Persistent Neurologic Symptoms Common in Ebola Survivors

Megan Brooks

March 16, 2016

Survivors of Ebola infection may experience neurologic symptoms months after the initial infection clears, researchers are finding.

"Many patients that we've seen have had some signs of neurologic dysfunction both by what they describe and also on clinical exam," Bridgette Jeanne Billioux, MD, clinical fellow, National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, Maryland, noted in an interview with Medscape Medical News.

"Many describe headaches and memory loss, sometimes very mild, but also sometimes more prominent, that prevent them from going back to their jobs. A few people had seizures and also some vision issues," she said.

"And on clinical exam, when we looked at these patients, a lot of times we would find abnormalities; sometimes they were extremely subtle so that if another physician were looking at this patient they might not pick up on it, but because we were doing very careful neurologic exams by board-certified neurologists we did find subtle findings and also more obvious findings as well," Dr Billioux said.

For example, "there were subtle eye movement abnormalities that maybe only a neurologist or ophthalmologist would pay attention to and then sometimes there were pretty obvious eye movement abnormalities."

Ebola Specific?

Dr Billioux and a team of neurologists from NINDS examined 82 Ebola survivors from Liberia with an average age of 35 years. Their preliminary findings were released February 24 and will be presented at the upcoming American Academy of Neurology (AAN) 2016 Annual Meeting in April.

At least 6 months after the onset of Ebola virus disease, most of the survivors have some neurologic abnormality, the researchers found.

The most common ongoing problems were weakness, headache, memory loss, depressed mood, and muscle pain. Two people were suicidal and one had hallucinations. Common neurologic findings on examination include abnormal eye movements, tremors, and abnormal reflexes.

"These people did not have these problems before they had Ebola infection. They developed these problems during infection, and we were struck by the fact that so many of these problems were still present after the infection," Dr Billioux said.

The study is part of the NINDS larger Prevail III study, which is expected to enroll 7500 people throughout Liberia, including 1500 Ebola survivors and up to 6000 of their close contacts (serving as controls) and follow them for up to 5 years.

Including control patients from West Africa is important, Dr Billioux said, "because there are lots of health issues in West Africa that could lead to neurologic issues so we hopefully can tease out what is due to Ebola and what is not."

Dr. Billioux also said it's unclear at present how Ebola affects the brain. "We know that Ebola causes a massive cytokine storm and that can affect the brain, leading to permeability in the blood-brain barrier and inflammation in the brain. We also know that in the acute phase some patients even have a meningitis or meningoencephalitis type of presentation, which can also affect the brain," she explained.

She noted that most of the Ebola-infected patients in West Africa have not had any neuroimaging studies performed. "It is challenging to get an MRI in West Africa," Dr Billioux commented. Among the Ebola survivors who have had neuroimaging performed in developed countries, some showed "pretty remarkable signs, like very small brain bleeds and some not so small bleeds," she said.

"We are learning more and more of lingering symptoms that can plague survivors long after they recover from Ebola, and neurologic illness is definitely on the list," Amesh Adalja, MD, spokesperson for the Infectious Diseases Society of America, noted in an interview with Medscape Medical News.

And that doesn't surprise him. "It makes sense because Ebola is a critical illness and we know that when people have critical illnesses that put them in the intensive care unit, they often have lingering symptoms similar to what is described in this study with headache, memory loss, depressed mood, and those types of things," said Dr Adalja, from University of Pittsburgh Medical Center for Health Security in Pennsylvania.

"We know that Ebola can get into the central nervous system," he noted. Going forward, it will be important to "figure out what the risk factors are for these types of persistent symptoms; whether or not certain viral loads or clinical presentations are more or less likely to lead to these long-term consequences. Are people who are treated very rapidly or who don't have a severe bout of Ebola less likely to have these lingering symptoms, or is everybody equally at risk? These are important questions that need to be addressed," Dr Adalja said.

The study was supported by NINDS, the National Institute of Allergy and Infectious Diseases, and the Liberian Ministry of Health.

American Academy of Neurology (AAN) 2016 Annual Meeting. Abstract 3295.


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