Triple test, a diagnostic observation, can detect cognitive impairment in older adults

Validity and reliability of the Turkish version of the ALBA screening instrument for Lewy body dementia in older adults

ALBA screening instrument (ASI) has been demonstrated to be an effective, cheap, and noninvasive clinical instrument to screen for Lewy body dementia (LBD). We aimed to determine the validity and reliability of the Turkish version of ASI (ASI-T) in patients with LBD and to investigate the discriminative power of the test in patients with Alzheimer's Disease (AD), LBD, and cognitively healthy older adults (controls). 172 older adults over 60 years of age (43 with LBD, 41 AD, and 88 controls) were included. The sensitivity and specificity of the instrument were determined. A significant difference was found in ASI-T total score between people with LBD versus the controls (t=-9.259; p < 0.001), and versus patients with AD (t = 3.490; p = 0.001). Internal consistency of the ASI-T was good(Cronbach's alpha = 0.81). The cutoff score of 7 showed sensitivity (86%) and specificity (81%) (AUC= 0.888,CI0.95, p < 0.001) compared to controls. Also, compared to AD, it showed sensitivity (86%) and specificity(70%) (AUC = 0.590,CI .95, p < 0.001). Moreover, ASI-T demonstrated a significant concurrent validity with MMSE (r = -0.62; p < 0.001) and MoCA (r = -0.54; p = 0.003). In factor analysis, the five subscales accounted for 60% of the total variance. Our findings suggested that the ASI-T is a reliable, valid, and effective instrument for screening LBD. With acceptable psychometric properties, it has the power to distinguish patients with LBD from controls or those with AD.

Validation of the Turkish version of the Lewy body composite risk score

The Lewy Body Composite Risk Score (LBCRS) has been developed to increase the sensitivity and specificity of the diagnosis attributable to Lewy body pathology outside of specialty centers. We aimed to assess the validity and reliability of the Turkish version of the LBCRS in patients with dementia with Lewy Bodies (DLB) and investigate the discriminative power of the test in Turkish patients with Alzheimer's disease (AD) and DLB, and control group. The sample population (n = 512) comprised DLB (n = 113), DLB-Mild Cognitive Impairment (MCI)(n = 12), AD (n = 42), AD-MCI (n = 21), and control group (n = 324). A significant group difference was observed in the Turkish version of the LBCRS scores of the five groups (p < .001). The Cronbach's α value was 0.82 (95% CI: 0.799-0.868). The test-retest reliability score of the scale was r = 0.94 and p < .001. The subscales of the LBCRS (motor and nonmotor subdomains of the disease) were determined to explain 65.961% of the total variance with an eigenvalue >1. In patients with DLB, the cutoff score of ≥3 showed sensitivity (92%) and specificity (81%) (area under the curve [AUC] = 0.883, 95% CI: 0.815-0.951), p < .001) compared with the AD. Compared to the control group, the cutoff score of ≥3 showed a sensitivity of 98% and specificity of 97% (AUC = 0.994, 95% CI: 0.989-0.999, p < .001). The Turkish version of LBCRS permits accurate diagnosis of DLB with high sensitivity and specificity. Also, it can be useful to inform the caregivers regarding the course of the disease during the follow-up.

"Don't know" sign: description and evaluation of its diagnostic accuracy for cognitive impairment

OBJECTIVES

Patients in neurology clinics are sometimes not aware of the reason for the consultation, and we have called this circumstance the "Don't know" sign (DKS). Our objective was to define this new sign and its modalities and to evaluate its prevalence and its diagnostic accuracy for cognitive impairment (CI) in comparison to other observation-based signs.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional prospective study included all new outpatients evaluated by the authors at neurology consultation.

MEASUREMENTS

We recorded observation-based signs. The Global Deterioration Scale (GDS) was used to assess the cognitive status of patients, based on clinical history, caregiver interview, and cognitive test results. We analyzed the prevalence and the diagnostic accuracy for CI of DKS, "head turning sign," "attending with," verbal repetition, and combinations, calculating sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

We enrolled 673 consecutive patients (62% female) with a mean ± SD age of 59.3 ± 20.2 years. DKS was positive in 94 patients (14%) and was strongly associated with GDS score. DKS had a Se of 0.41, Sp of 0.98, PPV of 0.89, and NPV of 0.79 for CI diagnosis. The presence of at least two positive observation signs yielded a Se of 0.50, Sp of 0.97, PPV of 0.86, and NPV of 0.81.

CONCLUSIONS

DKS is frequently observed in neurology outpatients. It has low sensitivity but high specificity and PPV for CI diagnosis. It does not require additional consultation time, and its use can be recommended in combination with other observation-based signs.

The applause sign in elderly patients with idiopathic normal pressure hydrocephalus

Applause sign (AS) was shown to be an indicator of frontal subcortical dysfunction in many neurodegenerative diseases. Idiopathic normal pressure hydrocephalus (INPH) is one of those in which frontosubcortical disconnection can be displayed. We aimed to examine the presence of AS in the elderly patients with INPH and its possible diagnostic role in the frontal dysfunction commonly seen in the disease. Sixty-six patients diagnosed with probable INPH, 32 with behavioral variant of frontotemporal dementia (bvFTD) and 325 healthy elderly subjects were included in this cross-sectional and retrospective study. AS was evaluated with the clapping test. Patients with INPH were further assessed with frontal assessment battery (FAB), Stroop test, verbal fluency test and clock drawing test (CDT). The concentration of total amyloid-β 42 (Aβ42), Aβ40, total (t) tau and phosphorylated (p)-tau proteins were also measured in the cerebrospinal fluid (CSF). AS was observed in all groups (40% in bvFTD, 28.8% in INPH, 1.2% in controls, respectively). It was significantly more frequent in patients with bvFTD and INPH as compared to the controls (p < 0.001, for each). The frequency was similar in the patients with bvFTD and INPH (p = 0.802). Significant differences were found between the AS(+) and (-) INPH patients with regards to FAB, Stroop test-errors and verbal fluency test, except for the CSF proteins. AS can be used as a simple, useful and rapid clinical test that investigates executive dysfunction in elderly patients with INPH in both inpatient and outpatient settings.

Diagnosis of Dementia and Cognitive Impairment

In this special issue of Diagnostics, expert contributors have produced up-to-date research studies and reviews on various topics related to the diagnosis of dementia and cognitive impairment. The methods of the assessments discussed extend from simple neurological signs, which may be elicited in the clinical encounter, through cognitive screening instruments, to sophisticated analyses of neuroimaging and cerebrospinal fluid biomarkers of disease. It is hoped that these various methods may facilitate earlier diagnosis of dementia and its subtypes, and provide differential diagnosis of depression and functional cognitive disorders, as a prelude to meaningful interventions.

Triple Test Plus Rapid Cognitive Screening Test: A Combination of Clinical Signs and A Tool for Cognitive Assessment in Older Adults

Less time-consuming, easy-to-apply and more reliable cognitive screening tests are essential for use in primary care. The aim of this study was to investigate the diagnostic value of the Turkish version of the Rapid Cognitive Screen (RCS-T) and Triple Test individually and the combination of RCS-T with each sign and Triple Test to screen elderly patients for cognitive impairment (CI). A total of 357 outpatients aged 60 or older, who underwent comprehensive geriatric assessment, were included in the study. Presence or absence of attended alone sign (AAS), head-turning sign, and applause sign was investigated. The mean age of the patients was 74.29 ± 7.46. Of those, 61 patients (28 men, 33 women) had Alzheimer’s disease (AD), 59 patients had mild cognitive impairment (MCI) (29 men, 30 women), and 237 (80 men, 157 women) were cognitively robust. The sensitivity of the combination of RCS-T and negative for AAS for CI, AD and MCI is 0.79, 0.86 and 0.61, respectively; the specificity was 0.92, 0.93 and 0.92, respectively; and the positive and negative predictive values revealed good diagnostic accuracy. The combination of RCS-T and negative for AAS is a simple, effective and rapid way to identify possible CI in older adults.

The AD8 (Dementia Screening Interview) is a valid and reliable screening scale not only for dementia but also for mild cognitive impairment in the Turkish geriatric outpatients

ABSTRACTIntroduction:There is still a need for short, practical, and daily-appropriate scales to distinguish between normal cognitive aging, mild cognitive impairment (MCI), or dementia for patients with memory complaints. This study aimed to determine validity and reliability of AD8 (Dementia Screening Interview) to detect both MCI and dementia in Turkish geriatric outpatients.

METHODS

Comprehensive geriatric assessment was performed in 334 patients, who attended with their informants to the geriatric outpatient clinic for memory complaints. In addition to the AD8, they were screened using Clinical Dementia Rating scale (CDR) and Mini-Mental State Examination. The diagnosis of dementia and MCI was made according to the Diagnostic and Statistical Manual of Mental Disorders - fifth edition (DSM-5) criteria.

RESULTS

The mean age of the patients was 74.5±8.5. Of them, 156 were considered as non-cognitive impairment, 60 as MCI, and 118 as dementia. Cronbach's α value of the AD8 was 0.928. The total AD8 scores were found to be negatively correlated with the MMSE scores (r = -0.801), and positively correlated with CDR score (r = 0.879) (p &lt; 0.001, for each). The area under the receiver-operating characteristics curve was 0.979 for cognitive impairment, and 0.999 for dementia. We found that AD8 can show dementia and MCI when the cut-off values are ≥5 and 3-4, respectively, with a sensitivity of 100% and 81.67% and specificity of 96.3% and 93.59%.

CONCLUSION

AD8 is one of the fast, simple, and sensitive screening methods for detecting both minor and major cognitive impairments. With regard to these features, it can be used in older adults attending the primary care settings with memory complaints.

Validity and Reliability of Rapid Cognitive Screening Test for Turkish Older Adults

OBJECTIVES

Practical cognitive screening tests, brief and easy-to-administer are needed for primary care. The Rapid Cognitive Screen (RCS) is one of the cognitive screening tests used. The present study aimed to establish the validity and reliability of the Turkish version of RCS (RCS-T) in patients with impaired cognitive status.

DESIGN

Prospective validation study.

SETTING AND PARTICIPANTS

Total 323 outpatients aged 60 or older, who were performed comprehensive geriatric assessment, were included in the study.

MEASUREMENTS

Patients were screened by RCS-T, Turkish version of Saint Louis University Mental Status Examination (SLUMS-T), Mini-Mental State Examination (MMSE) and clock drawing test for cognitive impairment (CI).

RESULTS

The mean age of the patients was 72.2±7.4. Out of the patients, 217 were considered as cognitively intact, 54 as mild cognitive impairment (MCI), and 52 as Alzheimer's disease (AD). Cronbach's alpha value of the RCS-T was 0.674 for AD and 0.713 for CI. The total RCS-T scores were positively correlated with MMSE and SLUMS-T scores (r = 0.647 and r = 0.864, respectively) (p < .001, for each). The area under the receiver-operating characteristics curve (95% confidence interval) was 0.96 for AD, 0.92 for CI and 0.856 for MCI. The sensitivity and specificity for RCS-T for cut-off point of 6 and 4 were 85.85 (%) and 87.56 (%) for CI and 84.62 (%) and 91.14 (%) for AD, respectively.

CONCLUSIONS

In a bedside consultation and primary care practice, RCS-T, a simple, quick and sensitive tool for screening CI, seems to be a useful screening test for older patients with CI.

Factors affecting sensitivity and specificity of head-turning sign in the studies

We read with interest the comment by Williamson and Larner on our recent study titled "Attended With and Head-Turning Sign can be clinical markers of cognitive impairment in older adults" (Soysal et al., 2017). After the authors read the study, they re-examined their data according to the presence of Attended With (AW) and Head-Turning Sign (HTS), and compared their results with ours (Larner, 2014). Then, they found that while the sensitivity, specificity, positive predictive value, and negative predictive value of AW in detecting cognitive impairment were similar to ours, HTS had lower sensitivity (80.95% vs. 65.0%) and higher specificity (64.7% vs. 95.0%) than our results (Larner, 2014; Soysal et al., 2017). We think that some methodological and cultural differences may explain these discrepancies between the two.

Number Needed to Diagnose, Predict, or Misdiagnose: Useful Metrics for Non-Canonical Signs of Cognitive Status?

Background/Aims

“Number needed to” metrics may hold more intuitive appeal for clinicians than standard diagnostic accuracy measures. The aim of this study was to calculate “number needed to diagnose” (NND), “number needed to predict” (NNP), and “number needed to misdiagnose” (NNM) for neurological signs of possible value in assessing cognitive status.

Methods

Data sets from pragmatic diagnostic accuracy studies examining easily observed and dichotomised neurological signs (“attended alone” sign, “attended with” sign, head turning sign, applause sign, la maladie du petit papier) were analysed to calculate the NND, NNP, and NNM.

Results

All measures of discrimination showed broad ranges. The range of NND and NNP suggested that these signs were, with a single exception, of value for correctly diagnosing or predicting cognitive status (presence or absence of cognitive impairment) when between 2 and 4 patients were examined. However, NNM showed similar values (range 1–5 patients) suggesting risk of misdiagnosis.

Conclusion

NND, NNP, and NNM may be useful, intuitive, metrics in assessing the utility of diagnostic tests in day-to-day clinical practice. A ratio of NNM to either NND or NNP, termed the likelihood to diagnose or misdiagnose, may clarify the utility or inutility of diagnostic tests.