Vegetable Freshness Perception in Dementia with Lewy Bodies and Alzheimer's Disease.

INTRODUCTION: Although various visual function deficits have been reported in patients with Alzheimer's disease (AD) and dementia with Lewy bodies (DLB), vegetable freshness perception has not been thoroughly examined. OBJECTIVE: To investigate vegetable freshness perception in patients with AD and DLB and to clarify the relationship between vegetable freshness perception and various visuoperceptual functions. METHODS: We enrolled 37 patients with probable DLB, 58 patients with probable AD, and 32 age-matched healthy controls. We assessed vegetable freshness perception and visuoperceptual functions, including vegetable brightness perception, contrast sensitivity, color perception, and stereopsis. Patients with DLB showed disproportionate deficits in vegetable freshness perception and vegetable luminance perception compared to patients with AD and controls. Analyses of the groups with higher and lower vegetable freshness perceptions revealed significant differences in contrast sensitivity and visual texture recognition. RESULTS: In the vegetable freshness test, we found significant differences among the 3 groups (F = 30.029, p < 0.0001); the extent of impairment in patients with DLB was greater than that in patients with AD. In patients with DLB, the vegetable freshness judgments were significantly correlated with texture judgment scores and contrast sensitivity. CONCLUSION: Our findings revealed significantly impaired vegetable freshness perception in patients with DLB. Vegetable freshness perception may be related to visual texture recognition in patients with DLB.

Visual texture agnosia influences object identification in dementia with Lewy bodies and Alzheimer's disease.

BACKGROUND: Numerous studies have shown visuoperceptual/visuospatial deficits in dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Visual texture recognition is also impaired in patients with DLB and AD. Although patients with DLB often exhibit visual misidentifications of objects, there are few studies on the relationships between visual texture recognition and viewpoints for object recognition. OBJECTIVES: The aim of this study was to clarify how viewpoints, textures, and visual cognitive functions affect object recognition and result in visual misidentifications in patients with DLB or AD. METHODS: A total of 37 patients with probable DLB and 58 with probable AD and 32 age-matched healthy controls underwent neuropsychological and visuoperceptual assessments, and performed object identification tasks under four conditions (non-canonical view + blurry texture, non-canonical view + clear texture, canonical view + blurry texture, canonical view + clear texture). The relationship between object identification and other visuoperceptual functions was analyzed. RESULTS: Patients with DLB and AD exhibited significantly impaired object recognition under non-canonical viewing with blurry texture conditions, with the DLB patients exhibiting a significantly worse performance than the AD patients. Patients with DLB and AD exhibited visual misidentifications during object identification tasks under non-canonical viewing. In patients with DLB, the number of visual misidentifications was significantly correlated with the scores of visual texture recognition. CONCLUSIONS: The present study showed that significantly impaired object recognition in patients with DLB under the influences by both viewpoint and visual texture and in those with AD under the influence by viewpoint. Visual misidentification in object recognition could be associated with impaired visual texture recognition in DLB.

Negative mood invites psychotic false perception in dementia.

BACKGROUND: There is increasing evidence for predictive coding theories of psychosis, which state that hallucinations arise from abnormal perceptual priors or biases. However, psychological processes that foster abnormal priors/biases in patients suffering hallucinations have been largely unexplored. The widely recognized relationship between affective disorders and psychosis suggests a role for mood and emotion. METHODS: Thirty-six patients with dementia with Lewy bodies (DLB), a representative condition associated with psychosis of neurological origin, and 12 patients with Alzheimer's disease (AD) were enrolled. After an experimental mood induction, the participants underwent the pareidolia test, in which visual hallucination-like illusions were evoked and measured. RESULTS: In DLB patients, the number of pareidolic illusions was doubled under negative mood compared to that under neutral mood. In AD patients, there was no significant difference in the number of pareidolic responses between negative and neutral mood conditions. A signal detection theory analysis demonstrated that the observed affective modulation of pareidolic illusions was mediated through heightened perceptual bias, not sensory deterioration. CONCLUSIONS: The current findings demonstrated that abnormal perceptual priors in psychotic false perception have an affective nature, which we suggest are a type of cognitive feeling that arises in association with perception and cognition.

Visual texture agnosia in dementia with Lewy bodies and Alzheimer's disease.

BACKGROUND: Neuroimaging and some clinical studies have reported that the ventral visual pathway is relevant for visual texture recognition. Although a variety of visual deficits have been reported in patients with Alzheimer's disease (AD) and dementia with Lewy bodies (DLB), visual material identification and texture recognition have not been thoroughly examined. OBJECTIVES: To investigate visual texture recognition in patients with AD and DLB and to clarify the relationship between visual texture recognition and various visuoperceptual functions. METHODS: Twenty-five patients with probable DLB, 53 patients with probable AD, and 32 age-matched healthy controls were included. We assessed visual texture recognition of real materials/images and visuoperceptual functions including contrast sensitivity, color perception, stereopsis, shape detection, and position in space. RESULTS: DLB patients showed disproportionate deficits in visuoperceptual functions and visual texture recognition compared with AD patients and controls, but these dysfunctions were not correlated with each other. AD patients had significantly impaired visual texture recognition but with intact visuoperceptual functions, except contrast sensitivity. Using an optimal cut-off score according to the receiver operating characteristic (ROC) curve analysis, the results from the visual texture recognition of images could differentiate DLB patients from controls with a sensitivity of 92% and a specificity of 97%. CONCLUSIONS: We demonstrated significantly impaired visual texture recognition in patients with DLB and AD, with patients with DLB performing significantly worse than patients with AD. Additionally, visual texture recognition and visuoperceptual functions are independently disturbed in DLB.

Changes in pupil diameter are correlated with the occurrence of pareidolias in patients with dementia with Lewy bodies.

Pareidolias are visual illusions of meaningful objects, such as faces and animals, that arise from ambiguous forms embedded in visual scenes. Pareidolias and visual hallucinations have been suggested to have a common underlying neural mechanism in patients with dementia with Lewy bodies (DLB). The aim of the present study was to find an externally observable physiological indicator of pareidolias. Using a pareidolia test developed by Uchiyama and colleagues, we evoked pareidolias in patients with DLB and recorded the resultant changes in the diameters of their pupil. The time frequencies of changes in pupil diameters preceding pareidolic utterances and correct utterances by the patients, as well as correct utterances by healthy control participants, were analyzed by a fast Fourier transform program. The power at time frequencies of 0-0.46 Hz was found to be greatest preceding pareidolic utterances in patients with DLB, followed by that preceding correct utterances in control participants, followed by that preceding correct utterances in patients with DLB. When the changes in power preceding the utterance were greater than the median value of correct utterances by the control group, the frequency of pareidolic utterances was significantly greater than that of correct utterances and when the changes were the same as or lower than the median value, the frequency of correct utterances was significantly greater than that of pareidolic utterances. Greater changes in power preceding the utterance at time frequencies of 0-0.46 Hz may thus be an externally observable physiological indicator of the occurrence of pareidolias.

Sleep disturbances are key symptoms of very early stage Alzheimer disease with behavioral and psychological symptoms: a Japan multi-center cross-sectional study (J-BIRD).

BACKGROUND: Sleep disturbances in Alzheimer disease (AD) may affect behavioral and psychological symptoms of dementia (BPSD). Our aim was to elucidate the associations between sleep disturbances and other BPSD at different stages of AD. METHODS: This investigation was part of a multicenter-retrospective study in Japan (J-BIRD). Eligible for final analyses were 684 AD patients. Global severity of dementia was estimated using the Clinical Dementia Rating (CDR) scale. BPSD were assessed using the Neuropsychiatric Inventory (NPI). We analyzed the relationships between sleep disturbances and BPSD at different stages of AD according to the CDR score. RESULTS: Among the 684 AD patients, 146 (21.3%) had sleep disturbances. Patients with very early AD (CDR 0.5) and sleep disturbances had significantly more BPSD than those without sleep disturbances, as indicated by the higher prevalence of the following four NPI items: anxiety, euphoria, disinhibition, and aberrant motor behavior. In AD at CDR 2, (moderate AD) only one NPI item (irritability) was affected, while none was affected at CDR 1 (mild AD) and 3 (severe AD). Multiple regression analyses were performed in those with AD having various CDR scores. At CDR 0.5, the presence of sleep disturbances was associated with a high total NPI score (ß = 0.32, p < 0.001). However, other factors, including cognitive decline, age, gender, and years of education, were not significantly associated with the NPI score. At CDR 1 and 2, no factor was significantly related to BPSD. CONCLUSION: Sleep disturbances were strongly associated with other BPSD in the very early stage of AD. Copyright © 2016 John Wiley & Sons, Ltd.

Differences of Behavioral and Psychological Symptoms of Dementia in Disease Severity in Four Major Dementias.

BACKGROUND/AIMS: Behavioral and psychological symptoms of dementia (BPSDs) negatively impact the prognosis of dementia patients and increase caregiver distress. The aims of this study were to clarify the differences of trajectories of 12 kinds of BPSDs by disease severity in four major dementias and to develop charts showing the frequency, severity, and associated caregiver distress (ACD) of BPSDs using the data of a Japan multicenter study (J-BIRD). METHODS: We gathered Neuropsychiatric Inventory (NPI) data of patients with Alzheimer's disease (AD; n = 1091), dementia with Lewy bodies (DLB; n = 249), vascular dementia (VaD; n = 156), and frontotemporal lobar degeneration (FTLD; n = 102) collected during a 5-year period up to July 31, 2013 in seven centers for dementia in Japan. The NPI composite scores (frequency × severity) of 12 kinds of items were analyzed using a principal component analysis (PCA) in each dementia. The factor scores of the PCA were compared in each dementia by disease severity, which was determined with Clinical Dementia Rating (CDR). RESULTS: Significant increases with higher CDR scores were observed in 1) two of the three factor scores which were loaded for all items except euphoria in AD, 2) two of the four factor scores for apathy, aberrant motor behavior (AMB), sleep disturbances, agitation, irritability, disinhibition, and euphoria in DLB, and 3) one of the four factor scores for apathy, depression, anxiety, and sleep disturbances in VaD. However, no increases were observed in any of the five factor scores in FTLD. CONCLUSIONS: As dementia progresses, several BPSDs become more severe, including 1) apathy and sleep disturbances in AD, DLB, and VaD, 2) all of the BPSDs except euphoria in AD, 3) AMB, agitation, irritability, disinhibition, and euphoria in DLB, and 4) depression and anxiety in VaD. Trajectories of BPSDs in FTLD were unclear.

The Pareidolia Test: A Simple Neuropsychological Test Measuring Visual Hallucination-Like Illusions.

BACKGROUND: Visual hallucinations are a core clinical feature of dementia with Lewy bodies (DLB), and this symptom is important in the differential diagnosis and prediction of treatment response. The pareidolia test is a tool that evokes visual hallucination-like illusions, and these illusions may be a surrogate marker of visual hallucinations in DLB. We created a simplified version of the pareidolia test and examined its validity and reliability to establish the clinical utility of this test. METHODS: The pareidolia test was administered to 52 patients with DLB, 52 patients with Alzheimer's disease (AD) and 20 healthy controls (HCs). We assessed the test-retest/inter-rater reliability using the intra-class correlation coefficient (ICC) and the concurrent validity using the Neuropsychiatric Inventory (NPI) hallucinations score as a reference. A receiver operating characteristic (ROC) analysis was used to evaluate the sensitivity and specificity of the pareidolia test to differentiate DLB from AD and HCs. RESULTS: The pareidolia test required approximately 15 minutes to administer, exhibited good test-retest/inter-rater reliability (ICC of 0.82), and moderately correlated with the NPI hallucinations score (rs = 0.42). Using an optimal cut-off score set according to the ROC analysis, and the pareidolia test differentiated DLB from AD with a sensitivity of 81% and a specificity of 92%. CONCLUSIONS: Our study suggests that the simplified version of the pareidolia test is a valid and reliable surrogate marker of visual hallucinations in DLB.

[Dominant Thalamus and Aphasia].

Many studies have shown that lesions of the dominant thalamus precipitate language disorders in a similar manner to transcortical aphasias, in a phenomenon known as "thalamic aphasia." In some cases, however, aphasia may not occur or may appear transiently following thalamic lesions. Furthermore, dominant thalamic lesions can produce changes in character, as observed in patients with amnesic disorder. Previous work has explored the utility of thalamic aphasia as a discriminative feature for classification of aphasia. Although the thalamus may be involved in the function of the brainstem reticular activating system and play a role in attentional network and in memory of Papez circuit or Yakovlev circuit, the mechanism by which thalamic lesion leads to the emergence of aphasic disorders is unclear. In this review, we we survey historical and recent literature on thalamic aphasia in an attempt to understand the neural processes affected by thalamic lesions.

Hallucinators find meaning in noises: pareidolic illusions in dementia with Lewy bodies.

By definition, visual illusions and hallucinations differ in whether the perceived objects exist in reality. A recent study challenged this dichotomy, in which pareidolias, a type of complex visual illusion involving ambiguous forms being perceived as meaningful objects, are very common and phenomenologically similar to visual hallucinations in dementia with Lewy bodies (DLB). We hypothesise that a common psychological mechanism exists between pareidolias and visual hallucinations in DLB that confers meaning upon meaningless visual information. Furthermore, we believe that these two types of visual misperceptions have a common underlying neural mechanism, namely, cholinergic insufficiency. The current study investigated pareidolic illusions using meaningless visual noise stimuli (the noise pareidolia test) in 34 patients with DLB, 34 patients with Alzheimer׳s disease and 28 healthy controls. Fifteen patients with DLB were administered the noise pareidolia test twice, before and after donepezil treatment. Three major findings were discovered: (1) DLB patients saw meaningful illusory images (pareidolias) in meaningless visual stimuli, (2) the number of pareidolic responses correlated with the severity of visual hallucinations, and (3) cholinergic enhancement reduced both the number of pareidolias and the severity of visual hallucinations in patients with DLB. These findings suggest that a common underlying psychological and neural mechanism exists between pareidolias and visual hallucinations in DLB.

Pareidolias: complex visual illusions in dementia with Lewy bodies.

Patients rarely experience visual hallucinations while being observed by clinicians. Therefore, instruments to detect visual hallucinations directly from patients are needed. Pareidolias, which are complex visual illusions involving ambiguous forms that are perceived as meaningful objects, are analogous to visual hallucinations and have the potential to be a surrogate indicator of visual hallucinations. In this study, we explored the clinical utility of a newly developed instrument for evoking pareidolic illusions, the Pareidolia test, in patients with dementia with Lewy bodies-one of the most common causes of visual hallucinations in the elderly. Thirty-four patients with dementia with Lewy bodies, 34 patients with Alzheimer's disease and 26 healthy controls were given the Pareidolia test. Patients with dementia with Lewy bodies produced a much greater number of pareidolic illusions compared with those with Alzheimer's disease or controls. A receiver operating characteristic analysis demonstrated that the number of pareidolias differentiated dementia with Lewy bodies from Alzheimer's disease with a sensitivity of 100% and a specificity of 88%. Full-length figures and faces of people and animals accounted for >80% of the contents of pareidolias. Pareidolias were observed in patients with dementia with Lewy bodies who had visual hallucinations as well as those who did not have visual hallucinations, suggesting that pareidolias do not reflect visual hallucinations themselves but may reflect susceptibility to visual hallucinations. A sub-analysis of patients with dementia with Lewy bodies who were or were not treated with donepzil demonstrated that the numbers of pareidolias were correlated with visuoperceptual abilities in the former and with indices of hallucinations and delusional misidentifications in the latter. Arousal and attentional deficits mediated by abnormal cholinergic mechanisms and visuoperceptual dysfunctions are likely to contribute to the development of visual hallucinations and pareidolias in dementia with Lewy bodies.

Cognitive profile of idiopathic normal pressure hydrocephalus.

BACKGROUND/AIMS: Frontal lobe dysfunction is believed to be a primary cognitive symptom in idiopathic normal pressure hydrocephalus (iNPH); however, the neuropsychology of this disorder remains to be fully investigated. The objective of this study was to delineate a comprehensive profile of cognitive dysfunction in iNPH and evaluate the effects of cerebrospinal fluid (CSF) shunt surgery on cognitive dysfunction. METHODS: A total of 32 iNPH patients underwent neuropsychological testing of memory, attention, language, executive function, and visuoperceptual and visuospatial abilities. Of these 32 patients, 26 were reevaluated approximately 1 year following CSF shunt surgery. The same battery of tests was performed on 32 patients with Alzheimer's disease (AD) and 30 healthy elderly controls. RESULTS: The iNPH patients displayed baseline deficits in attention, executive function, memory, and visuoperceptual and visuospatial functions. Impairments of attention, executive function, and visuoperceptual and visuospatial abilities in iNPH patients were more severe than in those with AD, whereas the degree of memory impairment was comparable to that in AD patients. A significant improvement in executive function was observed following shunt surgery. CONCLUSION: Patients with iNPH are impaired in various aspects of cognition involving both 'frontal' executive functions and 'posterior cortical' functions. Shunt treatment can ameliorate executive dysfunction.

The effects of aging and Alzheimer's disease on associative recognition memory.

We investigated the effects of aging and Alzheimer's disease (AD) on item and associative recognition memory. Three groups of participants (younger adults, elderly adults, and AD patients) studied photographs of common objects that were located on either the left or the right side of a black computer screen inside either a red or a blue square. In a subsequent old/new recognition memory test, the participants were presented with four kinds of stimuli: "intact" stimuli, which were presented as they were during the study phase; "location-altered" stimuli, which were presented in a different location; "color-altered" stimuli, which were presented with a different surrounding color; and "new" stimuli, which consisted of photographs that had not been presented during the study phase. Compared with younger adults, the older adults showed equivalent performance in simple item recognition but worse performance in discriminating location-altered and color-altered stimuli. Compared with older adults, the AD patients showed equivalent performance in discriminating color-altered stimuli but worse performance in simple item recognition and the discrimination of location-altered stimuli. We speculate that distinct structural and functional changes in specific brain regions that are caused by aging and AD are responsible for the different patterns of memory impairment.

A novel mediator-polymer-modified anode for microbial fuel cells.

A high-performance anode system based on a combination of mediator-polymer-modified graphite felt and bacteria capable of reducing extracellular materials shows significant potential for practical use in microbial fuel cells (MFCs).

[Stereotyped behaviors and compulsive complaints of pain improved by fluvoxamine in two cases of frontotemporal dementia].

There have been no systematic efforts to manage and treat patients with frontotemporal dementia (FTD), but Perry described pharmacologic interventions for some behavioral syndromes in 2001. In Perry's report, selective serotonin reuptake inhibitors (SSRI) were recommended as first choice drugs because they were well tolerated and might have an effect on some symptoms such as compulsive symptoms and eating abnormalities. Some reports were presented concerning Japanese FTD patients which showed the effect of SSRI on stereotyped behaviors and eating abnormalities by Nishikawa, et al. (2001), Ikeda, et al. (2004), and others. We describe two FTD patients with compulsive complaints of pain, one mainly on abdomen and the other on lumbar region. Fluvoxamine markedly improved their complaints of pain as well as stereotyped symptoms. Fluvoxamine might be effective for behavioral disturbances due to improvement of serotoninergic dysfunction in frontal medial and cingulated cortices, as previously described. Moreover, it has been reported that an altered response to pain stimuli, either via a loss of awareness of pain or exaggerated reaction to pain, is a specific feature of FTD, but there have been only a few reports on this feature. Fluvoxamine might be effective for compulsive complaints of pain due to improvements of compulsive symptoms and exaggerated reactions to pain in FTD, or due to the analgesic effect of SSRI. SSRI may improve compulsive complaints of pain in FTD patients.

Reductive dechlorination of tetrachloroethene in a sand reactor using a potentiostat.

In this study, an electrochemical system was investigated to enhance abiotic dechlorination of chlorinated solvents in contaminated soil in situ. A potentiostatic electrolysis sand reactor was developed and tested to evaluate tetrachloroethene (PCE) dechlorination in saturated sand. When operated with recirculating nutrient-supplemented water the reactor sustained a low oxidation reduction potential (ORP) at the cathode (<-400 mV standard hydrogen electrode [SHE]), a pH less than 9.4, and electric current >5 mA at room temperature with the cathodic potential controlled at -950 mV SHE. Tetrachloroethene in the electrolysis reactor had a half-life of 6.8 d compared with the control bioreactor without electrolysis, which had a PCE half-life of 16.4 d. Ethane and ethene were the main dechlorination products in the test reactor, while trichloroethene (TCE) accumulated in the nutrient-amended control reactor without electrolysis. An electrolysis reactor operated with water not amended with nutrients showed a PCE half-life of 7.6 d, suggesting that most of dechlorination activity in the reactor was abiotic. Since complete dechlorination can be achieved under moderate pH and temperature, this type of electrolysis technology is attractive as a remedial method for subsurface chloroethene contamination.