The accuracy of short clinical rating scales in neuropathologically diagnosed dementia

A systematic review of cognitive and behavioral tools to differentiate behavioral variant frontotemporal dementia from other conditions

The behavioral variant of frontotemporal dementia (bvFTD) is thought to be the commonest clinical presentation of frontotemporal lobar degeneration and is predominantly characterized by changes in behavior. In patients lacking unequivocal biomarker evidence of frontotemporal neurodegeneration, the clinical diagnosis of bvFTD is often unstable. In response, we conducted a systematic review and critical appraisal of cognitive and behavioral tools that have sought to differentiate bvFTD from other conditions. A systematic literature review of PubMed, Scopus, and Web of Science was conducted on December 31, 2023 for cognitive and behavioral tools that differentiated bvFTD from other cohorts. Ninety-six studies were included. The quality appraisal of almost all studies was low and introduced a high risk of bias. The few studies that were of high quality had a prospective study design and recruited patients suspected (but not yet confirmed) to have bvFTD. These studies reported that behavioral tools (e.g., the Frontal Behavioral Inventory) and social cognition tests (e.g., the Ekman's Faces Test) had good test performance in differentiating bvFTD from a broad range of psychiatric and neurological conditions. Importantly, the review highlighted the extreme paucity of studies that have evaluated methods where, in Bayesian terms, there is genuine clinical uncertainty regarding a diagnosis of bvFTD. Most studies used healthy controls of typical Alzheimer's disease as comparators-groups that often have negligible pretest probability of bvFTD. In response, we propose a study design checklist for studies seeking to develop diagnostic algorithms in bvFTD research.

Evaluation of cerebrovascular hemodynamics in vascular dementia patients with a new individual computational fluid dynamics algorithm

BACKGROUND

Cerebral hemodynamic disorders are involved in the occurrence and progression of vascular dementia (VaD), but the methods to detect hemodynamics remainmultifarious and uncertain nowadays. We aim to exploit a computational fluid dynamics (CFD) approach by static and dynamic parameters, which can be used to detect individual cerebrovascular hemodynamics quantitatively.

METHODS

A patient-specific CFD model was constructed with geometrical arteries on the magnetic resonance angiography (MRA) and hemodynamic parameters on ultrasound Doppler, by which, the structural and simulated hemodynamic indexes could be obtained, mainly including the cerebral arterial volume (CAV), the number of visible arterial outlets, the total cerebral blood flow (tCBF) index and the total cerebrovascular resistance (tCVR) index. The hemodynamics were detected in subcortical vascular dementia (SVaD) patients (n = 38) and cognitive normal controls (CNCs; n = 40).

RESULTS

Compared with CNCs, the SVaD patients had reduced outlets, CAV and tCBF index (all P ≤ 0.001), increased volume of white matter hyperintensity (WMH) and tCVR index (both P ≤ 0.01). The fewer outlets (OR = 0.77), higher Hachinski ischemic score (HIS) (OR = 3.65), increased tCVR index (OR = 1.98) and volume of WMH (OR = 1.12) were independently associated with SVaD. All hemodynamic parameters could differentiate the SVaD patinets and CNCs, especially the composite index calculated by outlets, tCVR index and HIS (AUC = 0.943). Fewer outlets and more WMH increased the odds of SVaD, which were partly mediated by the tCBF index (14.4% and 13.0%, respectively).

CONCLUSION

The reduced outlets, higher HIS and tCVR index may be independent risk factors for the SVaD, and a combination of these indexes can differentiate SVaD patients and CNCs reliably. The tCBF index potentially mediates the relationships between hemodynamic indexes and SVaD. Although all simulated indexes only represented the true hemodynamics indirectly, this CFD model can provide patient-specific hemodynamic alterations non-invasively and conveniently.

A long-term longitudinal follow-up of depressed patients treated with ECT with special focus on development of dementia

BACKGROUND

In this study, the long term effects of ECT on patients with depression were investigated through repeated rCBF and EEG measures as well as clinical characteristics over several years. The aim of the investigation was to establish an association with the eventual development of dementia.

METHOD

A cohort of forty-nine patients (21 men and 28 women) with a mean age of 61 years underwent ECT. A subsequent evaluation from medical records and three rating-scales for diagnosis of Alzheimer´s disease (AD), fronto-temporal dementia (FTD), and for vascular dementia (VaD), revealed that 17 patients (8 men and 9 women), had developed dementia. These cases were compared to the 32 patients (13 men and 19 women), who had not developed dementia.

RESULT

Initially, the dementia group, compared to those without dementia, showed a lower hemispheric CBF (left side; p=.029, right side; p=.033), and a lower mean occipital EEG frequency (p=.048). After the first ECT-series, an increase in general disorientation (p=.015), personal disorientation (p=.009), and subsequently, spatial disorientation (p=.021), were seen in the dementia group. There were no differences in the clinical response or remissions after treatment in the groups.

LIMITATIONS

The small sample-size, which did not allow for the comparison of characteristics between different dementias.

CONCLUSION

Depressed older patients who later developed dementia showed lower hemispheric mean level of CBF and EEG mean frequency before ECT and higher personal and spatial disorientation following ECT.

Differential diagnosis of degenerative dementias using basic neuropsychological tests: multivariable logistic regression analysis of 301 patients

BACKGROUND

The validity of neuropsychological tests for the differential diagnosis of degenerative dementias may depend on the clinical context. We constructed a series of logistic models taking into account this factor.

METHODS

We retrospectively analyzed the demographic and neuropsychological data of 301 patients with probable Alzheimer's disease (AD), frontotemporal degeneration (FTLD), or dementia with Lewy bodies (DLB). Nine models were constructed taking into account the diagnostic question (eg, AD vs DLB) and subpopulation (incident vs prevalent).

RESULTS

The AD versus DLB model for all patients, including memory recovery and phonological fluency, was highly accurate (area under the curve = 0.919, sensitivity = 90%, and specificity = 80%). The results were comparable in incident and prevalent cases. The FTLD versus AD and DLB versus FTLD models were both inaccurate.

CONCLUSION

The models constructed from basic neuropsychological variables allowed an accurate differential diagnosis of AD versus DLB but not of FTLD versus AD or DLB.

The Hachinski ischemic scale and cognition: the influence of ethnicity

OBJECTIVE

cardiovascular burden is considered a risk factor for the development of cognitive dysfunction and dementia. While this link is well established in the literature, implementing this work in primary care settings remains a challenge. The goal of this study is to examine the utility of the Hachinski Ischemic Scale (HIS) in identifying cognitive dysfunction and diagnosis of mild cognitive impairment (MCI) in an ethnically diverse sample.

METHODS

data were analysed on 517 participants (211 Mexican Americans and 306 non-Hispanic Whites) recruited from Project FRONTIER, a study of rural health. Neuropsychological measures were utilised to assess for cognitive functioning.

RESULTS

among non-Hispanic Whites, HIS scores were significantly related to poorer performance on tasks of global cognition [B (SE) = -0.13 (0.06), P = 0.02], immediate memory [B (SE) = -0.85 (0.26), P < 0.001], attention [B (SE) = -1.6 (0.36), P < 0.001] and executive functioning [B (SE) = 0.46 (0.12), P < 0.001], and significantly predicted diagnosis of MCI [odds ratio (OR) = 1.4; 95% confidence interval (CI) = 1.2-1.6]. For Mexican Americans, HIS scores were significantly related to immediate memory [B (SE) = -0.78 (0.28), P = 0.01], attention [B (SE) = -0.74 (0.36), P = 0.04] and executive functioning [B (SE) = 0.37 (0.14), P = 0.01]; however, HIS scores were not significantly related to diagnosis of MCI in Mexican Americans (OR = 1.2, 95% CI = 0.96-1.4, P = 0.116).

CONCLUSION

HIS scores were related to cognitive functioning; however, these results differed by ethnicity. It is possible that these findings indicate that vascular factors may increase risk for MCI among non-Hispanic Whites but not for Mexican Americans. These findings are consistent with past research that suggests risk factors for MCI may differ by ethnicity.

Fall-related hip fracture hospitalisations and the prevalence of dementia within older people in New South Wales, Australia: an analysis of linked data

INTRODUCTION

Dementia and fall-related hip fractures both contribute significantly to the burden of illness within elderly populations in Australia and elsewhere. The research presented here uses a large probabilistically linked dataset from NSW, Australia to estimate the prevalence of dementia within hip fracture patients and investigate the impact of dementia on hospitalisation length of stay (LOS) and survival.

METHOD

The cases considered were NSW residents aged 65 years and above who experienced a fall related hip fracture between 1 July 2000 and 30 June 2009. The prevalence of dementia was calculated for the incident hip fracture using two methods to infer dementia status. Cox proportional hazards regression modelling was used to estimate the relative rate of discharge from a hospitalisation episode, and the relative mortality rate of hip fracture patients suffering dementia versus those who were cognitively intact. Additional covariates used in the models included sex, age group at admission, the Charlson Comorbidity Index and separation mode.

RESULTS

Of the 44,143 fall-related incident hip fracture cases considered, between 24% (observed diagnosis) to 29% (inferred diagnosis) of these people had dementia. The median LOS for patients with dementia was shorter than those without dementia, but there was a strong interaction with age. The rate of discharge from the fracture-related hospitalisation episode of the cases with dementia was 40% greater (95% CI 1.4-1.5) than the non-demented group. Similarly, the relative mortality rate of those with dementia was greater (2.4, 95% CI 2.3-2.6) than the non-demented group. Both Cox analyses indicated evidence for main effects of age at admission and comorbidity, as well as interaction effects between age group and dementia status.

CONCLUSION

The use of linked datasets with tens of thousands of cases enables the calculation of precise estimates of various parameters. People with dementia constitute a significant proportion of the total population of elderly hip fracture patients in hospitals (up to 29%). Their mortality rate is greater than those without a diagnosis of dementia and their hospital length of stay is shorter, particularly if they are discharged to a residential aged care facility.

History of depression prior to Alzheimer's disease and vascular dementia verified post-mortem

The aim of this study was to analyze the medical history, with regards to previous remote depression, in patients with neuropathologically verified Alzheimer's disease (AD), vascular dementia (VaD) and mixed AD/VaD. The 201 patients included (115 AD, 44 VaD and 42 mixed AD/VaD) had been referred to the Psychogeriatric/Psychiatric Department, Lund University Hospital, for psychogeriatric investigation and were followed-up with clinical records and detailed information on psychiatric history prior to the onset of dementia. Depression was considered to exist when the patient had consulted a psychiatrist or physician and had been diagnosed with a "depressive episode" or "depression" and when anti-depressants and/or other specific treatments had been prescribed. Twenty patients (10%) had suffered from depression earlier in life well before the onset of dementia. Eight of the 9 AD patients with a previous diagnosis of depression had suffered from only one depressive episode and all had responded well to treatment, with complete recovery. In the VaD group, 8 out of 9 patients suffered two or more depressive episodes and only two recovered completely. Events with a possible significant relationship to depression were seen in 8 of the 9 AD patients but in only 1 of the 9 VaD patients. Psychotic symptoms were more common in VaD than in the AD group. The treatment modality of depression was similar in the groups. In conclusion, a history of depression prior to dementia is more common and more therapy-resistant in VaD than in AD.

A factor analytic approach to symptom patterns in dementia

Previous publications have shown a high diagnostic sensitivity and specificity of three short clinical rating scales for Alzheimer's disease (AD), frontotemporal dementia (FTD), and vascular dementia (VaD) validated against neuropathological (NP) diagnoses. In this study, the aim was to perform an exploratory factor analysis of the items in these clinical rating scales. The study included 190 patients with postmortem diagnoses of AD (n = 74), VaD (n = 33), mixed AD/VaD (n = 31), or FTD (n = 52). The factor analysis produced three strong factors. Factor 1 contained items describing cerebrovascular disease, similar to the Hachinski Ischemic Score. Factor 2 enclosed major clinical characteristics of FTD, and factor 3 showed a striking similarity to the AD scale. A fourth symptom cluster was described by perception and expression of emotions. The factor analyses strongly support the construct validity of the diagnostic rating scales.