Alzheimer’s disease is the most common cause of dementia. It is a progressive brain disorder that gradually affects memory, thinking, language, judgement and the ability to perform everyday activities. While increasing age is an important risk factor, dementia is a medical condition and deserves proper evaluation, diagnosis and treatment.

Occasionally forgetting a name or misplacing the keys can happen at any age. The warning signs of Alzheimer’s dementia are different because they progressively interfere with daily life.

Common symptoms include:
• Frequently forgetting recently learned information
• Repeating questions or conversations
• Difficulty managing money, medications or household responsibilities
• Getting lost in familiar places
• Difficulty finding familiar words or following conversations
• Problems planning, organising or solving routine problems
• Losing interest in previously enjoyed activities
• Changes in personality, behaviour or judgement
• Increasing dependence on family members for everyday activities

Early symptoms may be subtle and are sometimes dismissed as “old age” or “normal forgetfulness.” This is why early assessment is important.

There is no single test that diagnoses every case of Alzheimer’s disease. A comprehensive assessment combines the patient’s history, neurological examination, functional assessment, cognitive testing, laboratory investigations and, when appropriate, brain imaging and biomarkers.

Cognitive testing is an important part of the evaluation. Memory, attention, language, executive functions, visuospatial abilities and other higher brain functions can be assessed using structured neuropsychological tests. Detailed testing can identify subtle cognitive changes even when routine conversation appears normal.

Today, cognitive assessment is also entering a new technological era. Computerised and AI-enabled cognitive assessments can complement traditional clinician-administered tests and provide objective measurements of different cognitive domains. However, technology should complement — not replace — expert clinical judgement.

An MRI brain can identify patterns of brain atrophy and also exclude other potentially treatable causes of cognitive decline, such as strokes, tumours, hydrocephalus or certain structural abnormalities. It is an important component of a comprehensive dementia evaluation.

MRI findings alone, however, do not establish Alzheimer’s disease. They have to be interpreted along with symptoms, cognitive testing and other investigations.

In selected patients, PET-CT brain can provide additional information about brain function and metabolism and may help the neurologist in evaluating certain complex or uncertain cases of cognitive decline.

PET-CT is not required for every person with memory complaints. It is recommended selectively, depending on the clinical presentation and the questions that need to be answered.

Amyloid PET and tau PET are more specialised molecular imaging techniques that can demonstrate Alzheimer’s-related pathology. They are currently used mainly in selected centres across the world and are particularly important in research and in specialised diagnostic and treatment pathways. These techniques are different from the routine PET-CT brain evaluation available in clinical practice.

One of the most exciting developments in dementia care is the emergence of blood-based biomarkers.

Researchers and clinicians can now measure Alzheimer’s-associated proteins such as phosphorylated tau (p-tau), including p-tau217, and amyloid-beta ratios in blood. Some blood-based tests have shown impressive diagnostic performance and are increasingly being incorporated into specialist assessment pathways.

These tests can potentially make Alzheimer’s evaluation more accessible and less invasive than PET scans or lumbar puncture. However, they should not be treated as stand-alone screening tests for everyone. Their interpretation depends on the clinical situation, the assay used and the expertise of the treating physician.

For many years, treatment for Alzheimer’s mainly focused on managing symptoms. Today, the landscape is changing.

Traditional medications such as donepezil, rivastigmine, galantamine and memantine can help manage cognitive and behavioural symptoms in appropriate patients, although they do not stop the underlying disease.

More recently, anti-amyloid monoclonal antibodies have introduced the concept of disease-modifying treatment for selected patients with early Alzheimer’s disease.

Lecanemab and donanemab have entered the Indian treatment landscape for appropriately selected patients with early Alzheimer’s disease, including mild cognitive impairment or mild dementia due to Alzheimer’s disease. These treatments are not suitable for every person with dementia. They require confirmation of Alzheimer’s pathology, careful assessment of disease stage and consideration of important safety issues, including amyloid-related imaging abnormalities and bleeding risk. Appropriate MRI monitoring and specialist supervision are essential.

Good dementia care extends beyond tablets.

Management may include treatment of vascular risk factors, sleep problems, depression and other medical conditions; cognitive stimulation; physical activity; healthy nutrition; occupational and neurorehabilitation strategies; management of behavioural symptoms; and education and support for caregivers.

Families also need guidance on medication safety, driving, finances, fall prevention, nutrition and future planning as the disease progresses.

Most importantly, a person with dementia should continue to be treated with dignity, patience and respect. The diagnosis may change how a person functions, but it does not take away their individuality, relationships or need for meaningful engagement.

Memory loss should not simply be dismissed as ageing.