Can Lyme Disease Cause a False Brain Tumor? A Child’s Case of Pseudotumor Cerebri

A rare neurologic complication of Lyme disease
Pseudotumor cerebri can mimic a brain tumor without an actual mass
Prompt diagnosis and treatment can lead to full recovery

Can Lyme disease cause a false brain tumor? Although rare, Lyme neuroborreliosis can lead to pseudotumor cerebri, a condition in which increased pressure around the brain causes headaches, papilledema, blurred vision, double vision, and other symptoms despite the absence of a true brain tumor. Pseudotumor cerebri is often used interchangeably with idiopathic intracranial hypertension (IIH). However, when Lyme disease is responsible, it represents a form of secondary intracranial hypertension because an underlying cause has been identified. This pediatric case highlights why Lyme disease should remain in the differential diagnosis of children with unexplained intracranial hypertension, even in regions where Lyme disease is considered uncommon.

This case, first reported by Ezequiel and colleagues in BMJ Case Reports, describes a 9-year-old boy whose only manifestation of Lyme neuroborreliosis was pseudotumor cerebri—a condition often referred to as a “false brain tumor.” The report illustrates how Lyme disease can rarely present with increased intracranial pressure despite normal brain imaging.¹

Symptoms can mimic a brain tumor

The 9-year-old boy was admitted to the hospital with “daily pulsatile frontotemporal headache, pallor, photophobia and phonophobia, without night awakening, vomiting or visual changes,” the authors wrote.

Photophobia refers to sensitivity to light, while phonophobia describes intolerance or sensitivity to sound. These symptoms are commonly associated with increased intracranial pressure but can also occur with migraines and other neurologic disorders.

His neurological examination revealed papilledema, or swelling of the optic nerve, but no neck stiffness or other focal neurologic abnormalities. A CT scan of the head was normal.

A lumbar puncture demonstrated an elevated opening pressure of 50 cm H₂O along with lymphocytic pleocytosis, indicating increased intracranial pressure accompanied by inflammation. MRI of the brain was normal.

What is pseudotumor cerebri?

Pseudotumor cerebri is a syndrome caused by elevated cerebrospinal fluid pressure surrounding the brain without evidence of a brain tumor. Patients often experience headaches, papilledema, transient visual disturbances, nausea, and occasionally double vision. Some patients also develop a sixth cranial nerve palsy, which can produce horizontal double vision because of impaired eye movement. If left untreated, prolonged pressure on the optic nerves can result in permanent vision loss.

In this child, the inflammatory changes associated with Lyme neuroborreliosis likely interfered with normal cerebrospinal fluid absorption, leading to elevated intracranial pressure despite otherwise normal brain imaging.

The boy was started on acetazolamide, a carbonic anhydrase inhibitor commonly used to reduce cerebrospinal fluid production and lower intracranial pressure while additional testing was underway.

Extensive testing for bacterial and viral infections was otherwise negative.

Diagnosis of Lyme neuroborreliosis

Because the child had traveled to the French Pyrenees and rural areas before becoming ill, the physicians considered Lyme disease despite living in Portugal, where Lyme disease is relatively uncommon.

Serologic testing by ELISA followed by Western blot was positive for Borrelia burgdorferi. Cerebrospinal fluid antibody testing and Western blot were also positive, confirming the diagnosis of Lyme neuroborreliosis.

The absence of a recalled tick bite or erythema migrans rash did not exclude Lyme disease. As the authors noted, many European patients with neuroborreliosis do not remember a tick bite or develop the classic rash.

For a broader discussion of nervous system involvement, see Lyme neuroborreliosis.

Treatment for Lyme neuroborreliosis

The boy received a 21-day course of intravenous ceftriaxone for Lyme neuroborreliosis. His headaches resolved completely, papilledema disappeared, and he remained symptom-free during nine months of follow-up.

This favorable outcome highlights the importance of recognizing Lyme disease early in patients with unexplained intracranial hypertension. Prompt treatment may prevent permanent neurologic or visual complications.

The authors emphasized an important clinical lesson:

“CSF changes are not common, so in their presence, it is compulsory to investigate an infectious origin, as happened in this case, as the intracranial hypertension might be the only symptom of a central nervous system infection.”

They further concluded:

“Borrelia infections should be actively investigated in children with central nervous system disease even in non-endemic areas.”

Can pseudotumor cerebri occur in adults with Lyme disease?

Although most reported cases involve children, physicians should recognize that this complication has also been documented in adults.

A 2020 case report described a 51-year-old woman with chronic headache and Lyme neuroborreliosis who developed papilledema, visual impairment, and markedly elevated intracranial pressure.²

Her lumbar puncture showed an opening pressure of 500 mm H₂O, lymphocytic pleocytosis, elevated protein, and Borrelia burgdorferi-specific antibodies in the cerebrospinal fluid. MRI findings included meningeal enhancement and distention of the optic nerve sheaths, both of which supported increased intracranial pressure.

She was treated with intravenous ceftriaxone and acetazolamide. Because her symptoms continued to worsen, she also required repeated therapeutic lumbar punctures and eventually placement of a ventriculoperitoneal shunt to lower the intracranial pressure.

Her headache, neck pain, nausea, and vomiting resolved, but she was left with optic nerve atrophy, loss of color vision, and a central blind spot. The case illustrates why delayed recognition of intracranial hypertension can lead to permanent visual complications even after the underlying infection is treated.

How common is pseudotumor cerebri in Lyme disease?

Pseudotumor cerebri appears to be a rare manifestation of Lyme neuroborreliosis. In their review, the authors of the adult case identified only five previously published adult cases but found 35 reported pediatric cases involving children between 4 and 14 years of age.²

The true frequency remains uncertain. Because symptoms such as headache, nausea, light sensitivity, blurred vision, double vision, head pressure, and a feeling of fullness in the head can overlap with more common neurologic disorders, some cases may initially be attributed to migraine, idiopathic intracranial hypertension, or other conditions.

The exact mechanism remains uncertain. One proposed explanation is that inflammation involving the meninges and arachnoid villi interferes with normal cerebrospinal fluid absorption, allowing pressure to build around the brain.

Why papilledema requires prompt evaluation

Papilledema is swelling of the optic disc caused by increased pressure within the skull. It may occur before a patient notices significant visual symptoms. For that reason, a normal CT or MRI does not rule out clinically important intracranial hypertension.

Evaluation may include a detailed neurologic and ophthalmologic examination, brain imaging, and lumbar puncture when appropriate. When inflammatory cells or other abnormalities are present in the cerebrospinal fluid, physicians should consider infectious and inflammatory causes rather than assuming the condition is idiopathic.

Lyme disease is only one possible cause. The differential diagnosis may also include other infections, cerebral venous sinus thrombosis, medications, endocrine disorders, nutritional abnormalities, and systemic diseases.

For more information about headache patterns associated with Lyme disease, see Can Lyme Disease Cause Headaches?

Questions addressed in this podcast

1. What is pseudotumor cerebri, and why is it referred to as a false brain tumor?
2. What causes pseudotumor cerebri, and how is it diagnosed?
3. How often does pseudotumor cerebri occur in Lyme disease?
4. Can pseudotumor cerebri be the only manifestation of Lyme disease?
5. Why was the child initially treated with acetazolamide?
6. What are the considerations surrounding treatment for Lyme neuroborreliosis?

Thanks for listening to another Inside Lyme Podcast. You can read more about these cases in my show notes and at DanielCameronMD.com. As always, your likes, comments, reviews, and shares help spread the word about Lyme disease. Until next time on Inside Lyme.

Please remember that the advice given is general and is not intended as specific medical advice for any particular patient. If you require individual medical advice, please consult an experienced healthcare professional.

Frequently Asked Questions

Can Lyme disease cause a false brain tumor?

Yes, although it is rare. Lyme neuroborreliosis can cause secondary intracranial hypertension, producing headaches, papilledema, visual symptoms, and elevated cerebrospinal fluid pressure without an actual brain tumor.

Can Lyme disease be mistaken for a brain tumor?

Yes. Severe headache, papilledema, visual symptoms, and elevated intracranial pressure can initially raise concern for a brain tumor until imaging and further testing identify another cause, such as Lyme neuroborreliosis.

What is the difference between pseudotumor cerebri and a brain tumor?

A brain tumor is an abnormal mass of tissue. Pseudotumor cerebri causes symptoms that resemble those of a brain tumor because pressure is elevated inside the skull, but imaging does not reveal a tumor or other mass.

Can Lyme disease cause head pressure or a feeling of fullness in the head?

Lyme disease can be associated with headaches and, rarely, increased intracranial pressure. Some patients may describe this as head pressure or a feeling of fullness in the head. However, these symptoms have many possible causes and should not automatically be attributed to Lyme disease without an appropriate medical evaluation.

Can Lyme disease cause papilledema?

Yes, in rare cases involving intracranial hypertension. Papilledema is swelling of the optic disc caused by increased pressure within the skull and requires prompt evaluation because prolonged pressure can damage vision.

Can pseudotumor cerebri be the only sign of Lyme disease?

It can be the presenting or dominant manifestation of Lyme neuroborreliosis. In the pediatric case, the child did not recall a tick bite or rash and had few other signs of central nervous system infection.

Can Lyme disease cause pseudotumor cerebri in adults?

Yes, but adult cases appear to be especially uncommon. Published reports describe adults with headache, papilledema, elevated cerebrospinal fluid pressure, and evidence of Lyme neuroborreliosis.

How is Lyme-related intracranial hypertension treated?

Treatment may include antibiotics for Lyme neuroborreliosis and medications such as acetazolamide to lower intracranial pressure. Some patients may also require therapeutic lumbar punctures or, rarely, a surgical shunt when pressure remains dangerously elevated.

Clinical Takeaway

Lyme neuroborreliosis should be considered in children or adults with unexplained intracranial hypertension, particularly when cerebrospinal fluid shows inflammatory changes or there is a history of possible tick exposure.

The absence of a known tick bite, erythema migrans rash, neck stiffness, or abnormal brain imaging does not exclude the diagnosis.

Although rare, pseudotumor cerebri is an important and potentially reversible neurologic manifestation of Lyme disease. Recognizing it early may prevent permanent vision loss.

Related Articles

Can Lyme Disease Cause Brain Inflammation?
Can Lyme Disease Cause Brain Lesions?
Lyme Disease Symptoms Guide
Pediatric Lyme Disease
Why Lyme Disease Is Often Misdiagnosed

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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