Clinical and cognitive correlates of visual hallucinations in dementia with Lewy bodies

Abstract

Impairment of visual-spatial and perceptual abilities in DLB represents a disease related cognitive signature, independent of the presence of VHs, for which it may represent a predisposing condition. Visual attention, instead, is the main cognitive determinant for the genesis of VHs.

Cognitive phenotype of psychotic symptoms in Alzheimer's disease: evidence for impaired visuoperceptual function in the misidentification subtype

“…It is therefore possible that early Lewy body pathology is mediating the association between the misidentification subtype and tests of visual attention/visuoperceptual function in the patients studied. Against this is the absence of the broader deficits in visuospatial and visuoperceptual function that are typically observed in DLB (Cagnin et al ., 2013) and the fact that UPDRS scores were comparable with those previously reported in AD (Cagnin et al ., 2013). …”

“…A more detailed chronology of the illness, including time to onset of psychotic phenomena, will be required in future studies. We cannot completely rule out the possibility that patients with the misidentification subtype in the current sample represent early, undiagnosed cases of DLB, given the occurrence of visual hallucinations and misidentifications at a relatively mild stage of disease (Ferman et al ., 2013), the fact that impaired VOSP performance has been previously reported in DLB (Cagnin et al ., 2013) and the trend towards higher UPDRS scores in the psychotic group. It is therefore possible that early Lewy body pathology is mediating the association between the misidentification subtype and tests of visual attention/visuoperceptual function in the patients studied.…”

Drawing Disorders in Alzheimer’s Disease and Other Forms of Dementia

“…1). According to several authors [21,88,125,126,201,202], the CDT is able to distinguish different severity levels and clinical forms of dementia, but other authors reported contrasting findings with respect to both issues [65,123,128,131,158]. These deceiving results are probably due to two main factors.…”

“…However, several studies employing CDT did not report significant differences in overall total score in LBD and AD patients [156,157], likely because of the complexity of the task (see Fig. 1), although at least two studies reported significantly lower overall scores in LBD versus AD patients [158,159]. A SPECT study showed that LBD patients with defective performance on CDT presented more marked hypoperfusion in a frontal-subcortical network, involving frontal eye fields and the thalamus, with respect to LBD patients with normal CDT scores [160].…”

“…No 2-year decline in FTD Comparison AD-LBD Nervi [152] Figure copying LBD worse than AD Crowell [153] Figure copying LBD worse than AD Tiraboschi [154] Figure copying LBD worse than AD; no differences in pentagon copying Cahn-Wiener [156] CDT No differences in overall score, but more conceptual and planning errors in LBD Hamilton [157] Clock copying No differences, but lower scores predicted steeper decline in LBD Cagnin [158] CDT LBD worse than AD Palmqvist [159] CDT, cube copying LBD worse than AD Gnanalingham [162] CDT, clock copying No difference in CDT; LBD worse than AD in clock copying Ala [164] Pentagon copying LBD worse than AD Cormack [165] Pentagon copying LBD worse than AD Connor [166] Pentagon copying No difference Caffarra [167] Figure copying, No difference in figure copying, pentagon copying worse scores in LBD on an analytic scoring system for pentagon copying AD, Alzheimer's disease; VaD, vascular dementia; sVaD, subcortical VaD; FTD, frontotemporal dementia; bvFTD, behavioral variant of FTD; PA, progressive aphasia; LBD, Lewy body dementia; CDT, Clock drawing test; ROCF, copy of Rey's complex figure. Reference numbering follows the text.…”