SUNCT: a rare form of headache that strikes up to 200 times a day

For two weeks Hong Kong resident Brendan James suffered headaches on the left side of his face. His left eye had become red, producing sporadic tears, and while paracetamol was helpful at the beginning, the pain soon became unbearable. Simple painkillers were no longer effective.

"The pain was like touching a metal object that had built up a static electric charge, only 100 times stronger," says 35-year-old James, whose real name has been withheld for reasons of patient confidentiality. These "electric shocks" happened about 30 times an hour, and he could have as many as 200 attacks a day.

"When I had an attack, I had to stop doing whatever I was doing. I would sometimes miss a meal because I couldn't chew, or open my mouth without getting the attacks. At one stage the pain was so bad that I couldn't work."

James was initially thought to have cluster headaches, a condition that received media attention recently when British actor Daniel Radcliffe - aka Harry Potter - admitted he suffered from the syndrome.

Cluster headaches are not uncommon, occurring in one in 500 people, with the condition having a strong hereditary component, according to a 2004 study in the Lancet Neurology.

But James' case did not quite fit other cases of cluster headaches. While he had severe one-sided headaches and was producing tears, the number of attacks baffled doctors.