The Bulawayo born professional, who has six European and 22 US tour victories was diagnosed with the disease in 2003 and doctors told him that he would never play golf again.
Recently he stunned the nation when he turned out for the Zimbabwe Open at Royal Harare Golf Club.
MS is an autoimmune disease where the body’s immune system starts to attack the central nervous system, for reasons, which are unclear.
Nerves are protected by a sheath made of a substance called myelin, which ensures the messages from the brain and spinal cord are transmitted to the rest of the body.
In MS, the immune system attacks the myelin, causing symptoms from tremors and difficulty with movement to impaired sight, hearing loss and paralysis.
Getrude Mapara, the Multiple Sclerosis Society of Zimbabwe executive member, said the society was happy with Johnstone’s coming back to golf, describing it as significant and good news to the MS sufferers in the country.
“He is an inspiration,” Mapara who also doubles up as the family therapist said.
The MS Society had 25 known members suffering from the disease but it was believed the disease was killing a lot of people in the rural areas because of wrong diagnosis.
Four of the known suffers of the disease are top executives in Zimbabwe.
“MS is not a cost effective disease. It is expensive to get a diagnosis of the disease, ”Mapara said.
Johnstone said he first realised he was not well in 2003.
“I was in absolute shambles,” he said. “My coordination was terrible and I felt a tingling sensation in my left hand. I forgot my son’s name, which was really awful, and I’d constantly repeat myself. I’d go out in the car and then forget where I was going and, at my lowest ebb, I didn’t know what I’d said 20 seconds ago. As for the golf, if you’d asked me to hit a ball into the Grand Canyon, I’d have missed. I don’t think I could have hit my foot with a club.”
Fearing he may have a tumour or even have suffered a stroke, Johnstone sought medical advice and was initially thought to have a viral infection and was put on a course of steroid treatment.
When that did not help, he had an MRI scan and was shattered to be told by the neurologist that he had MS.
“It was a dreadful shock and I just went and sat in the car and cried,” he said. “He told me to forget about being a tour professional but that was all I knew.”
“My wife, Karen, and I decided we would do everything to prove the specialists wrong,” Johnstone said.
He said he also owed his recovery to a remarkable trial involving Alemtuzumab. He was one of only 334 patients with MS to be included in the Cambridge University study. In fact he was the last candidate to be accepted on the three-year programme in October 2006.
Johnstone, who lives in Sunningdale, Berkshire with his wife Karen and two children, Dale, 23, and Lauren, 18, was very fortunate to been included in the MS study – especially as at first doctors were baffled by his symptoms.
Today he is one of the celebrities running a foundation in support for the MS disease.