Background: Charcot-Marie-Tooth disease (CMT) is the most common inherited neuropathy. CMT is classified into 2 main subgroups: CMT type 1 (CMT1; demyelinating form) and CMT type 2 (CMT2; axonal form). The objectives of this study were to systematically review and assess the quality of studies reporting the incidence and/or prevalence of CMT worldwide. Summary: A total of 802 studies were initially identified, with only 12 meeting the inclusion criteria. CMT prevalence was reported in 10 studies and ranged from 9.7/100,000 in Serbia to 82.3/100,000 in Norway. The frequency of the main subtypes varied from 37.6 to 84% for CMT1 and from 12 to 35.9% for CMT2; the country with the lowest prevalence of CMT1 was Norway, and the country with the highest prevalence of CMT1 was Iceland; on the other hand, CMT2 was least prevalent in the United Kingdom and most prevalent in Norway. Key Messages: This review reveals the gaps that still exist in the epidemiological knowledge of CMT around the world. Published studies are of varying quality and utilise different methodologies, thus precluding a robust conclusion. Additional research focusing on epidemiological features of CMT in different nations and different ethnic groups is needed.

Since its first isolation in 1844, usnic acid [2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzo-furandione] has become the most extensively studied lichen metabolite and one of the few that are commercially available. Lichens belonging to usnic acid-containing genera have been used as crude drugs throughout the world. There are indications of usnic acid being a potentially interesting candidate for such activities as anti-inflammatory, analgesic, healing, antioxidant, antimicrobial, antiprotozoal, antiviral, larvicidal and UV protection. However, some studies reported the liver toxicity and contact allergy. Thus, further studies are needed to establish the efficacy and safety of usnic acid