Nancy Kwok had always prided herself on her razor-sharp memory, so when little things began to slip her mind - like what she'd eaten the day before - the 70-year-old thought it was just due to old age.
It wasn't until Kwok (whose name has been changed for patient confidentiality reasons) started forgetting whether she'd paid bills and had trouble expressing herself that her son, Richard, knew something was wrong. She was diagnosed with Alzheimer's disease.
"My mum used to be so full of life, but as these problems got worse, she became increasingly frustrated and withdrawn," says Richard. "She seems to have stabilised a little, thanks to medication, but she's not the same person and her quality of life has deteriorated."
According to a recent paper in the Hong Kong Medical Journal, about 6.1 per cent of elderly Hongkongers have Alzheimer's disease. That figure is rising because the population is ageing and age is the biggest risk factor, says Dr Gary Small, director of the UCLA Longevity Centre. Women are at a greater risk, partly because they tend to outlive men.
Alzheimer's is the most common form of dementia. Small says it's an "accumulation of abnormal protein deposits - plaques and tangles - in brain regions that control memory and other cognitive abilities".
There are many factors that cause Alzheimer's. Genetics is believed to play a role - about 30 to 40 per cent - and the rest is due to lifestyle and other non-genetic factors. Dr Chong Mei-sian, senior consultant at the department of geriatric medicine at Tan Tock Seng Hospital in Singapore, says diabetes, heart disease and hypertension are strong risk factors.
Alzheimer's symptoms typically begin after the age of 65 with short-term memory loss. Small says certain symptoms of mild Alzheimer's may be similar to other conditions or the side effects of some medications, so a proper medical evaluation is required.
As the condition worsens, sufferers may have trouble with simple tasks such as getting dressed and eating. They often become withdrawn, agitated and aggressive as they struggle with basic functions. This affects caregivers and family members; caregivers have a 50 per cent risk of developing depression, says Small.
There are treatments - both drug and non-drug - to slow the progression of Alzheimer's and temporarily ease symptoms. But Dr Kay Li-chi, a specialist in neurology at Hong Kong Adventist Hospital, says not much can be done to reverse or prevent Alzheimer's. However, staying active, keeping up with one's hobbies and becoming more social can greatly improve the sufferer's quality of life.
It's important to keep chronic medical conditions such as hypertension and diabetes under control, and to live healthily and maintain a positive mental attitude. Small's book, The Alzheimer's Prevention Program: Keep Your Brain Healthy for the Rest of Your Life, details the physical exercises, cognitive training and nutritional factors that can help delay the onset of the disease.
New research shows there might be a way to detect if a person is at an increased risk of developing Alzheimer's. Erin Johns, a doctoral student at Concordia University's Department of Psychology, says small impairments in memory and "executive functioning problems" may be a sign of early-stage Alzheimer's. These include problems with attention, planning activities and making decisions.
Johns wants to make it easier to be able to identify such people "so they can be targeted for preventive strategies that would stop brain damage progressing". It's a chance to help them know what to expect and how to cope, she says.
This month, researchers in the United States reported that an experimental drug called bapineuzumab showed positive effects in patients with mild to moderate Alzheimer's. It is made to work on the biology of the disease, removing the plaque that damages nerve cells in the brain. Researchers will now test the drug on people with mild mental impairment.
As for a cure, Small says drugs and vaccines are being tested all over the world. "The strategy is to develop a treatment that forestalls the onset of symptoms," he says. "[But] while we are waiting for science to catch up, lifestyle strategies offer a chance to nip symptoms in the bud."