Non-infectious meningitis and CNS demyelinating diseases: A conceptual review.

Many cases of aseptic meningitis or meningoencephalitis, unresponsive to antimicrobial treatments, have been reported recently in patients with established/new-onset central nervous system (CNS) inflammatory demyelinating diseases (CNSIDDs). Given the higher probability of infectious etiologies, CNSIDDs are rarely considered among the differentials in meningitis or meningoencephalitis cases. We gathered and tabulated cases of non-infectious, steroid-responsive meningitis or meningoencephalitis associated with neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein-associated disease (MOGAD). This conceptual review highlights the need to bolster routine infectious workups with immunological workups in cases of meningoencephalitis or meningitis where potential autoimmune etiologies can be suspected. Although differentiating CNSIDDs with meningeal involvement from infectious meningitis may not substantially affect acute treatment strategies, long-term management and follow-up of the two are entirely different. We also discuss future research directions and hypotheses on how CNSIDDs may be associated with meningitis-like presentations, e.g. overlapping glial fibrillary acidic protein astrocytopathy or autoimmune encephalitis, alterations in regulatory T-helper cells function, and undetected viral agents.

Soil heavy metals are associated with the distribution of multiple sclerosis in Isfahan, Iran.

BACKGROUND: Few epidemiological studies have explored the effects of soil pollution on multiple sclerosis (MS) risk in Asia. METHOD: Based on catchment areas, Isfahan province is divided into five regions (Central, North, East, West, and South), and Soil sampling performed in catchment area with the highest range of MS prevalence and incidence. Samples were analyzed for cobalt (Co), lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), and absorbable forms of Pb, Cd, and Co. Linear regression is used to examine the association of soil heavy metals with prevalence of MS in central part of Isfahan province. RESULT: Multiple sclerosis prevalence ranged from 5.62 to 156.65 in different townships. Based on regression analysis, in case of considering fixed amounts for the rest of elements, a one (SD) increase of absorbable Pb and absorbable Cd are associated with 0.385 (SD) (P < 0.0001) increase and 0.209 (SD) (P < 0.007) decrease in MS prevalence, respectively. CONCLUSION: This study documented a significant association between exposure to absorbable Pb and Cd in soil with prevalence of MS in Isfahan. Further work is warranted to confirm this association and if validated, to understand the mechanisms behind the association.