Supplementary Material for: Lyme Neuroborreliosis Presenting With Isolated Intracranial Hypertension: A Case Report

Background:
Lyme borreliosis (LB), a tick-borne illness caused by Borrelia burgdorferi, is increasingly prevalent in Nova Scotia (NS), Canada, which has the highest incidence in North America. While most cases present as early localized disease, approximately 20% develop early disseminated disease, which can include neurological symptoms, an entity called Lyme neuroborreliosis (LNB). This case report describes an unusual LNB presentation with isolated intracranial hypertension (IH).
Case Presentation:
A 6-year-old female presented to our pediatric hospital with binocular horizontal diplopia, headache, fever, malaise and suspected papilledema 47 days after an embedded tick bite. A diagnosis of Lyme disease had been made 10 days prior in the community based on positive serologies and erythema migrans, but she developed a Jarisch-Herxheimer reaction within 24h of oral doxycycline, leading to an antibiotic change to amoxicillin. During the hospital admission, an ophthalmological examination revealed papilledema and intracranial hypertension was evidenced by an opening pressure of 36 mmHg and brain MRI findings. The lumbar puncture revealed pleocytosis and positive cerebrospinal fluid antibodies for Borrelia. The patient was initially treated with two days of ceftriaxone, followed by a 12-day outpatient course of doxycycline for LNB. High doses of acetazolamide (500mg TID) were needed to achieve symptom control. Two months after her hospital discharge there was resolution of papilledema and the acetazolamide was weaned.
Conclusion:
This case highlights the importance of considering Lyme disease in the differential diagnosis of IH, particularly in endemic regions. Early recognition, diagnostic workup, and appropriate treatment are crucial for optimal outcomes in LNB.