices as compared with those patients with the APOE epsilon3/3 genotype. In the late-onset group, there were no significant differences in the rCMRglc pattern between the patients with APOE epsilon4/4 and APOE epsilon3/3 alleles.
The current findings indicate that the impact of the APOE epsilon4 genotype on cerebral glucose metabolism of patients with AD may be a function of age at symptom onset.
Neurology 03/2002; 58(5):743-50. · 8.31 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Although the APOE epsilon 4 allele increases the risk of developing AD, the effects of the epsilon 4 allele on brain atrophy in clinical AD patients are controversial.
To investigate a possible relationship between the genetic variants of APOE and brain atrophy in patients with AD.
Using MRI-based volumetry techniques, the authors compared the volumes of the hippocampal formation, amygdaloid complex, and whole brain in probable AD patients (based on criteria of the National Institute for Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association) with different APOE alleles. One group (n = 46) had the epsilon 3/3 allele, one group (n = 46) had the epsilon 3/4 allele, and one group (n = 46) had the epsilon 4/4 allele. The three groups were matched for age, sex, disease duration, education level, and severity of dementia represented by their score of the Mini-Mental State Examination. A possible difference in pattern of cognitive deficits with dose of the APOE epsilon 4 allele was also examined.
The normalized hippocampal volume was correlated with the number of APOE epsilon 4 alleles (r = -0.285, p = 0.0007). The amygdalar volume was also correlated with the number of APOE epsilon 4 alleles (r = -0.178, p = 0.037). The number of APOE epsilon 4 alleles was positively correlated with the whole-brain volume (r = 0.185, p = 0.030). It was also correlated with Wechsler Adult Intelligence Scale-Revised performance IQ (r = 0.203, p = 0.017) and with Wechsler Memory Scale-Revised attention/concentration score (r = 0.191, p = 0.025).
Different patterns of regional brain atrophy were found among patients of different APOE genotypes. The effect of APOE epsilon 4 allele on the brains of AD patients may have regional specificity.
Neurology 11/2001; 57(8):1461-6. · 8.31 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To examine the current emergency referral and care for acute stroke at a Japanese tertiary emergency hospital with a 24-h stroke team and care unit, we surveyed the presentations of patients with acute ischemic stroke or transient ischemic attack (TIA) seen within 7 days of onset. Delay from symptom onset to arrival at our hospital, from arrival to initial diagnostic brain computed tomography (CT), and the type of anti-thrombotic treatments were evaluated. During the 18-month period, there were 254 ischemic events in 244 patients; 239 (94%) had an ischemic stroke and 15 (6%) TIA. Eighty-two (32%) events presented within 3 h of onset, and 102 (40%) and 179 (70%) within the first 6 and 24 h, respectively. The median delay from hospital arrival to CT was 32 min, ranging 10 min to 22 h. Two hundred (79%) events underwent CT within 1 h of arrival (n=172) or at the referral hospitals before transfer (n=28). Direct ambulance transportation and more severe neurological deficits were independent predictors both for early arrival and short in-hospital delay to CT. Anti-thrombotic therapies including anticoagulant and/or antiplatelet medications were given in 237 (93%) episodes. Two (1%) patients received thrombolysis, although 18 (7%) patients fulfilled the National Institute of Neurological Disorders and Stroke guidelines for intravenous thrombolysis with tissue plasminogen activator. As in western communities, our pre-hospital emergency referral systems for acute stroke require substantial improvements including the wider use of ambulance calling. Although our in-hospital stroke management is functioning relatively well, further efforts are necessary in reducing the diagnostic delay.
European Journal of Neurology 10/2001; 8(5):483-8. · 3.69 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Stroke is a serious complication of coronary artery bypass grafting (CABG). Preoperative evaluation of the cerebral arteries to identify patients at increased risk of stroke after CABG is important. In a prospective study, we evaluated cerebral artery occlusive lesions with MR angiography in Japanese patients scheduled to undergo CABG to determine the prevalence of occlusive diseases in the extracranial carotid and intracranial arteries in this population and to identify preoperative risk factors for these patients.
The subjects were 151 consecutive patients (115 men and 36 women ranging in age from 41 to 82 years) who were scheduled for CABG under nonemergency conditions between October 1995 and February 1998. Carotid and intracranial arteries were examined for occlusive lesions with MR angiography. Patient demographics and risk factors including age, sex, hypertension, diabetes mellitus, hyperlipidemia, smoking habit, history of stroke, peripheral vascular disease and preoperative thromboembolic infarcts revealed by MR imaging were recorded and analyzed.
Cervical carotid artery stenoses of more than 50% narrowing were detected in 16.6% of the subjects, and intracranial artery stenoses of more than 50% narrowing were detected in 21.2% of the subjects. Multiple logistic regression analyses identified peripheral vascular disease and lacunar infarcts in the basal ganglia as significant and independent predictors of cervical carotid arterial stenoses. No significant predictor for intracranial arterial stenoses was identified.
The prevalence of extracranial carotid and intracranial artery stenosis in Japanese patients scheduled for CABG is considerably high. MR angiography is of value of identifying these patients. Preoperative evaluation of cranial arteries is recommended, particularly in patients with peripheral vascular disease and infarcts in the basal ganglia.
Cerebrovascular Diseases 02/2001; 11(4):341-5. · 2.72 Impact Factor
-
Cerebrovascular Diseases 02/2001; 12(3):283-4. · 2.72 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We developed cerebral perfusion Z score map (Z map) images using H(2)15O and positron emission tomography (PET), and examined their use in diagnosing Alzheimer's disease (AD). Cerebral blood flow (CBF) images were obtained using the PET and H(2)15O autoradiographic method. The best region for normalising the CBF value to remove individual variantion was determined. Then CBF images were transformed to Talairach's standard space, and each pixel value of an individual's image set was normalized to the mean value of the sensorimotor area. Based on the CBF images of 20 normal volunteers, normative mean and standard deviation (SD) CBF images were constructed. Then, each pixel value of the axial CBF images in 28 patients with probable AD and 10 further normal volunteers was converted to a Z score (Z = [normal mean--individual value]/normal SD). A Z map, showing pixels exceeding a threshold of Z score > 2 on MRI of standardised anatomical space was demonstrated. These 38 Z maps were interpreted by four radiologists. When regions in the temporoparietal area were found with Z scores > 2, the subject was diagnosed as having AD. A receiver operating characteristic (ROC) analysis was performed to compare the conventional CBF images and Z maps. The diagnostic performance of the Z map was superior to that of visual inspection of conventional CBF images (mean areas under the ROC curve of the four radiologists were 0.946 and 0.584, respectively). These results indicate that a Z map obtained in this way is superior to conventional PET for diagnosing AD.
Neuroradiology 11/2000; 42(11):787-94. · 2.82 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In an earlier study we showed that a powerful emotional experience (the Kobe earthquake) reinforced memory retention in patients with Alzheimer's disease, but we could not control factors other than the emotional impact of the earthquake.
To test our previous findings in a controlled experimental study.
Recall tests consisting of two short stories were administered to 34 patients with Alzheimer's disease and 10 normal subjects. The two stories were identical except for one passage in each story: one was emotionally charged (arousing story) and the other (neutral story) was not.
In both groups, the emotionally charged passage in the arousing story was remembered better than the counterpart in the neutral story. In addition, the extent of the memory improvement was similar in the subjects and in the controls.
The results provide further evidence that emotional arousal enhances declarative memory in patients with Alzheimer's disease, and give a clue to the management of people with dementia.
The British Journal of Psychiatry 11/2000; 177:343-7. · 6.62 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We developed cerebral perfusion Z score map (Z map) images using H2
15O and positron emission tomography (PET), and examined their use in diagnosing Alzheimer's disease (AD). Cerebral blood flow
(CBF) images were obtained using the PET and H2
15O autoradiographic method. The best region for normalising the CBF value to remove individual variantion was determined. Then
CBF images were transformed to Talairach's standard space, and each pixel value of an individual's image set was normalized
to the mean value of the sensorimotor area. Based on the CBF images of 20 normal volunteers, normative mean and standard deviation
(SD) CBF images were constructed. Then, each pixel value of the axial CBF images in 28 patients with probable AD and 10 further
normal volunteers was converted to a Z score (Z = [normal mean – individual value]/normal SD). A Z map, showing pixels exceeding
a threshold of Z score > 2 on MRI of standardised anatomical space was demonstrated. These 38 Z maps were interpreted by four
radiologists. When regions in the temporoparietal area were found with Z scores > 2, the subject was diagnosed as having AD.
A receiver operating characteristic (ROC) analysis was performed to compare the conventional CBF images and Z maps. The diagnostic
performance of the Z map was superior to that of visual inspection of conventional CBF images (mean areas under the ROC curve
of the four radiologists were 0.946 and 0.584, respectively). These results indicate that a Z map obtained in this way is
superior to conventional PET for diagnosing AD.
Neuroradiology 10/2000; 42(11):787-794. · 2.82 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: There have been conflicting results involving the clinical significance of white matter changes in patients with Alzheimer's disease (AD). We studied the association between the volume of white matter hyperintensities (WMHs) on T2-weighted images and cognitive, neurological, and neuropsychiatric symptoms.
The subjects were 76 AD patients who had WMHs but no obvious cerebrovascular diseases. We quantified the volume of WMHs by using fast-fluid-attenuated inversion recovery images and whole brain atrophy by using 3D spoiled gradient-echo images. Effects of WMHs and brain atrophy on dementia severity, cognitive function, neuropsychiatric disturbances, and neurological findings were examined.
Whole brain atrophy was significantly associated with dementia severity and cognitive disturbances, as well as with grasp reflex and some kinds of neuropsychiatric disturbances. After we controlled for the effects of brain atrophy, duration of symptoms, and demographic factors, we found that WMH volume was not associated with global cognitive disturbances or dementia severity but was significantly associated with urinary incontinence, grasp reflex, and aberrant motor behaviors. Brain atrophy and WMH volume were not significantly correlated either before or after controlling for age, sex, education, and duration of symptoms. WMH volume was associated with hypertension, but brain atrophy was not positively correlated with any vascular risk factors.
Our results support the hypothesis that WMHs in AD patients are superimposed phenomena of vascular origin. WMHs contribute to specific neurological and neuropsychiatric manifestations but not to global cognitive impairment, which is more closely associated with brain atrophy.
Stroke 10/2000; 31(9):2182-8. · 5.73 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: By using functional magnetic resonance imaging (fMRI), the neural substrates involved in mental recitation of the single-digit multiplication table and serial subtraction were studied. The former depends mostly on well-learned arithmetical facts, while the latter requires arithmetic processing. Activation during each task was compared with that in a number counting control. During the recitation of single-digit multiplication, the activated regions included the area lying along the left intraparietal sulcus, the premotor and supplementary motor areas, and the posterior portion of the left inferior frontal gyrus. The areas activated during serial subtraction included these areas as well as the bilateral prefrontal and right parietal areas. From the results obtained during retrieval of the multiplication table in this study and previous studies, it was concluded that semantic memory of the multiplication table is stored in the area lying along the intraparietal sulcus and that the frontal areas play an executive role in utilizing the semantic memory of arithmetical facts. It was assumed that the arithmetical facts requiring actual calculation are also stored in the same region. The additional activation during serial subtraction compared with the activation during retrieval of the multiplication table is probably due to the processes of actual calculation. These processes include proper alignment of digits, which may have caused the right parietal activation, and maintaining digits needed for the mental serial subtractions, which may have caused the bilateral prefrontal activation.
Psychiatry and Clinical Neurosciences 09/2000; 54(4):479-85. · 2.13 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Donepezil has been licensed for use in Japan to improve cognitive function since 1999. Among 94 patients with probable Alzheimer's disease who we treated with donepezil, seven patients developed urinary incontinence, although this event was transient in most patients.
The Lancet 09/2000; 356(9229):568. · 38.28 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This paper proposes an automated procedure for segmenting an magnetic resonance (MR) image of a human brain based on fuzzy logic. An MR volumetric image composed of many slice images consists of several parts: gray matter, white matter, cerebrospinal fluid, and others. Generally, the histogram shapes of MR volumetric images are different from person to person. Fuzzy information granulation of the histograms can lead to a series of histogram peaks. The intensity thresholds for segmenting the whole brain of a subject are automatically determined by finding the peaks of the intensity histogram obtained from the MR images. After these thresholds are evaluated by a procedure called region growing, the whole brain can be identified. A segmentation experiment was done on 50 human brain MR volumes. A statistical analysis showed that the automated segmented volumes were similar to the volumes manually segmented by a physician. Next, we describe a procedure for decomposing the obtained whole brain into the left and right cerebral hemispheres, the cerebellum and the brain stem. Fuzzy if-then rules can represent information on the anatomical locations, segmentation boundaries as well as intensities. Evaluation of the inferred result using the region growing method can then lead to the decomposition of the whole brain. We applied this method to 44 MR volumes. The decomposed portions were statistically compared with those manually decomposed by a physician. Consequently, our method can identify the whole brain, the left cerebral hemisphere, the right cerebral hemisphere, the cerebellum and the brain stem with high accuracy and therefore can provide the three dimensional shapes of these regions.
IEEE Transactions on Systems Man and Cybernetics Part C (Applications and Reviews) 09/2000; · 2.01 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the characteristics of cortical atrophy in corticobasal degeneration and Alzheimer disease by using a hemispheric surface display generated with magnetic resonance (MR) images.
The magnitude and extent of cortical atrophy were evaluated with MR hemispheric surface display and volumetric measurement in three groups: 17 patients with corticobasal degeneration, 17 matched patients with Alzheimer disease, and 17 matched healthy control subjects.
The extent and magnitude of cortical atrophy were larger in the group with corticobasal degeneration than in the group with Alzheimer disease. The parasagittal and paracentral regions were significantly more atrophic in patients with corticobasal degeneration than in patients with Alzheimer disease (P <.05). The mean hemispheric-to-total intracranial volume ratios were significantly smaller in the patients with corticobasal degeneration (61%) and those with Alzheimer disease (64%) than in control subjects (69%). Asymmetry of hemispheric volume was significantly larger in the group with corticobasal degeneration than in the control group.
The extent of cortical atrophy in corticobasal degeneration is more widespread than was previously thought. Parasagittal and paracentral atrophy is a distinctive feature of corticobasal degeneration and distinguishes it from Alzheimer disease.
Radiology 08/2000; 216(1):31-8. · 5.73 Impact Factor
