Impact of Physical Activity in Vascular Cognitive Impairment ( AFIVASC )

Vascular cognitive impairment is one of the most frequent causes of cognitive impairment associated with aging. Vascular cognitive impairment includes clinical deficits due to vascular subclinical brain injury, silent lesions or due to clinically overt stroke, and appears frequently associated with Alzheimer disease. Vascular cognitive impairment has a spectrum of manifestations, from mild to extreme manifestation (Vascular Dementia) that represents the second most frequent cause of dementia. There is no approved treatment for vascular cognitive impairment, and pharmacological trials have generated disappointing results. As a result, nowadays, treatment is solely based on the control of vascular risk factors.

Walking is a physical activity recommended for the prevention of coronary disease. Besides, it is a physical activity without additional costs, easily accessible to the general population, and can be used in the whole population. Physical activity can potentially prevent functional decline associated with aging and promote global health status. In recent years, a growing interest has been given to the impact of physical activity as a protective factor for cognitive decline and for the progression for dementia There are several explanations for the protective effect in cognition: physical activity can implicate a better physical and global mental status, but can also be mediated through metabolic, physiopathological effects, as the increase cerebral inflow, the reduction of vascular risk factors, the decrease of production of stress hormones or still better endothelial function, among others.

However, there is no consensus in this field.

Some studies showed a protective effect of physical activity in Alzheimer disease. Protective effect of physical activity on vascular cognitive impairment (including dementia) has still to be proved. There are small studies with short follow-up, that do not take in consideration relevant confounding factors or imaging data (e.g. evidence of small vessel disease) with controversial results.

Recently a large observational study showed the beneficial impact of physical activity (defined according to the American Heart Association as at least 30 minutes of physical activity at least 3 times a week) in the reduction of the risk of progression for vascular dementia, in a cohort of subjects older than 65 years old, living independently, with cerebral white matter changes, and controlling for confounding factors. Additionally, in subjects with evidence of small vessel disease and no cognitive decline, physical activity was associated with better executive performance overtime.

The existing studies do not come from adequate randomized and double-blind designs, so there is no evidence-based data to sustain a recommendation for the type, intensity or frequency of physical activity, and the long-term gain. Given these contradictory findings, it becomes relevant to have an evidence-base to recommend physical activity in vascular cognitive impairment and in what concerns the type, intensity, and frequency of activity which would be necessary to achieve longterm gains.

Inclusion criteria

• Participants are included if they are older than 18 years
• Fluent in Portuguese language;
• Able to read and write;
• Availability of a reliable informant;
• Fulfill the written informed consent;
• Clinical and functional criteria A and B:
• Criteria A: 1 of the following 3:

• Probable mild cognitive vascular impairment;
• Previous ischemic or hemorrhagic stroke (at least 6 months before), with modified Rankin ≤ 2 at baseline and without formal indication for physiotherapy.
• TIA (at least more than a 1 month before), diagnosed by a neurologist or with identified vascular lesion (correlated with TIA clinical symptoms) in CT/MRI.
• Criteria B: No functional changes: IADL 0 (no item changed, or 1 single item with minimal change), according to the scoring methods of the LADIS study (minimum of 4 items applicable) or no cognitive changes regarding the suggested Montreal Cognitive Assessment Test (Moca) cut off point for dementia in clinical Portuguese samples (score < 17).

Exclusion criteria

(Subjects cannot be included if they have at least one of the following):

• Diagnosis of dementia;
• Stroke with formal indication for physiotherapy or speech therapy, or Rankin ≥ 2;
• Any contraindication for walking, physical limitation to gait (orthopedic or other structural) that compromises the therapy proposed, or physical or mental limitation that could potentially interfere with the active treatment proposed (e.g. severe arthritis, severe osteoarticular pain associated with walking);
• Evidence of neurodegenerative disease (other than vascular aetiology), significant psychiatric disease (e.g. major depressive episode) or medical disease with prognosis or severity which could significantly interfere with the subjects' participation, or with quality of life (e.g. cancer, severe cardiovascular disease as congestive heart failure, uncontrolled angina).