Madam Doris Chan came home last November for a short visit from Cambodia, where she has been working as a missionary for the last 10 years.

Her plan was to stay for a week to see the doctor about a minor nose bleeding problem.

Then the symptoms started.

While having lunch with her friends, her left leg suddenly felt leaden and tired. She brushed it off as fatigue but, the next day, the feeling spread to her right leg and she could not lift it to get into a car.

By evening, the 61-year-old who is single could no longer stand.

After consulting a doctor in a nearby clinic, a friend quickly drove her to Mount Elizabeth hospital where she went through multiple magnetic resonance imaging (MRI) scans to rule out stroke and spinal injury.

In the meantime, neurologists carried out a few tests and, by the following day, discovered that she was suffering from a rare disease called the Guillain-Barré syndrome (GBS).

It is a disorder in which the body’s immune system attacks part of the nervous system, causing rapid muscle weakness that, in severe cases, can progress to a full body paralysis and death.

According to Dr Josiah Chai, consultant neurologist at the National Neuroscience Institute in Singapore, the disease attacks the nerves that help the muscles and brain communicate with each other.

"It’s like the HQ wants the soldier to move, but the soldier can’t because they are not getting the command from HQ," Dr Chai said.

There is no known cause for the disease but symptoms often first appear after an infection, such as flu, herpes or HIV.

After she was diagnosed with the disease, Madam Chan was transferred to St Luke’s Hospital in Singapore, for a long period of treatment and physiotherapy.

The shock she felt at hearing the news gradually gave way to the grind of coping with constant pain. She said: "In the day you long for night because of the pain. But the pain doesn’t go away and at night you long for morning. You just hope for relief but nothing works."

What helped to lift the burden was knowing what she had, even though doctors still have a limited understanding of this rare disease, which can affect anybody, any time, at any age.

"No doctor has been able to tell me how long it will take for me to recover," Madam Chan said sombrely.

Then, breaking into a wide smile, she said: "The nurses here are so warm and caring and my therapists are very encouraging and funny."

To encourage and sometimes trick her into standing or walking, they try different tactics .

Once, they got her a 500-piece jigsaw puzzle and asked her to piece it together, while standing, so that her leg muscles would remember and eventually get used to the position.

"I’ve done the bottom line and the part with flowers so far," she proudly proclaimed.

She in turn, has brought her therapists joy and laughter and is a model patient who needs no encouragement to do her own exercises.

"Doris has a positive outlook and always carries a cheerful demeanour," said physiotherapist Lee Yinjie.

More than six weeks into her treatment, she still needs help to stand up, but she can now remain standing by holding on to a table or walker. She still cannot walk but little things like being able to shift her foot gives her hope of full recovery.

Doctors do not know when she will recover but she will be discharged only when she is able to stand and walk on her own or with a walking aid, which could take three to six months.

Dr Chai said that a majority of the patients do recover fully, though some continue to have muscle weakness and need a walking aid to move around.

Meanwhile, Madam Chan has racked up $20,000 in medical bills, excluding her treatment at St Luke’s Hospital. They have been paid through her insurance, Medisave and a private donor.

The process is slow and frustrating but she knows she does not have to go through it alone.

"A lot of how I am managing is due to the overwhelming support that I am receiving from friends and loved ones," she said.

In fact, so many visitors have brought gifts and food that she put up a sign saying, "DO NOT FEED" next to her bed, amid the pile of cards, boxes of sweets and chocolates and books.

She admitted there are times she feels depressed and afraid she will never recover completely. When that happens, she said: "I cry, pray and text Esther for support."

Her close friend, Ms Esther Ong, 48, said that Madam Chan is strong and resilient.

"She’s had many health-related challenges but none of them have kept her down physically or emotionally for long," Ms Ong said.

mlwong@sph.com.sg