One of the little-understood ramifications of Lyme disease is its impact on cognitive function. Many people who have the disease, including those in post-treatment, report lingering brain-related issues. Scientists in the last few years are trying to find objective results that support these subjective claims.
Research has shown that in some patients, Lyme disease leads to cognitive impairment, especially in verbal memory and processing speed. Another showed an increase in chemical markers that lead to brain inflammation, which has been associated with dementia and other neurodegenerative disorders.
Some also have found an association between Lyme disease and mental health, including increased risk of depression.
What Is Lyme Disease?
Lyme disease is the most common tick-borne illness in the United States, with about 300,000 cases diagnosed each year. The black-legged tick carries the disease, which is caused by a bacteria called Borrelia burgdorferi. It’s named after Lyme, Conn., where it was first identified.
The symptoms of Lyme disease include headache, fatigue, swollen lymph nodes, muscle and joint pain, fever and chills. Because of these symptoms, people sometimes mistake Lyme disease symptoms for the flu. But one of the most mysterious symptoms of Lyme disease involves long-term issues with “fatigue and brain fog that may last for years after their initial infection has cleared up,” according to Johns Hopkins Medicine. These cognitive symptoms typically impact about 10% of Lyme disease patients.
Lyme Disease and Cognitive Impairment
For decades, those who have had Lyme disease frequently complain of cognitive impairment, even after treatment with antibiotics is concluded. How frequently? A study led by researchers from Johns Hopkins University School of Medicine reported that 92 percent of Lyme disease patients in the study reported experiencing cognitive issues.
All 124 patients had experienced either physical or mental post-treatment Lyme disease syndrome (PTLDS). Evidence from 26 percent of the patients showed “significant cognitive decline” in the areas of memory and cognitive processing speed.
The gap between the number of people reporting “brain fog” and the number of issues subjectively proven in tests led some researchers to think perhaps the issue was psychosomatic and related to depression or anxiety. Certainly, depression is an issue with Lyme disease, with as high as 45 percent of patients reporting feelings of depression in some studies, according to the Global Mental Health Program at Columbia University.
But new research shows that something else may be involved: brain inflammation.
Brain Inflammation and Lyme Disease
According to another study from Johns Hopkins, a PET scan of the brains of those with PTLDS as compared to other brains showed higher levels of inflammation. The scans searched for a protein in different sections of the brain associated with inflammation. That found it at significantly higher levels in eight regions of the brain.
While researchers expected to find some inflammation, they instead found it widespread throughout the brain. Brain inflammation can cause the symptoms patients say they experience, including brain fog and difficulty in remembering. “The results suggest that drugs designed to curb neuroinflammation may be able to treat PTLDS,” the Johns Hopkins researchers wrote.
Hyperbaric oxygen treatment (HBOT) also can reduce brain inflammation and may hold promise in treating those who suffer cognitive impairment after getting Lyme disease. Those who have had Lyme disease can also benefit from knowing which foods can reduce the risk of brain inflammation.