Nancy Lamwaka is twelve years old, and suffers from a mysterious disease known as nodding syndrome.<br/> <br />Her father must tie her to a tree outside their grass hut in northern Uganda for her own protection.<br/> <br />The disease gives Nancy seizures and has diminished her mental capacity - she has lost the ability to talk and often wanders off, once getting lost in the bush for three days.<br/> <br />(SOUNDBITE) (Luo) MICHAEL ODONGKARA, LAMWAKA'S FATHER SAYING:<br/> <br />"It hurts me so much. In our tradition it is a taboo, it is not something heard of that you would tie someone to a tree but because I want to save her life, I don't want her to go to the bush and get burnt, I don't want her to go and drown in the river nearby and I don't want her to fall in fire. As you have seen, the wounds on her fingers are from falling in fire."<br/> <br />Nodding syndrome - named for the seizure-like episodes of head-nodding it causes - is a disease of unknown origins and no known cure.<br/> <br />The World Health Organisation says thousands of children in northern Uganda and southern Sudan are suffering from the condition.<br/> <br />Nancy's father has watched her slowly deteriorate since she contracted the disease in 2004, and says that if no cure is found, his daughter is as good as dead.<br/> <br />A WHO official said victims find it difficult to eat because of the seizures - which are often brought on by food - and become mentally and physically stunted.<br/> <br />(SOUNDBITE) (English) WHO HEAD OF DISEASE CONTROL FOR NORTHERN UGANDA, DR EMMANUEL TENYWA SAYING:<br/> <br />"There is a general effect in their neurological system to the extent that some can be impaired in vision, in eating even mere recognition of their immediate environment."<br/> <br />Most of the fatalities attributed to the disease are the result of secondary causes, with sufferers prone to accidents such as drowning.<br/> <br />While the effects of the disease - first documented in Tanzania in the 60's - are well known, researchers are still confounded by nodding syndrome, and the search both for its origins and a cure continue.<br/> <br />Nick Rowlands, Reuters.