Skip to Accessibility Tools Skip to Content Skip to Footer
A person gets bitten by a tick.

Is There a Link Between Lyme Disease and Neurodegenerative Disorders?

Many people with disorders that affect the brain wonder if there is a link between their disease and Lyme disease (LD). These brain disorders can include Parkinson’s disease, Alzheimer’s disease, and multiple sclerosis. Researchers also decided that they wanted to see if there was any link between LD and other brain disorders.

What is Lyme disease?

LD is a bacterial infection that is transmitted by a tick bite. It can lead to many health problems. These problems may include rashes, swelling in the heart, and joint pain in multiple joints at once.1 Sometimes, LD can lead to brain issues. Some of these brain issues are dementia-like symptoms, swelling in the brain, shaking in the hands, and memory loss.1,2,3,4 Patients may also have symptoms of LD months to years after the initial tick bite and treatment. These symptoms are called Post-treatment Lyme Disease Syndrome or sometimes called chronic Lyme disease.5

Lyme disease and Alzheimer’s disease by location

Two groups of researchers wondered if there were any links between deaths from Alzheimer’s disease (AD) and LD. If there was a link between AD and LD, then states that have the highest numbers of cases of LD should also have the highest numbers of AD deaths.2,3 The information was easy to find. States keep records of the number of cases of LD that are diagnosed each year. States also keep records of the cause of death on a person’s death certificate. The researchers looked at states where the cases of LD were the highest and states where the cases of LD are the lowest. They looked at the number of deaths caused by AD in those same states.3 They found that there was no link between the deaths because of AD and the number of cases of LD. In fact, the number of deaths from AD was actually higher in many states with the lowest number of cases of LD.2,3

No research is perfect. The researchers know that their information doesn’t take into consideration people who have LD that may have moved to different states after they are diagnosed. It also can’t account for how different states record the cause of death on a certificate.2 Both of these factors have the potential to change some of the results. Even with these problems, these studies do show that there is very little link between Lyme and deaths due to AD.2,3

A case of Lyme disease and Parkinson’s disease

Some people with LD will have symptoms of brain problems after their diagnosis. These problems can include memory loss and shaking of the hands and feet. Most of these problems go away after the person takes medications to treat LD.3 There is one time that a person had symptoms of Parkinson’s disease after his treatment for LD. These symptoms continued to get worse until the person eventually passed away.1 This is the only case that doctors know of someone who developed Parkinson’s disease from LD. This case of Parkinson’s disease was verified by an autopsy. This person had no brain symptoms before his LD diagnosis. Researchers don’t know if the LD caused the Parkinson’s disease symptoms, or if this person would have developed Parkinson’s disease without having LD.

No connection

LD and brain disorders can share many symptoms. So far, there has been no proof that there is a connection between LD and brain disorders.2-4 Researchers are actively looking for the cause of many brain disorders. This is very important for researchers studying AD.2 Knowing what causes these diseases may help researches find a cure. There may be more studies looking at the link between LD and AD, Parkinson’s disease and MS in the future. Until then, researchers have shown that there is little to no link between LD and these other diseases.

  1. Cassarino D, Quezado M, Ghatak N, et al. Lyme-Associated Parkinsonism: A Neuropathologic Case Study and Review of the Literature. Archives of Pathology & Laboratory Medicine 2003 127:9, 1204-1206. doi: 10.1043/1543-2165(2003)
  2. Forrester JD, Kugeler KJ, Perea AE, et al. No Geographic Correlation between Lyme Disease and Death Due to 4 Neurodegenerative Disorders, United States, 2001–2010. Emerging Infectious Diseases. 2015;21(11):2036-2039. doi:10.3201/eid2111.150778.
  3. O'Day D, Catalano A. A Lack of Correlation between the Incidence of Lyme Disease and Deaths due to Alzheimer's Disease. Journal of Alzheimer's Disease. 2014;42(1):115-118. doi:10.3233/jad-140552
  4. Kristoferitsch W, Aboulenein-Djamshidian F, Jecel J, et al. Secondary dementia due to Lyme neuroborreliosis. Wien Klin Wochenschr. 2018;130(15-16):468–478. doi:10.1007/s00508-018-1361-9
  5. Post-Treatment Lyme Disease Syndrome | Lyme Disease | CDC. Published 2019. Accessed 10/31/2019.


  • Dan Glass moderator
    1 month ago

    Lyme is the “Great Imitator.” When I was diagnosed with PD, they also found I had Lyme. Fortunately, it didn’t go into my cerebrospinal fluid! A bunch of doxycycline horse pills did the trick. If only that worked for PD as well!

  • Poll