Prevalence of Cervical Lymphadenopathy in Acute CNS Infections – Testing Glymphatics in Humans

BACKGROUND: Glymphatics in the brain have recently been shown to drain cervical lymph nodes in animal models. Diagnosis of acute central nervous system (CNS) infections is limited by pauci-microbial nature of the cerebrospinal fluid (CSF). Evaluation of cervical lymphadenopathy in acute CNS infections may aid in diagnosis and provide evidence of glymphatics. OBJECTIVE: To study the prevalence of cervical lymphadenopathy in acute CNS infections and to assess diagnostic yield by using cervical lymphadenopathy biopsy/FNAC. DESIGN, SETTING AND PARTICIPANTS: A cross-sectional study was conducted in a tertiary care hospital in India where adults (≥18 years) with acute CNS infections were recruited. They were clinically and radiologically (ultrasound) screened for cervical lymphadenopathy. Biopsy (surgical/FNAC) was carried in feasible cases and samples were sent for histopathology and culture. RESULTS: One hundred and five patients with acute CNS infections were enrolled for the study with tuberculous meningitis (TBM) being the most common (33%). 28.6% (30/105) of cases had cervical lymphadenopathy, of which only six patients met the criteria for biopsy. FNAC/biopsy of cervical nodes resulted in increase in definite microbiological/histopathological evidence of CNS infections by 25%. CONCLUSIONS: Prevalence of cervical lymphadenopathy in patients with acute CNS infections was 28.6% suggesting the presence of glymphatics. USG neck increased detection of abnormal cervical nodes that were not clinically palpable. Tissue diagnosis of cervical lymphadenopathy improved real-time diagnostic yield of acute CNS infections especially TBM.