Alzheimer's Disease: Early Memory Loss, Progression Stages, and Management

Alzheimer's disease (AD) is the most common cause of dementia (60–80% of cases). The hallmark early symptom is impaired recent memory—difficulty learning and retaining new information—due to early medial temporal lobe involvement (entorhinal cortex, hippocampus).

Progression Stages

• Preclinical: Biomarkers positive (amyloid PET, CSF Aβ42/tau), no symptoms.
• Mild Cognitive Impairment (MCI): Memory complaint, preserved daily function.
• Mild dementia: Memory loss, word-finding difficulty, getting lost, financial errors.
• Moderate: Language, visuospatial, executive decline; behavioral changes; ADL assistance needed.
• Severe: Mutism, incontinence, immobility, total care dependence.

Pathology

• Extracellular amyloid-β plaques
• Intracellular neurofibrillary tangles (hyperphosphorylated tau)
• Neuronal loss, synaptic depletion, brain atrophy

Management

• Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) – mild to moderate.
• Memantine (NMDA antagonist) – moderate to severe.
• Anti-amyloid monoclonal antibodies (lecanemab, donanemab) – early symptomatic, modest slowing.
• Non-pharmacologic: cognitive stimulation, exercise, caregiver support, safety measures.

Early diagnosis enables planning, clinical trial access, and timely symptomatic treatment.