Biomarkers of Sleep-wake Cycle in Prodromal Alzheimer's Disease: Role in Cognitive Decline?

This study is investigating how sleep disturbances relate to the progression of early Alzheimer's disease. Researchers will measure sleep-wake cycle biomarkers (from blood, spinal fluid, and body temperature) alongside cognitive tests to see whether disrupted sleep predicts faster cognitive decline and whether it could serve as an early warning sign. **You may be eligible if...** - You have been diagnosed with mild Alzheimer's disease (MMSE score 21–30) - You have a family caregiver who can help with questionnaires and diaries - You have already had, or are scheduled for, a lumbar puncture (spinal fluid test) as part of your standard care - You are covered by the French social security system **You may NOT be eligible if...** - You have a genetic (hereditary) form of Alzheimer's disease - You have recently started or changed Alzheimer's medications (unless stable for at least 3 months) - You are taking antidepressants, sleep medications, or antipsychotics - You live in a nursing home - You have medical reasons that prevent a spinal fluid test (such as a clotting disorder, skin infection at the puncture site, or spinal surgery) - You have severe physical or sensory problems that interfere with testing Talk to your doctor to see if this trial is right for you.