Difficulty orienting oneself and finding one's way around the environment, also known as "topographical disorientation" (TD) or "spatial disorientation" (SD), is a common and often early symptom of Alzheimer's disease (AD) that affects people's independence and well-being. Being able to identify it is therefore crucial in order to provide appropriate support.

It cannot be assessed using conventional psychometric tests due to its low ecological validity. Several subjective assessment scales have been created to screen for SD "spatial disorientation" and assess its functional and psychological impact. However, none of these scales have been translated and validated in French. As a result, DS is not assessed in routine clinical practice.

Among these scales, the Wayfinding Questionnaire (WQ) explores three dimensions: spatial orientation, distance estimation, and spatial anxiety. This questionnaire has undergone psychometric validation studies in its original Dutch version for a population with mild post-stroke , and norms for the general population have been published.

Our team translated this questionnaire into French (i.e., "Questionnaire d'Orientation Spatiale" (QOS)) and adapted it cross-culturally to preserve the qualities of the measurement. A "Caregiver" version was also created, taking into account the anosognosia known to occur in AD. Primary Objective : Evaluate the psychometric properties of the Spatial Orientation Questionnaire (SOSQ) (i.e., the French translation and adaptation of the Wayfinding Questionnaire) in assessing spatial orientation disorders in patients with Alzheimer's disease, in both its "patient" and "caregiver" versions. Secondary objective : Evaluate the acceptability of the Spatial Orientation Questionnaire (SOC) in its "patient" and "caregiver" versions.

Inclusion Criteria:

For all subjects :

• Native French speakers
• Independent mobility: (minimum mobility range of 3 (i.e., neighborhood) on the LSA-F assessment of the mobility zone scale)
• Person affiliated with a social security system or beneficiary of such a system

Patients (Subgroup A1) and healthy control subjects (Group C):

• Individuals who have received complete information about the clinical research organization and have signed their written informed consent
• Patients (Subgroups A2 and A3) and Companions (Group B) Individuals who have received complete information about the clinical research and have agreed to participate

Patients (group A):

• Aged 55 to 85
• Diagnosis of probable Alzheimer's disease (NINCDR-ADRDA diagnostic criteria)
• Score of 4 or less on the Hachinski Ischemic Scale
• Score of 20 or higher on the Folstein MMSE (Mini Mental State Examination)
• In the case of specific treatment for Alzheimer's disease (anticholinesterase and memantine treatments), treatment stability for > 15 days
• Able to walk independently, i.e., without assistance, whether human or technical, except for a simple cane

Caregivers (group B):

• Caregivers of a person with dementia included in group A, with regular contact (at least 10 hours per week, spread over a minimum of 3 times per week)
• Healthy control subjects (group C):
• Aged 55 to 85
• Able to walk independently, i.e., without assistance, whether human or technical, except for a single cane
• Normal performance on the Folstein Mini-Mental State Examination (MMSE), according to GRECO (Cognitive Assessment Task Force) standards

Exclusion Criteria:

For all subjects:

• Adults subject to legal protection measures (guardianship, curatorship, judicial protection)
• Adults unable to give their consent
• Persons deprived of their liberty by judicial or administrative decision, persons receiving psychiatric care pursuant to Articles L. 3212-1 and L. 3213-1.
• Persons capable of giving consent but unable to read French
• Persons capable of giving consent but unable to write
• One of the members of the patient/caregiver dyad refusing to participate in the study.

Patients (subgroup A1) and healthy control subjects (group C):

• Sensory or phasic deficit interfering with the task.
• History of moderate or severe head trauma (with loss of consciousness).
• Change in psychotropic treatment less than 48 hours before the tests
• Chronic alcoholism
• Severe depression (score greater than or equal to 10 on the GDS-15 Geriatric Depression Scale)
• Presence of other clinically significant psychiatric or neurological conditions (except Alzheimer disease for case subjects)

Patients with Alzheimer disease and their caregivers