Zika virus (ZIKV) is now considered an emerging flavivirosis, with a first large outbreak registered in the Yap Islands in 2007. In 2013, a new outbreak was reported in the French Polynesia, with associated cases of neurological complications including Guillain-Barré syndrome (GBS). The incidence of GBS has increased in Brazil since 2015, what is speculated to be secondary to the ZIKV infection outbreak. The gold-standard test for detection of acute ZIKV infection is the polymerase-chain reaction technique, an essay largely unavailable in Brazil. The diagnosis of GBS is feasible even in resource-limited areas using the criteria proposed by the GBS Classification Group, which is based solely on clinical grounds. Further understanding on the relationship of ZIKV with neurological complications is a research urgency.

Multiple Sclerosis is a chronic inflammatory demyelinating disease that affects 2.5 million people in the world. NEDA (No evidence of disease Activity) -4 is a new concept related to absence of disease activity in the context of MS. It takes into account the following four parameters: relapses; disability progression; lesion load and brain atrophy. Areas covered: The purpose of this paper is to visit the new emerging concepts of NEDA. Although it is considered important and attractive, there is a lack of uniformity. Expert commentary: Although NEDA-4 embraces important markers of disease activity and degeneration, this definition is still evolving and other parameters apart from the loss of brain volume might be included, especially those related to disability, such as cognitive problems, visual function, fatigue and pain.