BACKGROUND Simultanagnosia is a neurological disorder that impairs an individual's ability to perceive more than one object at a time visually.While the individual may acknowledge the presence of multiple objects ...BACKGROUND Simultanagnosia is a neurological disorder that impairs an individual's ability to perceive more than one object at a time visually.While the individual may acknowledge the presence of multiple objects in his field of view,he cannot generally summarize the overall percept.CASE SUMMARY We describe a case of simultanagnosia in Posterior Cortical Atrophy,evidenced by the Ishihara color test.A 54-year-old woman complained of reading problems despite normal visual acuity and a structural eye exam.The patient failed to identify any of the Ishihara color plates in either eye despite adequate naming of colors.Automated visual field testing showed a homonymous hemianopia.Structural and functional neuroimaging and cerebrospinal fluid analysis were consistent with posterior cortical atrophy.CONCLUSION Simultanagnosia can be tested with the Ishihara pseudoisochromatic plates because the recognition of embedded number patterns in the test requires appreciation of a collection of individual stimuli.展开更多
Posterior cortical atrophy(PCA)is a rare neurodegene-rative condition characterized by progressive visual-perceptual deficits.Although the neurocognitive profile of PCA is a growing and relatively well-established fie...Posterior cortical atrophy(PCA)is a rare neurodegene-rative condition characterized by progressive visual-perceptual deficits.Although the neurocognitive profile of PCA is a growing and relatively well-established field,non-pharmacological care remains understudied and to be widely established in clinical practice.In the present work we review the available literature on non-pharmacological approaches for PCA,such as cognitive rehabilitation including individual cognitive exercises and compensatory techniques to improve autonomy in daily life,and psycho-education aiming to inform people with PCA about the nature of their visual deficits and limits of cognitive rehabilitation.The reviewed studies represented a total of 7 patients.There is a scarcity of the number of studies,and mostly consisting of case studies.Results suggest non-pharmacological intervention to be a potentially beneficial approach for the partial compensation of deficits,improvement of daily functionality and improvement of quality of life.Clinical implications and future directions are also highlighted for the advancement of the field,in order to clarify the possible role of non-pharmacological interventions,and its extent,in PCA.展开更多
Potential link between preeclampsia（PE）and posterior cortical atrophy（PCA）：PCA is a neurodegenerative disorder affecting the parietal,occipital,and occipital-temporal brain regions,often manifesting as a decline ...Potential link between preeclampsia（PE）and posterior cortical atrophy（PCA）：PCA is a neurodegenerative disorder affecting the parietal,occipital,and occipital-temporal brain regions,often manifesting as a decline in visual processing and perception skills in affected individuals.展开更多
Rarer dementias are associated with atypical symptoms and younger onset,which result in a higher burden of care.We provide a review of the global literature on longitudinal decline in activities of daily living(ADLs)i...Rarer dementias are associated with atypical symptoms and younger onset,which result in a higher burden of care.We provide a review of the global literature on longitudinal decline in activities of daily living(ADLs)in dementias that account for less than 10%of dementia diagnoses.Published studies were identified through searches conducted in Medical Literature Analysis and Retrieval System Online(MEDLINE),Excerpta Medica Database(Embase),Excerpta Medica Care(Emcare),PsycINFO,and Cumulative Index in Nursing and Allied Health Literature(CINAHL).The search criteria included terms related to‘rarer dementias’,‘activities of daily living’and‘longitudinal or cross-sectional studies’following a predefined protocol registered.Studies were screened,and those that met the criteria were citation searched.Quality assessments were performed,and relevant data were extracted.20 articles were selected,of which 19 focused on dementias within the frontotemporal dementia/primary progressive aphasia spectrum,while one addressed posterior cortical atrophy.Four studies were cross-sectional and 16 studies were longitudinal,with a median duration of 2.2 years.The Disability Assessment for Dementia was used to measure decline in 8 of the 20 studies.The varied sequences of ADL decline reported in the literature reflect variation in diagnostic specificity between studies and within-syndrome heterogeneity.Most studies used Alzheimer’s disease staging scales to measure decline,which cannot capture variant-specific symptoms.To enhance care provision in dementia,ADL scales could be deployed postdiagnosis to aid treatment and planning.This necessitates staging scales that are variant-specific and span the disease course from diagnosis to end of life.展开更多
Background Increased neurofilament levels in biofluids are commonly used as a proxy for neurodegeneration in several neurodegenerative disorders.In this study,we aimed to investigate the distribution of neurofilaments...Background Increased neurofilament levels in biofluids are commonly used as a proxy for neurodegeneration in several neurodegenerative disorders.In this study,we aimed to investigate the distribution of neurofilaments in the cerebral cortex of Parkinson’s disease(PD),PD with dementia(PDD)and dementia with Lewy bodies(DLB)donors,and its association with pathology load and MRI measures of atrophy and diffusivity.Methods Using a within-subject post-mortem MRI-pathology approach,we included 9 PD,12 PDD/DLB and 18 age-matched control donors.Cortical thickness and mean diffusivity(MD)metrics were extracted respectively from 3DT1 and DTI at 3T in-situ MRI.After autopsy,pathological hallmarks(pSer129-αSyn,p-tau and amyloid-βload)together with neurofilament light-chain(NfL)and phosphorylated-neurofilament medium-and heavy-chain(p-NfM/H)immunoreactivity were quantified in seven cortical regions,and studied in detail with confocal-laser scanning microscopy.The correlations between MRI and pathological measures were studied using linear mixed models.Results Compared to controls,p-NfM/H immunoreactivity was increased in all cortical regions in PD and PDD/DLB,whereas NfL immunoreactivity was increased in the parahippocampal and entorhinal cortex in PDD/DLB.NfL-positive neurons showed degenerative morphological features and axonal fragmentation.The increased p-NfM/H correlated with p-tau load,and NfL correlated with pSer129-αSyn but more strongly with p-tau load in PDD/DLB.Lastly,neuro-filament immunoreactivity correlated with cortical thinning in PD and with increased cortical MD in PDD/DLB.Conclusions Taken together,increased neurofilament immunoreactivity suggests underlying axonal injury and neurofilament accumulation in morphologically altered neurons with increased pathological burden.Importantly,we demonstrate that such neurofilament markers at least partly explain MRI measures that are associated with the neurodegenerative process.展开更多
文摘BACKGROUND Simultanagnosia is a neurological disorder that impairs an individual's ability to perceive more than one object at a time visually.While the individual may acknowledge the presence of multiple objects in his field of view,he cannot generally summarize the overall percept.CASE SUMMARY We describe a case of simultanagnosia in Posterior Cortical Atrophy,evidenced by the Ishihara color test.A 54-year-old woman complained of reading problems despite normal visual acuity and a structural eye exam.The patient failed to identify any of the Ishihara color plates in either eye despite adequate naming of colors.Automated visual field testing showed a homonymous hemianopia.Structural and functional neuroimaging and cerebrospinal fluid analysis were consistent with posterior cortical atrophy.CONCLUSION Simultanagnosia can be tested with the Ishihara pseudoisochromatic plates because the recognition of embedded number patterns in the test requires appreciation of a collection of individual stimuli.
文摘Posterior cortical atrophy(PCA)is a rare neurodegene-rative condition characterized by progressive visual-perceptual deficits.Although the neurocognitive profile of PCA is a growing and relatively well-established field,non-pharmacological care remains understudied and to be widely established in clinical practice.In the present work we review the available literature on non-pharmacological approaches for PCA,such as cognitive rehabilitation including individual cognitive exercises and compensatory techniques to improve autonomy in daily life,and psycho-education aiming to inform people with PCA about the nature of their visual deficits and limits of cognitive rehabilitation.The reviewed studies represented a total of 7 patients.There is a scarcity of the number of studies,and mostly consisting of case studies.Results suggest non-pharmacological intervention to be a potentially beneficial approach for the partial compensation of deficits,improvement of daily functionality and improvement of quality of life.Clinical implications and future directions are also highlighted for the advancement of the field,in order to clarify the possible role of non-pharmacological interventions,and its extent,in PCA.
基金supported in part by the National Institutes of Health funding,No.4R00HL129192(to JPW)
文摘Potential link between preeclampsia（PE）and posterior cortical atrophy（PCA）：PCA is a neurodegenerative disorder affecting the parietal,occipital,and occipital-temporal brain regions,often manifesting as a decline in visual processing and perception skills in affected individuals.
基金supported by UKResearch and Innovation(MR/S03546X/1)National BrainAppeal,Economic and Social ResearchCouncil(ES/S010467/1)+4 种基金Wellcome Trust(221915/Z/20/Z),ESRC(ES/W006014/1)Royal National Institute for Deaf People-Dunhill Medical Trust Pauline Ashley(204841/Z/16/Z,PA23)London Hospitals Biomedical Research Centre(221915/Z/20/Z)Bloomsbury and East London Doctoral Training Partnership(ES/P000592/1)National Institute for Health Research.
文摘Rarer dementias are associated with atypical symptoms and younger onset,which result in a higher burden of care.We provide a review of the global literature on longitudinal decline in activities of daily living(ADLs)in dementias that account for less than 10%of dementia diagnoses.Published studies were identified through searches conducted in Medical Literature Analysis and Retrieval System Online(MEDLINE),Excerpta Medica Database(Embase),Excerpta Medica Care(Emcare),PsycINFO,and Cumulative Index in Nursing and Allied Health Literature(CINAHL).The search criteria included terms related to‘rarer dementias’,‘activities of daily living’and‘longitudinal or cross-sectional studies’following a predefined protocol registered.Studies were screened,and those that met the criteria were citation searched.Quality assessments were performed,and relevant data were extracted.20 articles were selected,of which 19 focused on dementias within the frontotemporal dementia/primary progressive aphasia spectrum,while one addressed posterior cortical atrophy.Four studies were cross-sectional and 16 studies were longitudinal,with a median duration of 2.2 years.The Disability Assessment for Dementia was used to measure decline in 8 of the 20 studies.The varied sequences of ADL decline reported in the literature reflect variation in diagnostic specificity between studies and within-syndrome heterogeneity.Most studies used Alzheimer’s disease staging scales to measure decline,which cannot capture variant-specific symptoms.To enhance care provision in dementia,ADL scales could be deployed postdiagnosis to aid treatment and planning.This necessitates staging scales that are variant-specific and span the disease course from diagnosis to end of life.
基金funded by The Michael J.Fox Foundation(grant#17253)Stichting ParkinsonFonds(grant#1881)supported by the NIHR biomedical research centre at the University College Hospital of London(UCLH).
文摘Background Increased neurofilament levels in biofluids are commonly used as a proxy for neurodegeneration in several neurodegenerative disorders.In this study,we aimed to investigate the distribution of neurofilaments in the cerebral cortex of Parkinson’s disease(PD),PD with dementia(PDD)and dementia with Lewy bodies(DLB)donors,and its association with pathology load and MRI measures of atrophy and diffusivity.Methods Using a within-subject post-mortem MRI-pathology approach,we included 9 PD,12 PDD/DLB and 18 age-matched control donors.Cortical thickness and mean diffusivity(MD)metrics were extracted respectively from 3DT1 and DTI at 3T in-situ MRI.After autopsy,pathological hallmarks(pSer129-αSyn,p-tau and amyloid-βload)together with neurofilament light-chain(NfL)and phosphorylated-neurofilament medium-and heavy-chain(p-NfM/H)immunoreactivity were quantified in seven cortical regions,and studied in detail with confocal-laser scanning microscopy.The correlations between MRI and pathological measures were studied using linear mixed models.Results Compared to controls,p-NfM/H immunoreactivity was increased in all cortical regions in PD and PDD/DLB,whereas NfL immunoreactivity was increased in the parahippocampal and entorhinal cortex in PDD/DLB.NfL-positive neurons showed degenerative morphological features and axonal fragmentation.The increased p-NfM/H correlated with p-tau load,and NfL correlated with pSer129-αSyn but more strongly with p-tau load in PDD/DLB.Lastly,neuro-filament immunoreactivity correlated with cortical thinning in PD and with increased cortical MD in PDD/DLB.Conclusions Taken together,increased neurofilament immunoreactivity suggests underlying axonal injury and neurofilament accumulation in morphologically altered neurons with increased pathological burden.Importantly,we demonstrate that such neurofilament markers at least partly explain MRI measures that are associated with the neurodegenerative process.
