Can Lyme Disease Cause a False Brain Tumor (Pseudotumor Cerebri)?

A “false brain tumor,” also known as pseudotumor cerebri, can cause severe headaches, blurred vision, and increased pressure in the brain—without an actual tumor.

Patients often fear a brain tumor when symptoms begin—but imaging may be normal.

In rare cases, Lyme disease can trigger this condition, especially in children.

For a broader overview of nervous system involvement, see neurologic Lyme disease.

What Is a False Brain Tumor?

Pseudotumor cerebri, often called a “false brain tumor,” is a condition where pressure builds inside the skull without an actual tumor being present.

Symptoms can mimic a brain tumor, including headaches, blurred vision, and sensitivity to light or sound.

Can Lyme Disease Cause Increased Brain Pressure?

Yes. Lyme disease affecting the nervous system, known as neuroborreliosis, can lead to increased intracranial pressure, which may present as pseudotumor cerebri.

While uncommon, this presentation is important because it may be the only sign of central nervous system infection.

Case: Child With a False Brain Tumor Due to Lyme Disease

Although pseudotumor cerebri has many causes, infections such as Lyme disease should be considered—especially in children with unexplained neurologic symptoms.

Ezequiel and colleagues described the case of a 9-year-old boy with pseudotumor cerebri due to Lyme disease.¹

The boy was admitted with daily pulsatile frontotemporal headaches, pallor, sensitivity to light, and sensitivity to sound. He did not have vomiting, nighttime awakening, or visual changes.

Doctors identified papilloedema (swelling of the optic disc), but a CT scan of the head was normal.

A spinal tap revealed elevated opening pressure, indicating increased pressure in the cerebrospinal fluid.

How Lyme Disease Was Diagnosed

Diagnosis required both blood testing and spinal fluid evaluation to confirm infection of the nervous system.

The boy lived in Portugal and had recently visited the countryside before symptoms began.

Because of this exposure history, he was tested for Lyme disease. Western blot testing and spinal fluid evaluation were positive.

He was diagnosed with Lyme neuroborreliosis and treated with a 21-day course of intravenous ceftriaxone.

The child recovered completely.

Why This Diagnosis Can Be Missed

Pseudotumor cerebri is often evaluated as a neurologic or ophthalmologic condition. Lyme disease may not be considered if there is no known tick bite, rash, or classic presentation.

But Lyme disease can present with neurologic symptoms, and increased intracranial pressure may be the key clue.

For more on diagnostic challenges, see why Lyme tests can be negative.

FAQ: Lyme Disease and False Brain Tumors

Can Lyme disease cause a false brain tumor?
Yes. In rare cases, Lyme disease can lead to increased intracranial pressure, resulting in pseudotumor cerebri.

What are symptoms of pseudotumor cerebri?
Symptoms may include headache, blurred vision, light sensitivity, sound sensitivity, and signs of increased pressure in the brain.

Is a “fake brain tumor” the same as pseudotumor cerebri?
Yes. The term “fake brain tumor” is sometimes used to describe pseudotumor cerebri, where symptoms resemble a tumor but no tumor is present.

Clinical Takeaway

Lyme disease should not be overlooked in children with unexplained pseudotumor cerebri or increased intracranial pressure—especially when standard evaluations are unrevealing.

As with other neurologic presentations of Lyme disease, the pattern of symptoms may be more important than any single test result.

Early recognition and appropriate antibiotic treatment can lead to complete recovery.

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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