A possible association of Zika virus to acute disseminated encephalomyelitis (ADEM) was reported by Maria Lucia Brito Ferreira, MD, with Restoration Hospital in Recife, Brazil. ADEM is an autoimmune disorder that attacks the brain’s myelin, similar to multiple sclerosis.
“Though our study is small, it may provide evidence that in this case the virus has different effects on the brain than those identified in current studies,” said Ferreira. “Much more research will need to be done to explore whether there is a causal link between Zika and these brain problems.”
From December 2014 to June 2015, researchers followed people who came to the hospital in Recife with symptoms compatible with arboviruses, the family of viruses that includes Zika, dengue, and chikungunya. The authors saw 151 cases with neurological manifestations from December 2014 to December 2015. Six people developed neurologic symptoms consistent with autoimmune disorders and underwent exams and blood tests.
All patients presented to the hospital with fever followed by a rash. Some also had severe itching, myalgia, arthralgia, and red eyes. The neurologic symptoms began immediately for some people and up to 15 days later for others.
Of the six people who had neurologic problems, two developed acute disseminated encephalomyelitis (ADEM), a swelling of the brain and spinal cord that attacks the myelin. In both cases, MRI brain scans showed white matter lesions. Unlike MS, ADEM usually consists of a single attack that most people recover from within six months. In some cases, the disease can reoccur. Four of the people developed Guillain-Barré syndrome, another syndrome involving myelin.
After discharge, five of the six patients continued to have motor function problems. One person had vision problems and one had problems with memory and thinking skills.
The participants all tested positive for Zika virus and negative for dengue and chikungunya.
“This doesn’t mean that all people infected with Zika will experience these brain problems. Of those who have nervous system problems, most do not have brain symptoms,” said Ferreira. “However, our study may shed light on possible lingering effects the virus may be associated with in the brain.”
“This is the tip of the iceberg,” stated Ferriera. “But we have to see beyond this. There are a lot of things to be discovered, such as neurological components of this infection.”
“At present, it does not seem that ADEM cases are occurring at a similarly high incidence as the GBS cases, but these findings from Brazil suggest that clinicians should be vigilant for the possible occurrence of ADEM and other immune-mediated illnesses of the central nervous system,” said James Sejvar, MD, with the Centers for Disease Control and Prevention.
From materials presented at AAN Annual Meeting, Vancouver, British Columbia. Emerging Science session. Apr 19, 2016.
AAN Press release Zika Virus May Now Be Tied to Another Brain Disease. Apr 10, 2016.