Proportion of confirmed Lyme neuroborreliosis cases among patients with suspected early European Lyme neuroborreliosis

Abstract

Purpose: To determine the frequency of confirmed Lyme neuroborreliosis (LNB) cases in adult patients with three different clinical presentations consistent with early LNB.

Methods: Data were obtained through routine health care at the UMC Ljubljana, Slovenia from 2005-2022, using clinical pathways. The patients were classified into three groups: i) radicular pain of new onset (N = 332); or ii) involvement of cranial nerve(s) but without radicular pain (N = 997); or iii) erythema migrans (EM) skin lesion(s) in conjunction with symptoms suggestive of nervous system involvement but without either cranial nerve palsy or radicular pain (N = 240). The diagnosis of LNB considered the following variables: the presence of: 1) neurologic symptoms consistent with LNB (with no other obvious explanation); 2) cerebrospinal fluid (CSF) pleocytosis (> 5×10⁶ leukocytes/L); and 3) demonstration of intrathecal synthesis of borrelial antibodies, and/or cultivation of borrelia from CSF, and/or the presence of EM. Patients fulfilling only the first two criteria were interpreted as having possible LNB, while those who satisfied all three criteria were regarded as having confirmed LNB.

Results: Of 1569 adult patients, 348 (22.2%) had confirmed LNB and 70 (4.5%) others had possible LNB. The proportion of confirmed LNB cases was the highest for patients with radicular pain (217/332, 65.4%), followed by the group with EM and neurologic symptoms (47/240, 19.6%), and those with cranial neuritis (84/997, 8.4%).

Conclusion: Only 22% of patients evaluated had confirmed LNB. The proportion of confirmed LNB cases correlated with clinical presentation and was highest among patients with recent onset of radicular pain.

Keywords: Bannwarth syndrome; Borrelia culture from cerebrospinal fluid; Borrelial meningitis; Cranial neuritis; Intrathecal borrelial antibody synthesis; Lyme neuroborreliosis.

Figure 1:. Flow chart of inclusion of patients with possible and confirmed Lyme neuroborreliosis at UMC Ljubljana in Slovenia, 2005–2022

^aWithout other obvious reason. ^bExcluded due to concomitant TBE (two patients with radicular pain of recent onset, one patient with cranial neuritis and four patients with erythema migrans and neurologic symptoms other than radicular pain or cranial nerve dysfunction). Abbreviations: LNB, Lyme neuroborreliosis; PFP, peripheral facial palsy; EM, erythema migrans; CSF, cerebrospinal fluid; TBE, tick-borne encephalitis; ITBAS, intrathecal borrelial antibody synthesis.