By Laura Munoz-Arcos, MD
Johns Hopkins Transverse Myelitis Center, Baltimore, MD
Since January 2016, researchers from the Johns Hopkins Transverse Myelitis Center have focused their attention towards the emergence of neurological complications associated with the Zika virus in Latin America and the Caribbean. The Zika virus was discovered in the 1950s in Africa where it was documented to cause a mild-febrile illness with no neurological complications described. Little to no information regarding the virus was available until 2007 when the Zika virus caused the first epidemic of infection in the Yap Islands. In 2013, the Zika virus led to a similar outbreak of illness in French Polynesia and the medical community was advised about the risk of developing neurological disorders secondary to this viral infection. In fact, in 2015 when the Zika virus reached the Americas, neurological complications such as Guillain-Barré syndrome (GBS) and microcephaly were observed. The temporal relationship of the Zika infection outbreak and the emergence of such neurological problems suggested a possible link between them.
GBS is described as a post-infectious disorder which affects the nerves that are responsible for movement, sensory functions and even vital functions, such as the beating of the heart and breathing. Frequently, GBS is confused with TM and vice versa. Clinically, patients with GBS present with a rapidly progressive ascending paralysis that commonly starts in the lower extremities and in a matter of days or weeks ascends and can potentially involve the respiratory muscles. Even though GBS has the strongest evidence of a link with Zika virus infections, other neurological disorders, such as myelitis and encephalitis have also been described in adults affected by the infection.
As part of our studies, researchers from the Johns Hopkins TM Center, and investigators and health care providers in South America established a collaborative network known as Neuroviruses Emerging in the Americas Study (www.neasstudy.org). NEAS is a multi-center study looking to combine the efforts of researchers, health care providers and patients in the Americas to establish a comprehensive registry of the clinical, radiological and laboratory profile of patients with new onset of neurological disorders associated with Zika virus infections, including GBS, myelitis, encephalitis and acute disseminated encephalomyelitis (ADEM). The purpose of our study is to determine whether there is a causal relationship between Zika virus infections and neurological complications in adults, as well as the underlying mechanisms which can help in the development of treatments, and prevention strategies, such as vaccines.