Retirement can be the start of a whole new relaxing phase of life or a chance to pursue dreams sacrificed for a lifetime of toil. For others it casts a pall over their sense of worth as a productive member of society and can lead to depression.
Hence, when newly retired Ng (whose full name has been withheld for patient confidentiality reasons) attended a private doctor at the age of 60 because of increasing forgetfulness, he was cast in the latter group.
The doctor dismissed Ng's slight memory loss as a symptom of emotional issues related to retirement after more than 30 years in government service. Adding to Ng's possible emotional strain, his mother had recently passed away. Just to be sure, though, the doctor had blood tests carried out and found that Ng had a vitamin B12 deficiency, which can contribute to memory loss.
He gave Ng oral B12 supplements and referred him to a public hospital for a follow-up.
By the time of Ng's appointment four weeks later, his condition had deteriorated drastically.
His anxious wife and children had brought him in for his appointment and the doctor knew that information loved ones could provide about a cognitively impaired patient could be key to an accurate diagnosis. So he listened carefully as the family told of the alarming changes in Ng.
For one, his memory loss was now so severe that he could not recognise his wife and children or remember their names.
Ng's personality had also undergone a stark change - previously loving and cheerful, he was now sullen and irritable. He would even spit indiscriminately.
He could no longer control his bladder or bowels, nor could he feed or bathe himself. Ng had also started walking clumsily and needed the aid of a walking stick.
Although Ng's wife was worried that he had dementia, the doctor noted that the combined symptoms - memory loss, personality change and physical impairment - within a period of just two months were danger signs that something else could be wrong with Ng's brain.
Ng was suspected to have a brain tumour and was referred to the Accident and Emergency Department of the Prince of Wales Hospital in Sha Tin for urgent investigation.
A computed tomography (CT) brain scan confirmed that a tumour some 5cm in diameter had grown in Ng's left frontal lobe.
The frontal lobe houses a person's personality, explaining the drastic changes in Ng.
A tumour of this size would likely have been growing inside Ng's brain for some years. However, his symptoms did not appear until the tumour was large enough to exert pressure on the brain tissue.
Luckily, the tumour was in a fairly accessible part of the brain and was operable.
Eight days after Ng's admission, doctors performed a craniotomy to completely remove the growth.
After the surgery, doctors confirmed that Ng had an atypical meningioma, which accounts for 7 per cent of tumours that originate from the meninges, or membranes covering the brain and spinal cord. Although most meningiomas are benign or non-cancerous, atypical meningiomas can be malignant. They grow slowly like benign tumours and can recur.
Meningiomas in general account for 15 per cent of brain tumours. Because they often have well-defined edges, it is often possible to remove them completely.
Although not every brain tumour needs to be removed immediately, the growth in Ng's brain was creating debilitating symptoms and required excision. Ng has now fully recovered from his operation.
A long-term relationship with a family physician can often be helpful in early detection of illnesses, especially cognitive-related ones.
Knowing a patient's history and disposition could help doctors assess whether one is prone to depression or other mental health conditions, or if personality changes may be caused by physiological problems.