Lyme Disease Dementia: When Symptoms Are Mistaken for Aging
Lyme disease in older adults may mimic dementia or stroke
Neurologic Lyme symptoms are sometimes reversible with treatment
Delayed diagnosis can lead to serious complications
Lyme disease in older adults may sometimes resemble dementia, stroke, psychiatric illness, or progressive neurologic decline.1,2
Several published case reports describe patients initially misdiagnosed with aging-related disorders before later being diagnosed with neurologic Lyme disease.1,2
Patients may present with confusion, hallucinations, balance problems, memory loss, speech difficulty, neuropathy, cardiac abnormalities, or sudden neurologic decline.1-7
In some cases, symptoms improved significantly following antibiotic treatment.1-6
She was in her late 60s. No autoimmune history. No recent travel. But she was getting weaker. Her joints ached. Her memory was slipping. Her balance felt off. She woke up exhausted, sometimes with her heart racing.
She was told it was aging.
Then anxiety.
Then nothing more could be done.
But when we looked closer, the story pointed to Lyme disease.
For a broader overview of neurologic complications, visit our Neurologic Lyme Disease hub.
Lyme Disease in Older Adults Is Often Missed
I’ve seen this pattern repeatedly in clinical practice: an older adult develops multisystem symptoms and is told it reflects aging, stress, depression, or another chronic condition.
But when Lyme disease is missed—especially in older adults—the consequences can become severe.1-7
Published reports describe Lyme disease presenting as:1-7
- dementia
- stroke
- hallucinations
- seizures
- heart block
- neuropathy
- cognitive decline
Fortunately, some neurologic manifestations improved after treatment when Lyme disease was recognized.1-6
Neurologic Lyme Disease That Looked Like Dementia
Case 1: Reversible Dementia in a 75-Year-Old Man
A man was admitted to an Alzheimer’s unit with hallucinations, confusion, aggression, incontinence, and insomnia.1
Imaging was unremarkable, but Lyme serology was positive.1
After a 21-day course of IV ceftriaxone, many symptoms improved significantly.1
Clinical insight: Lyme neuroborreliosis can mimic dementia but may improve if recognized and treated early.
Case 2: Stroke in an 83-Year-Old Man
An 83-year-old developed sudden weakness and speech loss.2
No vascular risk factors were identified, but blood and spinal fluid testing were positive for Borrelia.2
Following IV antibiotics, his condition stabilized.2
Clinical insight: Lyme disease should be considered in elderly stroke patients without a clear explanation.
Case 3: Recurrent Strokes From Cerebral Vasculitis
A 58-year-old man experienced repeated strokes affecting the same brain region over the course of a year.3
Testing confirmed Lyme disease.3
After doxycycline treatment, recurrent strokes stopped.3
Clinical insight: Lyme-induced cerebral vasculitis is rare but potentially treatable.
Lyme Carditis and Heart Block
Case 4: Third-Degree AV Block Reversed With Treatment
A patient developed complete heart block caused by Lyme carditis.4
With IV ceftriaxone and temporary pacing, heart rhythm normalized and a permanent pacemaker was avoided.4
Clinical insight: Cardiac Lyme disease may cause life-threatening conduction abnormalities but can improve with early treatment.
When Lyme Disease Does Not Look Like Lyme
Case 5: Seizures in a 55-Year-Old Man
A man with no classic Lyme symptoms presented with generalized seizures.5
Lyme serology and spinal fluid testing confirmed neuroborreliosis.5
After ceftriaxone therapy, seizures resolved.5
Clinical insight: Lyme disease may present with seizures even without rash or flu-like symptoms.
Case 6: Neuroborreliosis Without Rash in an 84-Year-Old
An elderly man developed confusion and headaches without a rash.6
Lyme testing was positive.6
With antibiotic treatment, he recovered fully.6
Clinical insight: In older adults, neurologic Lyme disease may occur without classic early Lyme symptoms.
Peripheral Neuropathy and Progressive Damage
Case 7: Charcot-Like Neuropathy From Untreated Lyme Disease
A patient developed a severe deforming neuropathy resembling Charcot foot.7
Testing confirmed untreated Lyme disease.7
Clinical insight: Untreated Lyme disease may contribute to progressive neuropathy and musculoskeletal damage.
Why Lyme Disease Is Missed in Older Adults
Older adults may not recall a tick bite or rash.
Symptoms may overlap with:
- dementia
- vascular disease
- Parkinsonian syndromes
- depression
- neuropathy
- cardiac disease
Some patients are also incorrectly reassured by negative testing despite strong clinical suspicion.
Delayed diagnosis may increase the risk of neurologic complications and prolonged illness.1-7
Frequently Asked Questions
Can Lyme disease look like dementia?
Yes. Published case reports describe Lyme disease causing confusion, hallucinations, cognitive decline, and dementia-like symptoms.1
Can Lyme disease cause reversible dementia?
Some neurologic symptoms improved significantly after antibiotic treatment in published case reports.1-3
Can Lyme disease cause stroke symptoms?
Yes. Lyme neuroborreliosis has been associated with stroke-like presentations and cerebral vasculitis in rare cases.2,3
Does Lyme disease affect older adults?
Yes. Older adults may develop neurologic, cardiac, and systemic manifestations of Lyme disease.1-7
Can Lyme disease be mistaken for aging?
Yes. Fatigue, cognitive decline, balance problems, neuropathy, and memory issues may incorrectly be attributed to aging.
What neurologic symptoms can Lyme disease cause?
Neurologic Lyme disease may cause cognitive dysfunction, headaches, neuropathy, dizziness, hallucinations, speech problems, seizures, and balance impairment.1-7
Clinical Takeaway
Lyme disease in older adults may present with neurologic, psychiatric, cardiac, or vascular symptoms that resemble dementia or other age-related disorders.
Published case reports demonstrate that some severe neurologic manifestations improved following antibiotic treatment.1-6
Clinicians should maintain suspicion for Lyme disease when older patients develop unexplained cognitive decline, stroke-like symptoms, neuropathy, or multisystem illness.
Related Articles
These related articles explore neurologic Lyme disease, cognitive symptoms, delayed diagnosis, and persistent neurologic complications.
Neurologic Lyme Disease
Lyme Disease Symptoms Guide
Delayed Lyme Disease Diagnosis
Post-Treatment Lyme Disease Syndrome
Can Lyme Disease Cause Speech Problems?
References
- Sanchini C, Papia C, Cutaia C, Poloni TE, Cesari M. A case of reversible dementia? Dementia vs delirium in Lyme disease. Ann Geriatr Med Res. 2023;27(1):80-82.
- Eur J Case Rep Intern Med. 2025. Lyme neuroborreliosis in elderly patient
- Back T, Grünig S, Winter Y, et al. Recurrent stroke due to cerebral vasculitis: rare presentation of neuroborreliosis. Cerebrovasc Dis. 2013;36(1):64–65.
- McAlister, H. F., Klementowicz, P. T., Andrews, C., Fisher, J. D., Feld, M., & Furman, S. (1989). Lyme carditis: An important cause of reversible heart block. Annals of Internal Medicine, 110(5), 339–345.
- Müllegger RR, Glatz M. Lyme borreliosis: Clinical manifestations, diagnosis, and management. Curr Probl Dermatol. 2009;37:18–38.
- Legast, G. M., Schnider, A., & Nicastro, N. (2018). Ischemic stroke: Do not forget Lyme neuroborreliosis. Case Reports in Neurological Medicine, 2018, 1720725..
- Adams, H. B., Blasko, G. A., & DiDomenico, L. A. (2002). An unusual case of bilaterally symmetrical neuropathic osteoarthropathy of the midfoot as a result of Lyme disease-induced peripheral neuropathy: A case report. Foot & Ankle International, 23(2), 155–157.
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Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
