Effect of different management strategies on outcomes in subarachnoid neurocysticercosis: a descriptive, multicentre, retrospective cohort study in the USA

Abstract

Summary Background: Subarachnoid neurocysticercosis (SANCC) is an uncommon but severe form of Taenia solium infection. There is limited evidence to guide clinical management. We aimed to describe the clinical and laboratory features of a cohort of patients with SANCC, and assess the impact of different management strategies on their clinical course. Methods: We performed a multicentre retrospective cohort study with patients from 15 medical centres across nine states in the USA. SANCC was defined based on histopathology; the presence of cysts in the basilar subarachnoid spaces/sylvian fissures/spine with antibody positivity to T. solium/meeting Del Brutto criteria; or inflammatory cerebrospinal fluid (CSF) with positivity to T.solium antigen or qPCR and negativity to viral, fungal, and bacterial pathogens. Each site reported up to the most recent 7 sequential patients with SANCC based on institutional memory or systematic searching of the electronic medical records. Data entry was performed from Nov 12, 2021 to Nov 28, 2022. Minimal criteria for inclusion was a discharge summary for a hospitalisation due to SANCC. Data collection centred around the earliest hospitalisation associated with the SANCC. Data from prior and subsequent inpatient and outpatient visits were also collected. Data were analysed to assess the impact of treating with anthelmintics based on CSF biomarkers, the normalisation of imaging, or a fixed duration on SANCC recurrence rates. Diagnostic delay was defined as patients with prior hospitalisation or extensive workup for a complication (e.g. stroke, hydrocephalus, meningitis, mass) but without SANCC suspected. Those with a diagnostic delay and those with a diagnosis of SANCC but were initially managed without anthelmintics (e.g. shunt, cyst removal) were considered to have a delay in anthelmintic treatment. The effect of delay in anthelmintic treatment on subsequent Emergency Room visits and hospitalisations was assessed. Findings: Data were collected on 75 patients with neurocysticercosis. Of whom, six patients were determined to not meet the definition of SANCC and were excluded; ultimately, 69 (40 male, 29 female) met the definition of SANCC. The year of case-defining SANCC hospitalisation ranged from 2009 to 2022, with a median year of 2016. Median 2.5 years, interquartile range (IQR) 0.94–4.0 years. SANCC was a new diagnosis in 59 patients. Of these, 18 (31%) had prior medical visits for SANCC manifestations (i.e. hydrocephalus [17%], stroke [5%], and/or meningitis [7%], brain mass [3.3%], TIA [1.6%], or intracranial hypertension without hydrocephalus [1.6%]) but SANCC was not considered. At the time of discharge, 9 (13%) patients were not given albendazole and/or praziquantel due to cost or availability. 52 patients had >60 of post-hospitalisation follow-up and completed the intended course of therapy. Use of CSF T. solium biomarkers (antigen [TsAg] and/or qPCR) to guide length of anthelmintic therapy decreased SANCC recurrence (0 [n = 0 of 17] vs. 23% [n = 8 of 33], p = 0.039, odds ratio [OR] 95% confidence interval [CI] 0.0–0.84), whereas use of magnetic resonance imaging normalisation to guide treatment length did not decrease recurrence (15% [n = 3 of 20] vs 16.67% [n = 5 of 30] p > 0.9, OR 95% CI 0.21–4.18). A delay in anthelmintic treatment was associated with an increase in subsequent SANCC-related Emergency Department visits or hospital admissions (median 1, IQR 1–2) compared to no anthelmintic delay (median 0.5, IQR 0–1; p = 0.018). Interpretation: SANCC is commonly misdiagnosed and diagnostic and therapeutic delays may lead to more subsequent hospital encounters for SANCC-related problems. Use of CSF Ts biomarkers to guide anthelmintic therapy may decrease SANCC recurrence. However, given the small sample size, adjustment for confounders with regression analysis was not performed and we cannot exclude confounding as responsible for differences seen. Larger, prospective studies are needed to confirm these findings. Funding: Division of Intramural Research, National Institute of Allergy and Infectious Diseases.