Clinicians' ability to diagnose dementia with Lewy bodies is not affected by β-amyloid load

Abstract

Clinicians' ability to diagnose dementia with Lewy bodies is not affected by b-amyloid load ABSTRACT Objective: To investigate whether an increasing load of b-amyloid and/or neuritic plaques influences the phenotype, and thus the clinical diagnostic accuracy, of dementia with Lewy bodies (DLB).Methods: A series of 64 subjects with autopsy-proven DLB was studied. Last diagnosis before death was used to determine the clinical diagnostic accuracy of DLB in relation to Lewy body distribution and extent of Alzheimer b-amyloid and/or neuritic pathology. DLB pathologic diagnosis was made according to consensus criteria, using a-synuclein immunostaining for Lewy body identification. b-Amyloid immunostaining was used for quantifying b-amyloid deposits. The Consortium to Establish a Registry for Alzheimer's Disease criteria and Braak stage were applied for semiquantitative grading of neuritic plaque and neurofibrillary tangle pathology. Conclusions:The likelihood of occurrence of the DLB clinical syndrome is positively related to the extent of Lewy body pathology and negatively related to the severity of Alzheimer neuritic pathology, while b-amyloid load has no effect. Neurology ® 2015;84:496-499

Accuracy of clinical diagnosis of dementia with Lewy bodies: a systematic review and meta-analysis

“…**Including Savica et al 30: 88.3% (95% CI 68% to 99.4%). Luis et al 13, Walker and Walker24, Burton et al 25, Echávarri et al 26 and Tiraboschi et al 27 were not included in the subanalyses based on McKeith 1996-possible or McKeith 1996-probable diagnosis, as they did not distinguish between them.…”

“…Diagnosis of DLB was permitted with an intermediate or high likelihood condition. Indeed, a lower Braak stages improve the clinical sensitivity and specificity of DLB,36 and diagnostic accuracy is positively related to the extent of Lewy body pathology and negatively to the severity of Alzheimer’s neuritic plaque pathology 27. Conversely, in the previous criteria, the only neuropathological requirement for DLB was the presence of Lewy bodies in the brain of a patient with a clinical history of dementia, leading to the inclusion of actual cases of AD as pathologically confirmed DLB and contributing to the view that the clinical criteria had low sensitivity.…”

Lewy body dementias

“…Diagnostic accuracy is higher when α-synuclein pathology is extensive, lower with increasing neuritic plaque pathology, and not affected by amyloid β load. 40 …”

Clinical and imaging correlates of amyloid deposition in dementia with Lewy bodies

“…Previous evidence, particularly from postmortem studies, has suggested that amyloid deposition in DLB may be associated with greater cognitive impairment,30 fewer core features of DLB,31 and greater brain atrophy 32. We hypothesized that amyloid‐positive DLB patients would have a clinical profile with similarities to AD, in particular greater memory impairment.…”

“…In contrast, pathological studies have reported associations between clinical profile and neuritic plaques only,31 or combined amyloid and neurofibrillary tangle pathology 32. Another factor may be that amyloid is an “upstream” factor in a cascade of events leading to neuronal damage and clinical symptoms 33.…”