Scientists recently linked a new brain disorder in adults to the Zika virus: acute disseminated encephalomyelitis, a serious autoimmune disease that leads to swelling of the brain and spinal cord.
The Zika virus has already been linked to Guillain-Barré syndrome, a condition in which the immune system attacks the nerves and can cause temporary paralysis and difficulty breathing.
Researchers said the latest findings, which show that Zika can cause harm to the central nervous system, add to the virus's ever increasing list of associated neurological damage.
"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 Dr. Maria Lucia Brito Ferreira, a neurologist at Restoration Hospital in Recife, Brazil, who led the study. "Much more research will need to be done to explore whether there is a causal link between Zika and these brain problems."
The latest study involved six patients who came to the Brazilian hospital between December 2014 and June 2015 with symptoms compatible with arboviruses, which include Zika, dengue and chikungunya.
Researchers noted that there were a total of 151 cases of neurological manifestations at the hospital in that time period. All the patients with neurological manifestations had come to the hospital with a fever followed by rash. Many of the patients also suffered severe itching, red eyes and muscle and joint pain.
The study revealed that two of the six patients in the study developed acute disseminated encephalomyelitis, which researchers described as sudden episodes of brain and spinal cord swelling that damages the myelin or coating around the brain's nerve fibers. Brain scans revealed that the two patients also had damage to their brain's white matter.
Study results revealed that four of the patients in the study developed Guillain-Barré syndrome, a syndrome that has previously been linked to the Zika virus. Five of the six patients had motor functioning problems, one person reported vision problems and another reported memory and cognition problems.
Researchers noted that tests confirmed that all six patients had the Zika virus, while tests for dengue and chikungunya all came back negative.
"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."
The findings will be presented at the American Academy of Neurology's 68th Annual Meeting in Vancouver, Canada, April 15 to 21.
