Lyme disease can cause seizures, though this is one of its rarer neurological complications. The bacteria responsible, Borrelia burgdorferi and related species, reach the central nervous system in roughly 3 to 15 percent of infections, and when they do, the typical results are meningitis, cranial nerve palsies, and nerve root inflammation rather than seizures.1PubMed Central. Guidelines for diagnosis and treatment in neurology – Lyme neuroborreliosis Seizures sit further down the list of possible outcomes, but documented cases in both adults and children make clear that the connection is real and worth understanding.
What Lyme Neuroborreliosis Typically Looks Like
When Borrelia bacteria cross into the nervous system, the condition is called Lyme neuroborreliosis. The classic presentation in Europe involves a triad of lymphocytic meningitis, facial nerve palsy, and painful nerve root inflammation.2The Open Dermatology Journal. Nervous System Involvement in Lyme Borreliosis In the United States, the picture tends to be a bit narrower, usually showing up as a slow-building meningitis with or without facial palsy.2The Open Dermatology Journal. Nervous System Involvement in Lyme Borreliosis These are the bread-and-butter neurological symptoms that clinicians in tick-endemic areas learn to watch for.
Less commonly, the infection can cause encephalomyelitis (inflammation of both the brain and spinal cord) or cerebral vasculitis (inflammation of blood vessels in the brain). A study examining MRI findings in patients with central nervous system Lyme disease found heterogeneous patterns including extensive spinal cord inflammation, brain lesions near the brainstem, and inflamed meningeal linings.3PubMed Central. Spectrum of MRI findings in central nervous system affection in Lyme neuroborreliosis These deeper brain and spinal cord involvements are rarer than simple meningitis, but they are the scenarios where seizures become plausible. When the brain itself is inflamed or its blood supply is disrupted, abnormal electrical activity can follow.
How Seizures Actually Happen in Lyme Disease
Two broad mechanisms connect Lyme infection to seizures, and they are not mutually exclusive. The first is direct damage from the infection and the inflammation it triggers. Borrelia bacteria can cross the blood-brain barrier by inducing host cells to produce enzymes that temporarily degrade the tight junctions holding the barrier together.4PubMed Central. Borrelia burgdorferi, host-derived proteases, and the blood-brain barrier Once inside the central nervous system, the bacteria provoke an intense immune response. Microglia, the brain’s resident immune cells, react to Borrelia by releasing a cascade of inflammatory signaling molecules.5PLoS Pathogens. Microglia Are Mediators of Borrelia burgdorferi–Induced Apoptosis in SH-SY5Y Neuronal Cells Astrocytes and neurons in the spinal cord also produce inflammatory signals in response to infection.6PubMed Central. Possible role of glial cells in the onset and progression of Lyme neuroborreliosis This sustained neuroinflammation can irritate brain tissue enough to lower the threshold for seizure activity, particularly when the infection involves the brain’s cortex or its blood vessels.
The second mechanism is autoimmune. Infections can sometimes trick the immune system into producing antibodies that target the body’s own neural tissue. A 2025 case report described two previously healthy patients, one a 25-year-old man and the other a 14-year-old girl, who developed new-onset seizures in the setting of Lyme disease. Testing revealed elevated antibodies against dopamine D1 receptors in both patients, and the adult also had antibodies against NMDA receptors, a type of brain receptor well known to cause seizures and psychiatric symptoms when targeted by the immune system.7PubMed Central. Autoimmune Epilepsy Temporally Associated With Lyme Disease: A Report of Two Cases Crucially, standard anti-seizure medications did not control their seizures, and the seizures actually worsened after antibiotics were started. It was immunotherapy, including corticosteroids and intravenous immunoglobulin, that brought lasting improvement. The authors were careful to note that this does not prove Lyme disease causes autoimmune epilepsy, but it raises the possibility that in some patients, the immune response to the infection does more damage to the brain than the bacteria themselves.
Seizures in Children With Lyme Disease
Children may be at particular risk for unusual Lyme presentations, including seizures. A study of childhood neuroborreliosis cases found that focal seizures were among the early symptoms that first raised suspicion of Lyme disease in some patients.8PubMed. CNS Lyme disease manifestation in children Another report described four unusual pediatric cases and noted that seizures with regional leptomeningeal enhancement on MRI (meaning inflammation of the membranes around the brain visible on imaging) can be a leading symptom in children with neuroborreliosis.9PubMed. Uncommon manifestations of neuroborreliosis in children
These pediatric cases matter for a practical reason. A child who develops unexplained seizures during or after the warmer months in a region with high tick exposure may not immediately get tested for Lyme disease, especially if there is no obvious history of a tick bite or the classic bull’s-eye rash. MRI findings in such cases can include white matter changes and meningeal inflammation that may mimic other conditions.10PubMed Central. Lyme neuroborreliosis: manifestations of a rapidly emerging zoonosis Pediatricians and neurologists in endemic areas increasingly consider Lyme in the differential when a child presents with new seizures that do not fit a typical epilepsy pattern.
Why Diagnosis Is Tricky
Confirming that Lyme disease is the cause of someone’s seizures is harder than confirming Lyme disease itself. Standard two-tier blood testing can tell you whether a person has been exposed to Borrelia, but it cannot tell you whether the bacteria have invaded the central nervous system. The preferred test for proving CNS involvement is an antibody index assay performed on cerebrospinal fluid obtained through a lumbar puncture. This test looks for antibodies produced inside the central nervous system, correcting for the possibility that antibodies simply leaked in from the bloodstream.11PubMed Central. Limitations and Confusing Aspects of Diagnostic Testing for Neurologic Lyme Disease in the United States Even this test, though, has important limitations and must be interpreted alongside the patient’s history, symptoms, and other lab findings.
One significant problem is timing. Early in the course of CNS infection, the immune system may not yet have produced enough antibodies within the cerebrospinal fluid for the test to detect. In a study of children with neuroborreliosis, the absence of cerebrospinal fluid antibodies did not necessarily mean the central nervous system was uninvolved, especially when the spinal tap was done early in the illness.12PubMed. Value of clinical symptoms, intrathecal specific antibody production and PCR in CSF in the diagnosis of childhood Lyme neuroborreliosis For a patient presenting with new seizures and a possible Lyme exposure, a negative early test does not rule out the diagnosis, which can make clinical decision-making genuinely difficult. Newer assays measuring the chemokine CXCL13 in cerebrospinal fluid have shown promise as a supplementary marker.13PubMed. Comparison of the Euroimmun Borrelia ‘antibody index’ with Virotech immunoblot-based detection of intrathecal Borrelia antibody production for the diagnosis of Lyme neuroborreliosis
When Standard Anti-Seizure Drugs Do Not Work
For most seizure disorders, the first line of treatment is anti-seizure medication. But when seizures are driven by an underlying infection or autoimmune process rather than a primary brain abnormality, these medications alone often fall short. The autoimmune epilepsy case report mentioned earlier illustrates this clearly. Both patients had seizures that resisted multiple anti-seizure drugs and worsened when antibiotics were started, a counterintuitive response that may reflect a surge in immune activity triggered by bacterial die-off. Only after immunotherapy was added on top of continued antibiotic treatment did the seizures improve substantially.7PubMed Central. Autoimmune Epilepsy Temporally Associated With Lyme Disease: A Report of Two Cases
This pattern has practical implications. If you or a family member develops new seizures and there is a history or suspicion of tick-borne infection, it is worth asking whether the seizures might have an infectious or autoimmune cause rather than assuming they represent straightforward epilepsy. The treatment pathways diverge significantly. Antibiotics treat the infection itself. Anti-seizure medications control the electrical storms in the brain. But if the real driver is the immune system attacking neural tissue, immunotherapy becomes the critical piece. Getting the diagnosis wrong does not just delay improvement; it can mean months of worsening seizures while clinicians cycle through anti-seizure drugs that were never going to address the root cause.
In cases where Lyme meningitis or encephalitis causes seizures through direct inflammation rather than autoimmunity, appropriate antibiotic treatment of the underlying infection tends to resolve the seizures. A case report described a 55-year-old man admitted with sudden tonic-clonic seizures whose workup revealed neuroborreliosis. Such cases typically improve once the infection is treated.14PubMed Central. Lyme neuroborreliosis: A case report
The Coinfection Problem
Ticks do not carry only Borrelia. A single tick bite can transmit multiple pathogens simultaneously, and some of these co-transmitted organisms have their own capacity to cause neurological disease. Bartonella henselae, better known as the bacterium behind cat-scratch disease, can also be transmitted by ticks and has a well-documented ability to cause encephalopathy. Roughly half of patients with Bartonella-related encephalopathy develop seizures, ranging from brief focal episodes to prolonged status epilepticus, and this may be a relatively common cause of status epilepticus in school-aged children.15Archives of Neurology. Concurrent Infection of the Central Nervous System by Borrelia burgdorferi and Bartonella henselae: Evidence for a Novel Tick-borne Disease Complex
When a patient has both Borrelia and Bartonella infections in the central nervous system, the clinical picture becomes more complex. A case report documented a child with seizures who was found to have Bartonella henselae alongside Babesia species in brain tissue, in a context further complicated by environmental toxin exposure.16PubMed Central. Bartonella henselae, Babesia odocoilei and Babesia divergens-like MO-1 infection in the brain of a child with seizures, mycotoxin exposure and suspected Rasmussen’s encephalitis The takeaway here is not that every Lyme patient has a hidden coinfection, but rather that when seizures appear in the context of a tick-borne illness, a broader infectious workup can be worthwhile. Attributing all neurological symptoms to Borrelia alone may miss a treatable coinfection that is actually driving the seizures.
Can Lyme Disease Cause Lasting Epilepsy
This is the question that worries people most, and the honest answer is that the evidence remains thin. Most reported cases of Lyme-related seizures resolve with treatment, whether through antibiotics, immunotherapy, or both. The concept of “post-infectious epilepsy,” where an infection triggers ongoing seizure susceptibility even after the infection is cleared, is recognized in medicine for other infections like encephalitis caused by herpes simplex virus or certain parasites. Whether Borrelia can do the same thing has not been established in large studies.
The autoimmune epilepsy cases raise an important nuance. If Lyme infection triggers the production of neural autoantibodies, those antibodies could theoretically persist even after the bacteria are eliminated, continuing to provoke seizures. Both patients in the 2025 case report had elevated anti-dopamine receptor antibodies, and their seizures were refractory until immunotherapy was introduced.7PubMed Central. Autoimmune Epilepsy Temporally Associated With Lyme Disease: A Report of Two Cases Whether these patients would have developed chronic epilepsy without immunotherapy, or whether autoantibody production would have eventually stopped on its own, is unknown. The authors themselves emphasized that their findings demonstrate a temporal association, not a proven causal relationship. But the mechanism is biologically plausible: infections are a recognized trigger for autoimmune encephalitis across many different pathogens, and autoimmune encephalitis can produce chronic seizure disorders if untreated.
For now, the safest summary is that Lyme-related seizures can become persistent if the underlying cause, whether infectious or autoimmune, is not identified and treated appropriately. There is no good evidence that properly treated Lyme disease leads to chronic epilepsy in most patients, but the field is working from case reports and small series rather than large epidemiological studies, so confidence in that reassurance has limits.
Differences Between Borrelia Species
Not all Borrelia species cause the same pattern of disease. In Europe, where multiple species circulate, a study comparing Borrelia garinii and Borrelia afzelii in children with neuroborreliosis found notable differences. Children infected with B. garinii showed signs of meningeal irritation more often and had more pronounced cerebrospinal fluid abnormalities compared to those with B. afzelii. Meanwhile, B. afzelii was more frequently associated with the classic skin rash.17PubMed. Lyme Neuroborreliosis in Children: Etiology and Comparison of Clinical Findings of Lyme Neuroborreliosis Caused by Borrelia garinii and Borrelia afzelii In North America, B. burgdorferi sensu stricto is the dominant species, and it tends to produce neurological disease that centers on meningitis and cranial nerve involvement rather than the deeper brain inflammation more commonly seen with some European species.
This geographic and species-level variation means that the risk profile for seizures is not identical everywhere Lyme disease occurs. European patients may face a slightly different spectrum of neurological complications than North American patients, and clinicians in each region calibrate their suspicion accordingly. For a patient or parent reading this from a particular region, the relevant question is which Borrelia species are locally prevalent and what neurological patterns they are known to produce. Your local infectious disease specialist or public health department can usually provide this context.
Lyme-Related Seizures in Animals
If you are a pet owner in a tick-heavy area, you may wonder whether your dog is at risk too. Neurological Lyme disease in dogs is considered rare, but it has been documented. A report described a two-year-old dog that developed persistent tonic convulsions and other neurological signs following a tick bite, with positive Borrelia antibodies in the blood. The neurological symptoms resolved after treatment with high-dose antibiotics.18PubMed. Neurologic abnormalities in two dogs suspected Lyme disease Veterinary neurologists do consider Lyme among the infectious causes of seizures in dogs, particularly in endemic regions, though it ranks below more common causes like idiopathic epilepsy and brain tumors. If your dog develops seizures and has significant tick exposure, mentioning this to your veterinarian is reasonable so that appropriate testing can be considered.