Hippocampal Metabolic Alterations and Cognitive Dysfunction in Varicella Zoster Virus Meningitis: A Single-Center Case Series Study

BACKGROUND: Meningitis has been found to be associated with dementia. Different pathogens of meningitis lead to different cognitive impairments. However, the change of cognitive function and cellular metabolism in the hippocampus in varicella zoster virus (VZV) meningitis has received little attention. We aimed to explore the cognitive function and changes of cellular metabolism in bilateral hippocampal regions in VZV meningitis. MATERIAL/METHODS: We used magnetic resonance spectroscopy to check the cellular metabolism in the bilateral hippocampal region in 23 VZV meningitis patients and 19 controls in our hospital from June 2020 to November 2022. Also, cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) scale, and the correlation between MoCA scores and cellular metabolism in the bilateral hippocampal region was analyzed. RESULTS: Six (26.1%) of the 23 patients with VZV meningitis had cognitive decline. Compared with that of the control group, the MoCA scores of VZV meningitis patients was much impaired (25.88±2.31 vs 27.74±1.94, P<0.05), visual-spatial executive function and delayed recall were significantly decreased (P<0.05), and N-acetylaspartate (NAA)/creatine (Cr) ratios in the bilateral hippocampus of patients with VZV meningitis were significantly lower (P<0.05). NAA/Cr ratios in the left and right hippocampus were positively correlated with MoCA scores (r=0.4158, P=0.0385; r=0.5274, P=0.0010, respectively), and negatively correlated with white blood cell count (P<0.01) and protein content in cerebrospinal fluid (P<0.05). CONCLUSIONS: Patients with VZV meningitis had cognitive dysfunction and altered cellular metabolism of bilateral hippocampal regions. The main cognitive abnormalities were visual-spatial executive function and delayed recall.