As a tailor, Marcus Ho, 56, spent 20 years deftly drafting and cutting paper patterns. Ho (name changed for patient confidentiality reasons) would take measurements and do quick calculations in his head. But then he started to make repeated mistakes at work. His boss started to get annoyed with him, and he became dismayed at his errors.
Things got worse outside of work, too. Ho kept misplacing his possessions and had trouble differentiating between right and left. One day, he found that he could not navigate his way to his close friend's house, which he had been visiting every month. Then he lost his way at a familiar MTR station.
The situation took a turn for the worse when his boss - fed up with his deteriorating performance - fired him. Ho's wife was furious at her husband for losing his job over what she saw as laziness. But Ho knew by now that his condition was no common muddle-headedness. Anxious, confused and feeling helpless, he turned to his family doctor for answers.
The general practitioner then referred Ho to Dr K.W. Liu at the Prince of Wales Hospital's department of medicine and therapeutics, who has a special interest in cognitive impairment.
Liu and his team of experts saw that Ho had some signs of dementia but the symptoms were not typical of Alzheimer's disease, which accounts for 34 per cent of young-onset dementia cases (those that start before 65 years of age). Ho was a non-drinker, so alcohol-related causes were unlikely. To find the cause, Ho ran a battery of tests.
First, Liu had Ho do cognitive assessment tests including the mini-mental state examination to determine the degree of cognitive impairment. Ho appeared to have lower than normal cognitive abilities for his age and educational background. He also had difficulty drawing a clock showing 10 minutes past 10 and drawing a cube, which was very unusual given his job as a tailor. It revealed Ho's poor visual-spatial ability in determining and navigating space.