Research sheds light on Zika virus' association with another brain disease

A new research reveals Zika virus' association with an autoimmune disorder that attacks the brain's myelin similar to multiple sclerosis.

Lead author Maria Lucia Brito Ferreira said though their 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.

Ferreira added more research will need to be done to explore whether there is a causal link between Zika and these brain problems.

For the study, researchers followed people who came to the hospital in Recife from December 2014 to June 2015 with symptoms compatible with arboviruses, the family of viruses that includes Zika, dengue and chikungunya.

All of the people came to the hospital with fever followed by a rash. Some also had severe itching, muscle and joint pain and red eyes. The neurologic symptoms started right away for some people and up to 15 days later for others.

Of the six people who had neurologic problems, two of the people developed acute disseminated encephalomyelitis (ADEM), an attack of swelling of the brain and spinal cord that attacks the myelin, which is the coating around nerve fibers.

In both cases, brain scans showed signs of damage to the brain's white matter. Unlike MS, acute disseminated encephalomyelitis 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-Barre syndrome (GBS), a syndrome that involves myelin of the peripheral nervous system and has a previously reported association with the Zika virus.

When they were discharged from the hospital, five of the six people still had problems with motor functioning. One person had vision problems and one had problems with memory and thinking skills.

Tests showed that the participants all had Zika virus. Tests for dengue and chikungunya were negative.

Ferreira said that 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. However, our study may shed light on possible lingering effects the virus may be associated with in the brain.

The study was presented at the 2016 American Academy of Neurology 68th Annual Meeting.