Validity of clinical criteria for the diagnosis of dementia with Lewy bodies

OBJECTIVE: To assess the clinical validity of clinical diagnostic criteria for dementia with Lewy bodies (DLB). METHODS: We assessed the sensitivity, specificity, and positive and negative predictive values of the clinical criteria of the Consortium on dementia with Lewy Bodies (CDLB) in 18 patients with autopsy-proven DLB and in 76 patients with dementia not associated with Lewy bodies, using postmortem diagnosis as a gold standard. RESULTS: CDLB criteria had either high sensitivity or high specificity, but no set of criteria simultaneously provided both high sensitivity and high specificity. Clinical criteria had higher predictive validity in patients with pure DLB than in patients with DLB and AD. Seventy-eight percent of patients with pure DLB had two or more major criteria, compared with 44% of patients with DLB and AD (p<0.02). If the nine patients with DLB and AD were excluded from the DLB group, the CDLB criteria for probable DLB had sensitivity of 78% and specificity of 85%. CDLB criteria for probable DLB (two or more major criteria) distinguished DLB from AD with a sensitivity of 78% and a specificity of 64%. CONCLUSIONS: The proposed CDLB criteria have high negative predictive value and thus do well at excluding patients with DLB. Positive predictive value of 75% can be achieved by a combination of any three major or minor criteria, providing the analysis is confined to patients with mild to moderate dementia. Criteria were most accurate if confined to patients with pure DLB who had mild to moderate dementia.     

Simplified neuropathological diagnosis of dementia with Lewy bodies

Pathological criteria have recently been developed to differentiate those cases where Lewy bodies contribute to the dementing process. We applied consensus criteria to 20 cases with a pathological diagnosis of Alzheimer's disease (all demented) and/or Parkinson's disease (three without dementia) and eight controls. In addition, we applied the criteria to the different cortical layers to determine whether the site of the semiquantification affected the diagnosis. In the parietal lobe, few Lewy bodies were observed, and this region could be excluded. Rare Lewy bodies present in the frontal association cortex in a number of Parkinson's disease cases resulted in their classification as limbic or transitional cases with Lewy bodies. Exclusion of this non-limbic association cortex resulted in many of these cases with rare cortical Lewy bodies being re-classified as having brain stem predominant Lewy bodies, thus improving the diagnostic accuracy of the criteria. Most of these cases were non-demented. No other case was re-classified by excluding these cortical regions from the analysis. Few Lewy bodies were present in cortical layers I and II, and these layers could be excluded from the semiquantitative procedure without change to the overall classification of cases. The occasional presence of possible Lewy bodies in cases with Alzheimer's disease and controls incorrectly classified these cases as having brain stem predominant Lewy body disease, although these cases had no brain stem Lewy bodies. These modifications to the consensus criteria for assessing Lewy body disease (i.e. exclude parietal and frontal lobe, cortical layers I and II, and cases without brain stem Lewy bodies), provide significant time and cost savings for neuropathologists and researchers using this criteria to diagnose and study dementia with Lewy bodies.     

Definition and diagnosis of dementia with Lewy bodies

Significant advances have been made in neuropathologic identification procedures for dementia with Lewy bodies (DLB), but difficulties remain in clinical diagnosis. Consensus criteria state that the core features of DLB are fluctuating cognition with pronounced variation in attention and alertness, recurrent visual hallucinations and spontaneous motor features of parkinsonism. At least two of these features must be present for the diagnosis of probable DLB. Assessments of the validity of the consensus criteria against autopsy generally indicate high specificity but varying sensitivity. More detailed assessments of core diagnostic features or better operationalization, particularly of fluctuating cognition, may help improve the diagnostic guidelines. Greater utilization of some features described as supporting the diagnosis (such as auditory hallucinations) and the potential inclusion of additional symptoms (such as REM sleep behavioral disorder) also may be useful. In addition, the potential role of more detailed neuropsychology and neuroimaging in the diagnostic process needs to be evaluated, although it is important that changes to the diagnostic criteria are based on empirical evidence. Other key issues pertain to the classification of DLB patients with concurrent Alzheimer's disease and the differentiation of DLB and Parkinson's disease dementia based on less than a 1-year history of parkinsonism preceding the dementia.     

Clinical diagnosis of dementia with Lewy bodies in a Japanese dementia registry.

We found 15 patients with dementia with Lewy bodies (DLB) and 232 patients with Alzheimer's disease (AD) among 327 consecutive patients with mild to moderate dementia in a Japanese dementia registry, using the clinical criteria of the Consortium on DLB International Workshop. The percentage of females was significantly lower in DLB than in AD (p < 0.01), while age at examination, Mini-Mental State Examination score and duration of cognitive symptoms were comparable between the two diseases. Eight of the 15 DLB patients (53%) had spontaneous parkinsonism, which was observed in 6 of the 232 AD patients (2.6%). Visual hallucinations were reported by 11 of the 15 DLB patients (73%) and 8 of the 232 AD patients (3.4%). Cognitive fluctuation was positive in 13 of the 15 DLB patients (87%). We found two types of episodic cognitive deterioration: one was characterized by pronounced disturbances of attention and alertness (inattention type), and the other was characterized by marked and bizarre disturbances of orientation in time and places, and misidentification of persons (disorientation type). Systematized delusion was observed in 8 DLB patients, and 5 patients showed neuroleptic sensitivity. Patients with DLB have a unique dementia syndrome even in the stage of mild to moderate cognitive impairments. Further studies are recommended to establish diagnosis, treatment and management.     

Treatment of dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is known for its partial resistance and hypersensitivity to some treatments, but DLB is treatable with cholinesterase inhibitors, sometimes better than in Alzheimer's disease. Cholinesterase inhibitors have a symptomatic effect on cognition and behavior. Nevertheless, new antipsychotics are sometimes also useful to manage psychotic symptoms. Although DLB patients respond less well to levodopa than patients with Parkinson's disease, 75 percent of DLB patients improve with levodopa, which is the best-tolerated dopaminergic agent. Nonpharmacological strategies include speech therapy, physiotherapy, psychotherapy, and educational support groups for care givers.     

Neuroimaging of dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is a relative newcomer to the field of late-life dementia. Although a diversity of imaging methodologies is now available for the study of dementia, these have been applied most often to Alzheimer's disease (AD). Studies on DLB, although fewer, have yielded fascinating and important insights into the underlying pathophysiology of this condition and allowed clinical differentiation of DLB from other dementias. Imaging research on DLB has had significant ramifications in terms of raising the profile of DLB and helping define it as a distinctive and separate disease entity from AD.     

The use of EEG in the diagnosis of dementia with Lewy bodies

Although reports on EEG in dementia with Lewy bodies (DLB) are conflicting, the recent diagnostic guidelines define EEG abnormalities as being supportive for the diagnosis. We examined EEG abnormalities in 18 patients with DLB, 34 patients with Alzheimer's disease (AD) and 36 patients with subjective memory complaints (SMC) using the Grand Total EEG (GTE) score. There was a difference in median GTE score of DLB (11.0), AD (4.8) and SMC (2.5) (p<0.001). Patients with DLB had higher scores than patients with AD. ROC analyses revealed that patients with DLB could be distinguished from those with AD with a sensitivity of 72% and a specificity of 85% at a GTE cut-off of 9.5. The association between GTE and DLB was independent of age, gender, Mini Mental State Examination and medication use. Frontal intermittent rhythmic delta activity (FIRDA) was found in 2.9% of the patients with AD and in 33.3% of the patients with DLB. The GTE is a simple EEG scoring method that can be helpful in the differential diagnosis between DLB and AD with good sensitivity and specificity.     

Lewy bodies and dementia

The discovery of widely distributed Lewy bodies (LBs) in the brains of patients with dementia has stimulated much clinical and pathologic inquiry. This clinico-pathologic syndrome is now referred to as dementia with Lewy bodies (DLB). Diagnostic criteria for DLB proposed at a workshop in 1995 are receiving detailed scrutiny. The criteria are complex to apply, and appear to have high specificity, but variable sensitivity. Neuropathologic studies have been aided by the development of probes against a-synuclein, a key component of LBs. Widespread LBs in limbic or cortical areas contribute to dementia. Pharmacologic management of cognitive and behavioral symptoms in patients with DLB is being explored. There is evidence that cholinesterase inhibitors may have beneficial effects.     

Research evaluation and prospective diagnosis of dementia with Lewy bodies.

OBJECTIVE: To evaluate the relative merits of recently developed criteria for dementia with Lewy bodies (DLBs) in a longitudinal study of dementia. DESIGN: The diagnosis of DLBs was used in combination with other clinical diagnosis. Patients were classified primarily based on the NINCDS-ADRDA (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association) clinical criteria for probable or possible Alzheimer disease, or with other disease process that can cause dementia (eg, Parkinson disease), and secondarily according to the consensus guidelines for DLBs. This "double" clinical diagnosis was implemented to capture different pathological entities. The neuropathological diagnosis of Lewy bodies was made with monoclonal antibodies against alpha-synuclein. SETTING: Multidisciplinary research clinic. RESULTS: Prospective application of the consensus guidelines for DLBs from January 1, 1997, to September 29, 2000, identified 11 patients having the diagnosis of probable DLBs and 35 having possible DLBs. The diagnosis of probable or possible DLBs was associated with probable Alzheimer disease in 34 patients, with possible Alzheimer disease in 5 patients, with Parkinson disease in 2 patients, and with other disease processes in 2 patients. Three patients were diagnosed as having probable DLBs alone. An autopsy was performed in 26 of the cases who were clinically examined during the study period. Cortical Lewy bodies were identified in 13 cases; 4 had had premortem diagnosis of DLBs (sensitivity, 30.7%; specificity, 100%). CONCLUSIONS: The prospective validation of the clinical criteria for DLBs showed poor accuracy in this series. We believe that current criteria for DLBs are useful when DLBs occur in isolation, but have low sensitivity when Lewy bodies coexist with the pathological abnormalities of Alzheimer disease.     

Microbleeds in dementia with Lewy bodies

Journal of Neurology - Microbleeds are associated with the development of dementia in older people and are common in Alzheimer’s disease (AD). Their prevalence and clinical importance in...     

Validation of the neuropathologic criteria of the third consortium for dementia with Lewy bodies for prospectively diagnosed cases

There is limited information on the validity of the pathologic criteria of the Third Consortium on Dementia with Lewy bodies (CDLB), and none are based on prospectively diagnosed cases. In this study, the core clinical features of dementia with Lewy bodies (DLB) and the suggestive clinical feature of rapid eye movement sleep behavior disorder were assessed using a battery of standardized clinical instruments in 76 patients with the clinical diagnosis of either DLB or Alzheimer disease. At autopsy, 29 patients had high-likelihood, 17 had intermediate-likelihood, and 6 had low-likelihood DLB pathology. The frequency of core clinical features and the accuracy of the clinical diagnosis of probable DLB were significantly greater in high-likelihood than in low-likelihood cases. This is consistent with the concept that the DLB clinical syndrome is directly related to Lewy body pathology and inversely related to Alzheimer pathology. Thus, the Third Consortium on DLB neuropathologic criteria scheme performed reasonably well and are useful for estimating the likelihood of the premortem DLB syndrome based on postmortem findings. In view of differences in the frequency of clinically probable DLB in cases with Braak neurofibrillary tangle stages V (90%) and VI (20%) and diffuse cortical Lewy bodies, a possible modification of the scheme is to consider cases with neurofibrillary tangle stage VI to be low-likelihood DLB.     

Pharmacologic therapy of dementia with Lewy bodies

As a clinicopathologically defined entity, dementia with Lewy bodies (DLB) has overlapping features of Alzheimer's disease (AD) and Parkinson's disease (PD). Analogous characteristics of DLB offer a provisional rationale for pharmacologic therapy based on remediating cholinergic and dopaminergic deficits, respectively. However, the distinct clinical manifestations and pathophysiologic substrates of DLB pose unique therapeutic opportunities and challenges. More severe cholinergic deficits in DLB relative to AD support clinical evidence that cholinergic therapy may be particularly beneficial in DLB patients. In contrast, DLB patients are generally more sensitive to the adverse effects of antipsychotic agents, warranting caution in treating visual hallucinations and other psychotic symptoms. Similarly, parkinsonian motor signs in DLB, often manifest as rigidity and bradykinesia, may be less amenable to dopaminergic therapies than in PD. Increasing recognition of DLB as a common form of dementia in the elderly underscores the need for large-scale, placebo-controlled therapeutic trials.     

Diagnostic accuracy of dementia with Lewy bodies

BACKGROUND: Diagnostic criteria for dementia with Lewy bodies (DLB) are still evolving. No data exist on prospective differentiation of DLB and Alzheimer disease (AD). OBJECTIVE: To examine the clinician's diagnostic accuracy for DLB and analyze factors contributing to false-positive DLB diagnoses. METHODS: A prospective series of 10 patients with clinically diagnosed DLB who came to autopsy was compared with 32 autopsy-confirmed cases of DLB (27 Lewy body variant, 5 diffuse Lewy body disease) and 20 autopsy-confirmed cases of AD (matched on age, sex, education, and initial Mini-Mental State Examination score) with regard to distinguishing and/or confounding clinical features. RESULTS: The clinical diagnostic accuracy for DLB was 50%, with 5 of the 10 patients clinically presumed to have DLB confirmed at autopsy. Of the 5 misdiagnosed cases, 4 had AD and 1 had progressive supranuclear palsy. The misdiagnosed DLB cases who had pure AD had fewer hallucinations (25%) than those with Lewy body variant (63%) or diffuse Lewy body disease (100%) (P = .048); however, an equal amount of spontaneous (in the absence of neuroleptics) extrapyramidal signs was found. There were no differences among groups with regard to daily fluctuations in cognition or falls. Compared with the AD control group, the misdiagnosed DLB cases with pure AD showed significantly more spontaneous extrapyramidal signs (P< or =.02). CONCLUSIONS: The clinician's diagnostic accuracy for DLB was poor. Early spontaneous extrapyramidal signs in AD were associated with false-positive clinical diagnoses of DLB. The distinction between DLB and AD may be improved by greater emphasis on hallucinations.     

Clinicopathological multiplicity of dementia with Lewy bodies

‘Dementia with Lewy bodies (DLB)’ is a generic clinicopathological concept characterized by progressive dementia and Lewy bodies (LB). We examined 23 autopsied DLB cases clinicopathologically and immunohistochemically. These cases were classified into the neocortical type (10 cases), the limbic type (seven cases), the cerebral type (one case) and the brainstem type (none) according to our pathological criteria, which were based on the regional incidence of LB and the degree of neuronal loss in the substantia nigra. Each subtype of DLB was further divided into the common form and the pure form on the basis of the degree of Alzheimer pathology. The remaining five cases were not classified by our pathological criteria, and were designated ‘the senile dementia of Alzheimer type (SDAT) or Alzheimer's disease (AD) type of DLB with neocortical or limbic LB’. We examined how each subtype was correlated with various clinical features, such as the age of disease onset, the clinical duration, the degree of dementia, and the presence or absence of parkinsonism, fluctuating cognition and visual hallucination. The results of this study indicate that DLB can be clinicopathologically divided into a number of subtypes, that each subtype is preferentially correlated with some clinical feature, and that the neocortical type, common form, is the major type of DLB.     

Neuropsychological profile of dementia with Lewy bodies

Dementia with Lewy bodies (DLB) accounts for 10–25% of all dementia cases in clinical populations and is considered to be the second most common degenerative dementia in elderly people after Alzheimer's disease (AD). Dementia with Lewy bodies is characterized by the presence of cognitive, psychiatric, and motor symptoms. Although the neuropsychological profiles of patients with DLB often differ from those of patients with AD, the diagnostic sensitivity, specificity, and predictive values of these profiles remain largely unknown. The present paper reviews the neuropsychological profiling of DLB and attempts the neuropsychological differentiation of DLB from AD.