Toshiya Fukui

Cognitive Functions in Subjects with Incidental Cerebral Hyperintensities

We investigated the association between incidental cerebral hyperintensities (CH) found by magnetic resonance imaging (MRI) and cognitive functions in neurologically normal, nondemented subjects. Semiquantitative scores for MRI lesions and those for brain atrophy were compared with the results of extensive cognitive examinations using multivariate analysis. There was no correlation between CH and cognition, except that periventricular hyperintensities, especially those in posterior locations, were associated with reduced performance in the Stroop test. Overall cognitive functions were associated with age, and age was a predominant factor in the prefrontal functions. Brain atrophy was associated more with decline of the posterior and dorsolateral frontal brain functions. We suggest that disturbances in attention and speed may initially result from incidental CH, while other cognitive functions remain unaffected.

Progressive agraphia can be a harbinger of degenerative dementia

By investigating three patients with progressive agraphia, we explored the possibility that this entity is an early sign of degenerative dementia. Initially, these patients complained primarily of difficulties writing Kanji (Japanese morphograms) while other language and cognitive impairments were relatively milder. Impairments in writing Kana (Japanese syllabograms), verbal language, executive function, visuo- and visuospatial cognition and memory were identified by neuropsychological testing. The agraphia was compatible with a peripheral type, based on deficits at the interface between the central letter selection and the graphemic motor execution (Patient 1) or at the stage of central letter selection as well (Patients 2 and 3). Agraphia was generally more prominent, although not exclusive, for Kanji probably because of later acquisition and larger total number of Kanji letters leading to lower frequency of use and familiarity per letter. Concurrent or subsequent emergence of non-fluent aphasia, ideomotor apraxia, executive dysfunction and asymmetric akinetic-rigid syndrome in two patients suggested degenerative processes involving the parietal-occipital-temporal regions, basal ganglia and striato-frontal projections. We propose that progressive agraphia may be one of the early symptoms of degenerative dementia such as corticobasal degeneration.

Prevalence and Clinical Implication of Microbleeds in Dementia with Lewy Bodies in Comparison with Microbleeds in Alzheimer's Disease

Background: Cerebral microbleeds (MBs) have been well investigated in Alzheimers disease (AD), but not very extensively in non-AD dementias or in dementia with Lewy bodies (DLB). Aims: To elucidate the clinical significance of MBs in DLB. Methods: We compared the prevalence, locations and risk factors for MBs in 59 DLB and 81 AD patients. We visually counted MBs in each of the cortical and subjacent areas (frontal, temporal, parietal and occipital), the basal ganglia and the thalamus, and the brainstem and the cerebellar hemispheres on 1.5-tesla T2*-weighted gradient-recalled-echo MRI images. White matter lesions were semiquantified in fluid-attenuated inversion recovery images according to the Fazekas rating scale. Results: While the prevalence of MBs was comparable, MBs tended to be more abundant in DLB than in AD in all brain areas with the exception of the occipital lobes. The number of MBs was positively associated with the severity of white matter lesions but not with other vascular risk factors in either AD or DLB. The presence of MBs could be associated with cognitive impairment at onset. MB-positive DLB patients showed less impairment on 123I-metaiodobenzylguanidine myocardial scintigraphy (MIBG scintigraphy) images, supporting the notion of an inverse relationship between vascular lesions and Lewy body pathology. Conclusion: It was suggested that an intricate association between Lewy body pathology, AD-type pathologies and vascular lesions seems to be related to the initial symptoms and results of MIBG scintigraphy in DLB.

Utilization Behavior and Concomitant Motor Neglect by Bilateral Frontal Lobe Damage

We reported on a patient who had bilateral mesial frontal lesions, presumably of a primary cerebral malignant lymphoma. The patient presented with a combination of unusual behavioral disorders of the upper extremities, which has not yet been documented in the literature: bilateral utilization and imitation behaviors and motor neglect of the left arm. Utilization behavior was closely associated with bilateral manual grasping behavior and was caused by the bifrontal lesions. Damage to the right supplementary motor area resulted most likely in concomitant motor neglect of the left hand. Discussion includes differentiation from other related behavioral disorders.

Visuospatial Function is a Significant Contributor to Functional Status in Patients With Alzheimer’s Disease

Background: Contribution of visuospatial abilities to the functional status in patients with Alzheimer’s disease (AD) has been controversial. Aim: To address whether visuospatial abilities have independent association with functional measures in patients with AD. Methods: We regressed performances on a global cognitive (the revised Hasegawa Dementia Scale: HDSR), executive/ visuoconstruction (Clock drawing), visuoperception (Clock reading: CRT), simple visuoconstruction (figure copying), and frontal behavioral tasks on measures of basic and instrumental activities of daily living (BADL and IADL) in 57 patients (78.0 + 6.1 years) with AD of various severity (mean HDSR score: 16.0 + 5.9). We sought independent contributions of these visuospatial measures to functional status. Results: Performance on the CRT contributed significantly to BADL and IADL and the results of HDSR contributed to IADL. Results of figure copying related significantly to BADL especially in mild AD. Conclusion: Visuospatial ability is one of the important contributors to functional status.

Visuospatial Dysfunction May Be a Key in the Differentiation between Alzheimer’s Disease and Subcortical Cognitive Impairment in Moderate to Severe Stages

Aims: Recent studies have suggested that subcortical cognitive impairment (SubCI) and Alzheimer’s disease (AD) can be differentiated by visuospatial tasks. We addressed at what severity stage these differences become apparent and what components in visuospatial processes are subject to impairment. Methods: Sixty patients with AD, 22 with vascular cognitive impairment and 63 with extrapyramidal diseases with cognitive impairment were assessed using the revised Hasegawa Dementia Scale (HDSR), clock drawing/reading/matching tests (CDT, CRT, CMT), figure copying (FIG) and Frontal Assessment Battery (FAB). Patients were categorized according to the HDSR scores in order to control for the severity of global cognitive impairment. Raw scores were converted to Z-scores for comparisons. Results: In the mild stage, results of all measures were comparable between AD and SubCI. In the moderate-severe stage, scores of CDT, CRT, CMT, FIG and FAB were significantly lower in SubCI. The results suggest that (given that global cognition is controlled for) visuo-perception, visuo-construction and semantic-numerical analyses of visual information may be more impaired in SubCI than AD. Conclusions: AD and SubCI may be difficult to be differentiated in the mild stages, and the visuospatial cognitive system may be extensively defective in SubCI.

Distribution of basal ganglia lesions in Pick's disease with Pick bodies: A topographic neuropathological study of eight autopsy cases

The distribution of the basal ganglia lesions, including the amygdala, striatum, and pallidum, were investigated neuropathologically in eight Japanese autopsy cases of Picks disease with Pick bodies. The lesions were classified as mild, moderate or severe. The degree and distribution of basal ganglia lesions in all eight cases were uniform: the amygdala showed severe to moderate lesions, the caudate nucleus and putamen showed moderate to mild lesions, and the pallidum showed mild lesions. Furthermore, the lesions in the amygdala were more prominent in the basolateral group than in the corticomedial group. In Picks disease with Pick bodies, the degree and distribution of the lesions within the basal ganglia differs from those reported in both ‘Picks disease without Pick bodies’ and corticobasal degeneration (CBD), in which severe lesions were present in the pallidum. These neuropathological findings may contribute to the morphological differential diagnosis among Picks disease with Pick bodies, ‘Picks disease without Pick bodies’, and CBD.

Can the 'head-turning sign' be a clinical marker of Alzheimer's disease?

Aims: To investigate the incidence and severity of the ‘head-turning sign’ (HTS), i.e. turning the head back to the caregiver(s) for help, in patients with various dementias and discuss its clinical specificity in Alzheimer’s disease (AD). Methods: We investigated the incidence and severity of HTS while administering a short cognitive test (the revised Hasegawa Dementia Rating Scale: HDSR) in outpatients with AD [125 patients, including 4 with AD + vascular dementia (VaD)], 8 with amnestic mild cognitive impairment (aMCI), 34 with dementia with Lewy bodies (DLB), 8 with progressive supranuclear palsy (PSP) and 6 with VaD. Results: Significant differences were found among the 5 disease groups in the incidence and severity of HTS, and HDSR scores. Given the significant differences between AD and DLB in post hoc analyses, patients were dichotomized into AD-related (AD and aMCI) and AD-nonrelated (PSP, DLB and VaD) groups. Both incidence (41 vs. 17%, p = 0.002) and severity of HTS (0.80 ± 1.13 vs. 0.21 ± 0.60, p = 0.001) were significantly higher in the AD-related group, while average age and HDSR scores were comparable between both groups. AD-related disease, female gender and low HDSR score contributed significantly to the occurrence and severity of HTS. Conclusions: HTS can be a clinical marker of AD and aMCI, and may represent a type of excuse behavior as well as a sign of dependency on and trust in the caregivers.

Do Vascular Lesions and Related Risk Factors Influence Responsiveness to Donepezil Chloride in Patients with Alzheimer’s Disease?

The purpose was to identify vascular influences on the responsiveness to donepezil chloride. The study included 50 untreated probable Alzheimer’s disease patients with the Modified Hachinski Ischemic Score <4. We assessed baseline cognitive status using the Revised Hasegawa Dementia Scale (HDS-R), Clinical Dementia Rating (CDR) and the clock drawing test (CDT). The response to 5 mg of donepezil was monitored by the CDT for 12 months. Patients were classified as true responders (TR), unchanged (UC) and non-responders according to changes on the CDT in response to treatment. High HDS-R scores, low CDT scores, low CDR and presence of hypertension (HBP) and periventricular hyperintensities (PVH) predicted a TR- or UC-type outcome. Aggravation of executive function by HBP and/or PVH and its improvement by donepezil may have been detected by the CDT.

SPECT-Identified Neuroanatomical Predictor of the Cognitive Effects of Donepezil Treatment in Patients with Alzheimer’s Disease

Background/Objective: We attempted to determine whether the pretreatment regional cerebral blood flow (rCBF) might predict cognitive changes in response to donepezil treatment, as assessed in terms of the Alzheimer Disease Assessment Scale cognitive subscale (ADAS-cog), and in relation to the severity of subcortical hyperintensities (SH). Method: Forty-one patients with Alzheimer’s disease (AD) were treated with donepezil at baseline. All the patients underwent a single photon emission computed tomography examination before donepezil therapy. They also completed the ADAS-cog at baseline and after 24 weeks of donepezil therapy. SH were assessed semiquantitatively using a recently developed visual rating scale. We analyzed the correlation between the baseline rCBF and changes in the ADAS-cog score using statistical parametric mapping, including the severity of the SH as a covariate. Results: Lower pretreatment rCBF levels in the right orbitofrontal cortex (OFC) predicted a better improvement in the ADAS-cog score in response to donepezil therapy. The severity of SH did not appear to influence this correlation. Conclusions: This effect may reflect the choline acetyltransferase activity associated with the OFC. The presence of SH did not appear to influence the effect of donepezil therapy on the cognitive function as assessed by ADAS-cog.