Inflammation From Peripheral Organs to the Brain: How Does Systemic Inflammation Cause Neuroinflammation?
- 1Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Osaka, Japan
- 2Addiction Research Unit, Osaka Psychiatric Research Center, Osaka Psychiatric Medical Center, Osaka, Japan
As inflammation in the brain contributes to several neurological and psychiatric diseases, the cause of neuroinflammation is being widely studied. The causes of neuroinflammation can be roughly divided into the following domains: viral infection, autoimmune disease, inflammation from peripheral organs, mental stress, metabolic disorders, and lifestyle. In particular, the effects of neuroinflammation caused by inflammation of peripheral organs have yet unclear mechanisms. Many diseases, such as gastrointestinal inflammation, chronic obstructive pulmonary disease, rheumatoid arthritis, dermatitis, chronic fatigue syndrome, or myalgic encephalomyelitis (CFS/ME), trigger neuroinflammation through several pathways. The mechanisms of action for peripheral inflammation-induced neuroinflammation include disruption of the blood-brain barrier, activation of glial cells associated with systemic immune activation, and effects on autonomic nerves via the organ-brain axis. In this review, we consider previous studies on the relationship between systemic inflammation and neuroinflammation, focusing on the brain regions susceptible to inflammation.
Lyme/MSIDS also causes peripheral nervous system inflammation. Once borrelia enter the cerebrospinal fluid (CSF), they elicit an inflammatory response. This study states about 15% of patients with Lyme disease develop peripheral and central nervous system involvement, although I suspect it’s much, much higher. It also states inflammation plays a causal role in the array of neurologic changes associated with Lyme disease.