“Ask Dr. HKSH” - Alzheimer’s Disease

Dr. SHIU Ka Lock

HKSH Specialist in Neurology

Q1. Is dementia the same as Alzheimer's disease?

Dementia occurs when neurons in the brain are damaged by certain neurological disorders or other diseases, causing far more extensive decline in cognitive functions than normal aging. Up to 70% of dementia are caused by Alzheimer's disease. Other causes include vascular dementia, Parkinson’s disease dementia, dementia with Lewy bodies, and certain reversible disorders, such as hypothyroidism, deficiency in vitamin B12 or folate etc.

Q2. What are the differences between forgetfulness and Alzheimer's disease? When should one seek medical advice?

While we all experience mild cognitive changes as we age, those with Alzheimer's disease may notice a decline in memory, particularly short-term memory. They may keep asking the same questions, have difficulty finding the right words or expressing thoughts clearly, or need more time to recall certain terms. Once manageable, day-to-day activities like doing simple calculations while shopping, or managing finances, may become too much for them to handle, not to mention planning or organising daily tasks. If you have these issues or concerns, please consult a doctor for professional advice.

Q3. Is Alzheimer's disease related to lifestyles or other diseases?

Besides age and certain high-risk genetic factors, risk factors for cardiovascular and cerebrovascular diseases, such as diabetes, high blood pressure, high cholesterol, and obesity, can increase the likelihood of developing Alzheimer's disease. Unhealthy lifestyles, including smoking, alcohol consumption, lack of physical activity, vision and hearing loss, lack of social interaction, etc. may also increase the risk.

Q4. How is Alzheimer's disease diagnosed?

Doctor will first review one’s medical history to rule out potential sleep-related disorders or mental health conditions. Medications are also reviewed to ensure the symptoms are not caused by drug side effects or interactions from multiple medications. A comprehensive physical and neurological examination is then conducted to exclude reversible causes of cognitive changes. Neuropsychological tests, such as the Montreal Cognitive Assessment (MoCA), may be arranged to evaluate one’s current level of cognitive function.

Blood tests are now available to screen Alzheimer's disease biomarkers. Doctor also order neuroimaging studies to rule out cerebrovascular disease, brain tumours, or other less common disorders that can affect cognition, such as hydrocephalus. PET scans can detect abnormal deposits of amyloid and tau proteins in the brain with high precision, thereby confirming a diagnosis of Alzheimer's disease.

Q5. How is Alzheimer's disease treated?

Alzheimer's disease can be managed with symptomatic treatments, such as cholinesterase inhibitors or glutamate receptor antagonists. These medications can alleviate cognitive symptoms and reduce emotional or behavioral issues.

In recent years, anti-amyloid therapies have become available to clear abnormal amyloid plaques in the brain and prevent formation of new plaques, thereby slowing down the progression of cognitive decline in patients with early-stage Alzheimer's disease. These medications are injected regularly. Regular MRI scans are also performed for possible treatment-related side effects.