Clinical evaluation of the ICD-10 criteria for vascular dementia

Accuracy of the Brief Cognitive Screening Battery for diagnosing Alzheimer's disease defined by cerebrospinal fluid biomarkers and AT(N) classification: a case-control study

BACKGROUND

Validation of cognitive instruments for detection of Alzheimer's disease (AD) based on correlation with diagnostic biomarkers allows more reliable identification of the disease.

OBJECTIVES

To investigate the accuracy of the Brief Cognitive Screening Battery (BCSB) in the differential diagnosis between AD, non-AD cognitive impairment (both defined by cerebrospinal fluid [CSF] biomarkers) and healthy cognition, and to correlate CSF biomarker results with cognitive performance.

METHODS

Overall, 117 individuals were evaluated: 45 patients with mild cognitive impairment (MCI) or mild dementia within the AD continuum defined by the AT(N) classification [A+T+/-(N)+/]; 27 non-AD patients with MCI or mild dementia [A-T+/-(N)+/-]; and 45 cognitively healthy individuals without CSF biomarker results. All participants underwent evaluation using the BCSB.

RESULTS

The total BCSB and delayed recall (DR) scores of the BCSB memory test showed high diagnostic accuracy, as indicated by areas under the ROC curve (AUC): 0.89 and 0.87, respectively, for discrimination between AD and non-AD versus cognitively healthy controls. Similarly, total BCSB and DR displayed high accuracy (AUC-ROC curves of 0.89 and 0.91, respectively) for differentiation between AD and controls. BCSB tests displayed low accuracy for differentiation between AD and non-AD. The CSF levels of biomarkers correlated significantly, though weakly, with DR.

CONCLUSIONS

Total BCSB and DR scores presented good accuracy for differentiation between patients with a biological AD diagnosis and cognitively healthy individuals, but low accuracy for differentiating AD from non-AD patients.

Clinical diagnosis of vascular dementia

Vascular dementia (VaD) is a heterogeneous clinical entity based on various vascular pathophysiological processes underlying the subtypes of cerebrovascular disease (CVD). Several diagnostic criteria are currently being used for the clinical diagnosis of VaD, but they are mostly more than 10 years old and need to be renovated including the use of functional brain imaging methods such as single photon emission computerized tomography (SPECT). There is a limitation in the diagnosis based on the strict dichotomy between AD and VaD, and the concept of "AD with CVD" or "mixed dementia" should be included in the clinical diagnosis of VaD.

Comparison of different clinical criteria (DSM-III, ADDTC, ICD-10, NINDS-AIREN, DSM-IV) for the diagnosis of vascular dementia. National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences

BACKGROUND AND PURPOSE

The criteria for vascular dementia (VaD) include definition of the cognitive syndrome and the vascular cause. Different criteria for dementia identify different frequencies and clusters of patients. In addition, variation in defining the cause and etiology may have an effect. We compared different clinical criteria for VaD in series of patients with poststroke dementia.

METHODS

The study group comprised 107 patients fulfilling the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III) definition for dementia from a cohort of consecutive patients with ischemic stroke who completed a comprehensive neuropsychological test battery and MRI. The mean age (SD) of the patients was 71.4 (7.6) years. The definitions of vascular cause of VaD were those of the DSM-III (1980), Alzheimer's Disease Diagnostic and Treatment Centers (ADDTC; 1992), International Statistical Classification of Diseases, 10th Revision (ICD-10; 1992), National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN; 1993), and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV; 1994).

RESULTS

The number of cases that could be classified as VaD according to the different criteria varied considerably: 36.4% (n=39) by DSM-III, 86.9% (n=93) by ADDTC, 32.7% (n=35) by NINDS-AIREN, 36.4% (n=39) by ICD-10, and 91.6% (n=98) by DSM-IV criteria. The concordance between DSM-III/ICD-10 was perfect (100%; kappa=1.0), between ICD-10/NINDS-AIREN and ADDTC/DSM-IV good to moderate (85.0% and 87. 3%; kappa=0.87 and 0.37, respectively), but otherwise poor between the other criteria. Only 31 patients fulfilled all the criteria for VaD applied. Major discriminating factors between the criteria were requirement of (1) focal neurological signs, (2) unequal distribution of deficits in higher cortical functions, and (3) evidence of relevant CVD based on brain imaging findings.

CONCLUSIONS

Current criteria of VaD identify different frequencies and clusters of patients and are not interchangeable. Optimally, prospective studies with clinicopathological correlation could identify new criteria. Meanwhile, focus on more homogeneous subtypes (eg, small-vessel subcortical VaD) and detailed neuroimaging criteria could improve the diagnostics.

Efficacy and safety of nimodipine in subcortical vascular dementia: a subgroup analysis of the Scandinavian Multi-Infarct Dementia Trial

In Western countries, vascular dementia (VaD) is the most common form of cognitive deterioration after Alzheimer's disease. Therapeutic trials in VaD have so far failed to yield satisfactory results. One explanation of this failure may be the etiological and clinical heterogeneity of the included patients. Patients with subcortical VaD, defined on a clinical and radiological basis, may constitute a more homogeneous group. Thus, we conducted a post-hoc subgroup analysis of the Scandinavian Multi-Infarct Dementia Trial that evaluated the efficacy and safety of oral nimodipine administered for 6 months in 259 patients. The original patients sample was divided on the basis of head CT in those with subcortical VaD (n=92, 45 nimodipine, 47 placebo) and those with multi-infarct dementia (n=167, 83 nimodipine, 84 placebo). While in the total trial population a treatment effect could not be proved, in this subgroup analysis, the subcortical VaD patients treated with nimodipine performed better on the majority of neuropsychological tests and functional scales in comparison with patients on placebo. No trend could be evidenced in the multi-infarct dementia patients. Treatment efficacy was in particular suggested for the Zahlen-Verbindungs-Test, Fuld-Object-Memory Evaluation, Word Fluency, and for the Instrumental Activities of Daily Living scale. The results did not reach statistical significance in this small sample. Our study preliminarily indicates that nimodipine could be effective in patients with small vessel subcortical VaD and supports the rationale for a further controlled and adequately powered trial to test nimodipine in patients with subcortical VaD.

Comparison of different diagnostic criteria for vascular dementia (ADDTC, DSM-IV, ICD-10, NINDS-AIREN)

BACKGROUND AND PURPOSE

Vascular dementia (VD) has been an ill-defined term thus far. Recently detailed criteria for the diagnosis of VD have been proposed (Alzheimer's Disease Diagnostic and Treatment Centers [ADDTC], 1992; Diagnostic and Statistical Manual of Mental Disorders, 4th edition [DSM-IV], 1994; International Classification of Diseases, 10th revision [ICD-10], 1992, 1993; and National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences [NINDS-AIREN], 1993). Until now the clinical feasibility of these diagnostic guidelines has not been evaluated.

METHODS

This study aimed to compare these criteria in an unselected sample of 167 elderly patients (mean age, 72.0 +/- 9.9 years) admitted with probable dementia.

RESULTS

The number of cases that could be classified as VD differed widely between the various diagnostic guidelines. According to DSM-IV criteria, 45 cases were diagnosed as VD. Twenty-one cases fulfilled the ICD-10 research criteria, but only 12 met the NINDS-AIREN criteria for VD. Twenty-three cases were classified as ischemic VD as defined by the ADDTC criteria. The concordance was very poor since only 5 cases met the criteria for VD of all diagnostic guidelines.

CONCLUSIONS

Our results show that the classification according to different diagnostic guidelines yields rather distinct groups of patients. The reasons responsible for these findings are as follows: (1) different criteria for dementia, (2) limitation to ischemic VD in the ADDTC criteria, (3) no further differentiation of VD into subtypes according to CT or MRI findings (DSM-IV), and (4) the multifactorial etiopathology of VD. Major diagnostic difficulties ensue from the very frequent cases with white matter lesions, since their etiology and classification remain widely unknown.