BY: Jovanda Biston

Staying awake is a never-ending struggle for Tan Liying. Without the medication that she takes twice a day, she would be constantly drowsy, or she would simply fall asleep.

The 17-year-old student suffers from narcolepsy, a neurological disorder that causes episodes of sudden daytime sleepiness (sleep attack), usually preceded by drowsiness.

Liying was diagnosed with narcolepsy when she was 10 years old. Her mother, Madam Lim, said she and her husband began to notice that their usually active and lively daughter was frequently tired and lethargic.

They reprimanded their daughter, who was then in Primary 4, for being lazy and for napping when she should have been doing her homework.

'Initially, my husband and I thought that she was exhausted from her many activities. She swam, participated in athletics, choir and Chinese orchestra. We thought she might be over-exerting herself,' recalled the 45-year-old housewife.

Then Madam Lim noticed other changes in her daughter and she began to worry that Liying's condition might not be a simple case of exhaustion. The girl would also occasionally fall over when she was standing and she had many bruises on her body.

Madam Lim said: 'She would be standing still and talking to me or laughing and she would suddenly fall.'

After several visits to a polyclinic, Liying was referred to KK Women's and Children's Hospital for a sleep study.

There, Madam Lim and her husband, both of whom knew nothing of the condition, were informed that Liying had narcolepsy.

Her teachers were told of her condition but that did not make academic life any less of a struggle.

Liying was a top EM1 student until she was in Primary 4. Narcolepsy affected her studies.

Her results took a nosedive and she was almost retained in Secondary 1. She once failed an examination in Chinese - a subject that was usually her forte - because she had fallen asleep during the entire Listening Comprehension section.

Schoolmates ridiculed her for her frequent bouts of drowsiness and her need for naps, calling her names such as 'alien'. Liying said that even teachers picked on her and frequently reprimanded her for being inattentive in class.

Madam Lim teared when she recalled the attitude of Liying's teachers towards her daughter's condition. Strangers too have often been unkind. Liying frequently twitches and jerks in her sleep and this has provoked fear in them.

'She frequently falls asleep on my shoulder when we are on the MRT. People pull away from her or stare. Once, someone even asked if my daughter is possessed,' she said.

Madam Lim's concern for Liying's condition has occasionally caused friction between mother and daughter. Madam Lim frequently sends Liying SMSes when she is in school to check if she is well and awake and she discourages her from going out with friends in the evenings.

Liying said: 'Sometimes I do get frustrated but I know my mum means well."

Liying, who snacks often, said that munching on dried guava and chocolate sticks helps keep her awake.

She hopes to find work in the food and beverage industry after completing her studies.

'A job that involves quite a bit of physical activity is good because it would keep her awake. I also do not want her to work in a place where her condition might endanger her or those around her,' said Madam Lim.

Liying hopes to find understanding among employers and colleagues when she enters the workforce. The few school friends to whom she has confided in about her narcolepsy have been less than sympathetic.

'When they learnt that I have a disorder that causes me to sleep too much, they tell me that I am lucky because many people have trouble sleeping,' she said.

Poor awareness

Dr Jenny Tang, deputy head of paediatric medicine at KK Women's and Children's Hospital (KKH), said that the exact cause of narcolepsy is not known but genetic and environmental factors are believed to play a role in it.

Narcoleptics can experience sleep attacks at any time during the day, even when they are talking to someone.

These sleep episodes can be brief - each may last less than half an hour.

Dr Tang, who is also the head and senior consultant of KKH's respiratory medicine service, said that narcolepsy is broadly divided into two main classes - narcolepsy associated with temporary and sudden muscle weakness called cataplexy, and narcolepsy without cataplexy.

She said that the peak onset age of narcolepsy is between 15 and 25 years but it may occur in younger children as early as two years of age.

However, many narcoleptics may not be diagnosed until several years after the onset of symptoms.

Dr Tang, who has treated Liying, writes to her patients' teachers about their students' condition. She thinks there is poor awareness of narcolepsy in Singapore because of the low prevalence - the condition affects only about 0.05 per cent of the population.

'When awareness of the condition improves, there might be greater empathy for narcoleptics," said Dr Tang.

No cure

Narcolepsy is a chronic, life-long condition for which there is no known cure. Treatment for the disorder aims to control the symptoms and maintain wakefulness.

The Center for Narcolepsy at the Stanford University School of Medicine in the United States describes the condition as a very disabling and under-diagnosed illness.

The effect of narcolepsy on its victims is devastating because even treated narcoleptic patients are often markedly psycho-socially impaired in the area of work, leisure, interpersonal relations and are more prone to accidents.

This article was first published in Mind Your Body, The Straits Times on Dec 11, 2008.