Post-stroke Cognitive Impairment and Dementia
Condition: Stroke; Cognitive Disorders; Behavioral Disorders
MeSH terms: Stroke; Dementia; Cognitive Dysfunction; Cognition Disorders
Study type: Interventional

Summary: 
      Projections from epidemiological studies suggest that, among the Western adult population,
      one in three will present a cerebrovascular accident (stroke), severe cognitive disorders, or
      both. To better diagnose the Vascular Cognitive Impairment, new standards were developed by a
      North America working group which are under validation. It is essential to adapt these
      standard for French-speaking population, and especially to define cutoff scores of the
      cognitive battery to determine cognitive deficit.

      The investigators propose a study coordinated by the University-Hospital of Amiens for french
      speaking centers. This study will investigate this battery with 906 controls to define the
      standards and 302 stroke affected patients to define the frequency and cognitive mechanisms.
      This step is essential for people to benefit from these new standards.
    

Detailed description: 
      -  Context In western countries, one in three subjects will experience a stroke, dementia
           or both. Recent studies have shown the major role of vascular risk factors and stroke in
           cognitive disorders and dementia. Poststroke cognitive and behavioral disorders are
           characterized by the prominence of action slowing, executive function disorders and
           apathy. They are due to vascular lesions or to associated pathology, mainly Alzheimer's
           disease. In order to determine diagnosis criteria of Vascular Cognitive Impairment, it
           is necessary to develop a standardized assessment of post-stroke cognitive and
           behavioral disorders (Hachinski et al Stroke 2006; 37; 2220-2241). For this purpose, the
           NINDS (National Institute of Neurological Disorders and Stroke

           ) and the Canadian Stroke Network have jointly developed a specific standardized battery
           which is currently under validation. Its use in France requires first a normalization of
           some tests in French speaking healthy controls. This study is supported by the SFNV
           (Société Française NeuroVasculaire) and GRECO (Groupe de Réflexion sur les Evaluations
           Cognitives).

        -  Primary Objectives of the project: to determine the frequency of cognitive and
           behavioral disorders 6 months post-stroke assessed with this new NINDS-Canadian Stroke
           Network battery Primary endpoints: disorders on cognitive tests and on behavioral and
           depression questionnaires (defined by performance outside normal ranges determined in
           healthy controls);

        -  Population Patients consecutive French-speaking patients with an informant assessed 6
           months post-stroke and free from mental retardation, psychosis, illiteracy, previously
           diagnosed dementia, comorbidity known to impair cognitive abilities, MRI
           contraindication or refusal to participate.

      Controls from the general population not presenting any condition known to impair cognitive
      abilities stratified according to age and schooling levels

        -  Design Prospective multicenter study comparing performance of patients and controls
           Sample size: the frequencies of cognitive and behavioral disorders are considered as
           significantly different if the null hypothesis (lack of difference between groups at the
           0.05 quantile) is rejected. Considering that each patient is matched with 3 controls, it
           will be necessary to evaluate 302 patients with the battery 6 months poststroke and 906
           controls to detect a difference between groups of at least 5% with α risk =0.05 and
           power= 80%. In addition, the inclusion of 302 patients allows to determine the frequency
           of impaired patients with a confidence interval CI95% ≤12%.

        -  Feasibility: based on a previous similar study, 50 stroke patients (range 40-60) and 150
           controls (range: 100-200) will be included per year in the University Hospital of
           Amiens. Thus 10 centers with similar inclusion rates will be able to include 302
           patients and 906 controls within 6 years.

        -  Secondary objectives: (1) to determine the frequency of poststroke dementia; (2) to
           determine the frequency of cognitive disorders on screening tests; (3) to examine
           correlations between cerebral MRI and cognitive impairment; (4) to determine
           correlations between cognitive disorders and activities of daily living.

      Secondary endpoints: (1) dementia (DSMIV and NINDS-AIREN criteria ;National Institute of
      Neurological Disorders and Stroke and the Association Internationale pour la Recherche et
      l'Enseignement en Neurosciences ); (2) screening tests (MiniMental Status Examination,
      Montreal Cognitive Assessment);(3) MRI abnormalities (cerebral atrophy, white matter
      abnormalities, stroke type, stroke volume and location) using 3D T1-weighted (axial
      bicommissural plane), T2-weighted (coronal plan), FLAIR, gradient-echo, diffusion-weighted
      (with calculation of the apparent diffusion coefficient) performed at 6 months post-stroke at
      the same time than the cognitive assessment; (4) disability in activities of daily living
      (Rankin scale, Barthel index, Instrumental Activities of Daily Living).
    

Intervention name(s): French adaptation of NINDS-Canadian Stroke Network battery
Intervention type(s): Behavioral
Intervention description(s): clinical: post-stroke neurological follow-up assessment
neuropsychological: comprising the NINDS-Canadian Stroke Network neuropsychological battery
MRI
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Dementia; Alzheimer disease; stroke; cognitive impairment