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.