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.

These different regional CMRglc reductions substantiate the pathologic, neurochemical, and clinical differences between DLB and AD.

No abstract

Visual perception is defective in probable DLB. The defective visual perception plays a role in development of visual hallucinations, delusional misidentifications, visual agnosias, and visuoconstructive disability charcteristic of DLB.

No abstract

Background/AimsBehavioral 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).MethodsWe 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).ResultsSignificant 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.ConclusionsAs 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.

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.

Depression is common in Alzheimer's disease (AD). Clinicoanatomic studies in focal brain injuries and functional imaging studies both in primary depression and in depression secondary to neurologic diseases have demonstrated involvement of the frontal lobe. Frontal involvement has not been established in the depression of AD. We studied the correlation between focal brain metabolic abnormalities and depression in AD. In 53 patients with probable AD of minimal to moderate disability, we assessed the severity of depression using the Neuropsychiatric Inventory and correlated the depression score with regional cerebral glucose metabolism determined by 18F-fluorodeoxyglucose and PET. Depression was present in 19 patients (36%). The depression score correlated significantly with normalized glucose metabolic rates in the bilateral superior frontal and left anterior cingulate cortices. These results indicated an association between depression and decreased activity in the frontal lobe in AD and support frontal involvement, especially in the left side, in depression, irrespective of disease etiology.