Can Lyme Disease Cause Encephalitis?

Lyme neuroborreliosis can rarely lead to encephalitis.
A 74-year-old woman was hospitalized four times before diagnosis.
MRI findings and spinal fluid testing confirmed CNS involvement.

Lyme neuroborreliosis can rarely present with encephalitis, confusion, psychiatric symptoms, and MRI abnormalities.

A 74-year-old woman had been hospitalized four times over a period of three months. During these admissions, she was treated with antibiotics for a urinary tract infection, states Rosendahl and colleagues in their article “Lyme neuroborreliosis with encephalitis: A rare case.”¹

On her last admission, the woman exhibited confusion, paranoid delusions, a weight loss of 33 lbs., back pains, history of fever and vomiting suspect of cancer and infection of unknown origin, leading doctors to suspect she suffered from a central nervous system (CNS) infection.

Lyme Neuroborreliosis With Encephalitis

“We present a case of Lyme neuroborreliosis with encephalitis with significant parenchymal inflammation on magnetic resonance imaging (MRI) in an immunosuppressed patient.”

A lumbar puncture was performed and she began empirical treatment for bacterial meningitis and viral encephalitis, which included benzylpenicilline, ceftriaxone, aciclovir and dexamethasone.

The woman reportedly had no history of a tick bite or an erythema migrans (EM) rash or painful meningoradiculitis. However, approximately 3 months earlier she was treated for a universal skin rash.

MRI Findings Confirmed CNS Involvement

“An MRI showed hyperintensities in basal ganglia, thalami, medial temporal lobes and mesencephalon and hereby confirmed the diagnosis of [Lyme neuroborreliosis] encephalitis,” according to the authors.

The woman was treated successfully with intravenous ceftriaxone and oral doxycycline for Lyme neuroborreliosis.

“Follow-up brain MRI showed complete remission of previous hyperintensities in basal ganglia and thalamus,” the authors state.

“At 6 months follow-up, the patient had improved but still reported some memory problems.”

Clinical Perspective

This case highlights how Lyme neuroborreliosis may rarely present with encephalitis, psychiatric symptoms, weight loss, and MRI abnormalities—particularly in immunosuppressed patients.

The absence of a known tick bite or erythema migrans rash may delay diagnosis.

For more neurologic complications, see neurologic Lyme disease and Lyme neuroborreliosis.

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