Nancy Lamwaka, 12, is often tied to a mango tree to keep her from accidentally harming herself. Seizures have diminished her mental capacity. (STRINGER/REUTERS)

Most mornings, Michael Odongkara takes his daughter Nancy Lamwaka outside and ties her ankle to a mango tree.

It’s not something he likes to do. But the disease that gives the 12-year-old violent seizures has so diminished her mental capacity that she no longer talks and often wanders off. Once, she was lost in the bush for three days.

“It hurts me so much to tie my own daughter to a tree . . . but because I want to save her life, I am forced to. I don’t want her to [get] loose and die in a fire, or walk and get lost in the bushes, or even drown in the nearby swamps,” he said.

Nancy suffers from nodding syndrome, a disease of unknown origin and no known cure, which Ugandan authorities estimate affects more than 3,000 children in the country.

Named after its seizurelike episodes of head nodding, the disease, which mostly affects children between ages 5 and 15, has killed more than 200 children in Uganda in the past three years. Thousands of children in South Sudan are also sufferers.

Because the seizures are often triggered by food, children who have nodding syndrome become undernourished and mentally and physically stunted.

“There is a general effect on their neurological system to the extent that some can be impaired in vision, eating and even mere recognition of their immediate environment,” said Emmanuel Tenywa, a physician and adviser in disease control for the World Health Organization in Uganda.

As her father watched helplessly, Nancy cried out and began to convulse. Saliva flowed from her mouth, and her whole body shook for a few minutes until she finally went limp in the dust. Nancy has had episodes like this up to five times a day for the past eight years.

“When she was talking, she would ask for food,” he said. “These days she just stretches out her hand begging for it.”

Nodding syndrome was first documented in Tanzania as early as 1962. Half a century later, researchers still don’t know what it is.

“We have a long list of things that are not causing nodding disease. We still don’t have a definitive cause,” said Scott Dowell, director of the division of global disease detection and emergency response of the Centers for Disease Control and Prevention.

CDC officials were in Uganda for nine days in February on the latest of three trips to investigate the disease.

“We have ruled out, through our field studies and our laboratory testing, more than three different hypothesized causes including . . . 18 virus families with hundreds of members,” Dowell said.

It’s a relatively rare situation for the CDC to be in: Of 600 outbreaks of illnesses investigated by Dowell’s division, just six are unresolved.

The researchers do have some leads. One is a possible link with the black-fly-borne parasite that causes river blindness, or onchocerciasis. Researchers have also observed a deficiency of Vitamin B6 in the populations where the disease is prevalent.

With the cause of the disease unknown, officials are focusing on treating its symptoms. CDC researchers met with Ugandan health officials to discuss how a trial of treatments would work.

The trial, which could begin as early as May, will test two types of anticonvulsants as well as Vitamin B6 supplements. Some afflicted children are already on anti-epileptic drugs, with varying degrees of success.

“I think everybody is in agreement that at this stage it would be good to have a much better idea about what treatments are working and if any of them are harmful,” Dowell said.

Children with nodding syndrome are prone to accidents such as drowning and burning because of mental impairment, and many of the fatalities from the disease are the result of these secondary causes.

Since she contracted the disease, Nancy has had many such incidents. Her body is covered with bruises from falling, and there are raw, pink wounds on her hands from when she fell into a fire. “She doesn’t know that she is on fire, that she is burning, until someone comes and brings her away from the fire,” said her father.

He admits that he has stopped taking her to the doctor.

“Even if they give us drugs, I’m not sure if the drugs will help,” Odongkara said.

— Reuters