Background
It is well-known that several diseases may lead to diffuse peripheral neuropathy in the autonomic nervous system, including the enteric nervous system, and the sensorimotor system. Since the understanding of enteric neuropathy is limited, it may take time to achieve a correct diagnosis. Signs and symptoms of cardiovascular autonomic neuropathy and sensorimotor neuropathy are more frequently identified, whereas enteric neuropathy with gastrointestinal dysmotility may be categorized as psychological and functional disorders instead of organic neuropathy. Undiagnosed enteric neuropathy may lead to malnutrition and further neurological deterioration.
Objective
The present systematic review aimed to identify mechanisms behind diffuse idiopathic peripheral neuropathies in humans.
Methods
- This review was conducted according to the PRISMA (preferred reporting items for systematic reviews and meta-analysis) statement, with the help of the PRISMA E and E (explanation and elaboration) document.
- A systematic search strategy was used in three databases: PubMed, Embase, and Web of Science.
- Human original and review articles, written in English, illustrating mechanisms behind diffuse peripheral neuropathy verified by objective examinations were intended to be studied.
- Articles that illustrated animal models, drug-induced neuropathy, malnutrition, pain neuropathy, and local neuropathy were excluded.
Results
- In total, 4712 articles were specified. After examining titles and abstracts, 633 were studied in full text. After the removal of articles not fulfilling inclusion or exclusion criteria, 52 were finally included in the review.
- The most frequently described neuropathy was diabetic neuropathy, with a broad range of mechanisms involving mitochondrial dysfunction like oxidative stress and inflammation.
- Microvascular changes in vasculitis and diabetes lead to ischemia and secondary oxidative stress with inflammation.
- Structural changes in neurons and glial cells were observed, with abnormalities in different neurotrophic factors.
- Several ion channels may be involved in painful neuropathy.
Conclusion
Several different mechanisms may be implicated in the development of diffuse peripheral neuropathy involving both internal organs and skin. Screening for metabolic changes autoantibodies should be widely used. Genetic examination of genes coding for ion channels may be assessed to find possible aetiology of idiopathic peripheral neuropathy leading to gastrointestinal dysmotility.