Fatigue, pain often accompany chronic Lyme disease

Because Lyme disease is difficult to diagnose in the absence of the characteristic "bull's eye rash," the illness can become entrenched and difficult to treat.

In such cases, symptoms such as memory loss, irritability and fatigue, may predominate, according to a study presented at the sixth annual Lyme Conference in Philadelphia.

"No one was studying chronic Lyme disease, yet a growing number of patients were suffering with chronic persistent symptoms even after antibiotic treatment," said lead investigator Dr. Brian Fallon, from Columbia University in New York.

For their study, sponsored by the National Institute of Neurology and Stroke, Fallon's group recruited 37 patients who met strict conditions for having chronic Lyme disease. The team conducted brain-imaging studies and assessed the participants' response to re-treatment.

Secondary Lyme disease is an inflammatory disease characterized by cardiac and neurological symptoms caused by the bacterium Borrelia burgdorferi, which is transmitted by the bite of a deer tick.

Causes, incidence, and risk factors

See Lyme disease for a description of the initial stages of the disease. Secondary Lyme disease develops within days to months after the tick bite, when the infection spreads via the lymph system or bloodstream.

The central nervous system and cardiac system may be affected. Symptoms may be intermittent and may disappear after days, weeks, or months. Involvement of the heart occurs in 8% of people with untreated Lyme disease. Neurologic involvement occurs in 10% of patients with untreated Lyme disease.

"Based on objective tests of physical impairment, we found that the patients had levels of functional disability comparable to what you would see with congestive heart failure, as well as pain comparable to what you might expect in patients coming out of surgery, and fatigue comparable to patients with multiple sclerosis," Fallon said.

Moreover, brain-imaging studies showed "that there are widespread deficits in blood flow and metabolism in patients compared to age- and education-matched controls."

"From a strictly objective stance these patients are quite impaired," Fallon maintained. "Chronic Lyme disease clearly exists and represents a major public health problem."

The researcher said that once chronic Lyme disease patients have been treated with a 3-week course of antibiotics, they are often told that any remaining symptoms are of a psychiatric nature.

"So patients are not only are experiencing a disease causing significant disability and pain, they are also experiencing invalidation of their illness by being told they are making it up, that 'it's all in their head'," he said.