VANCOUVER -- Nearly all Liberian Ebola survivors examined in a study conducted by National Institutes of Health researchers reported neurological symptoms, persisting in many cases for more than a year.
About three-quarters of the 164 survivors studied as of February 2016 said they experienced headaches during or after stays in Ebola treatment units, and half reported difficulty walking and overall muscle weakness, according to Lauren Bowen, MD, a National Institute of Neurological Disorders and Stroke clinical fellow.
Moreover, headache, depression, and memory loss continued in half or more when interviewed a year or more after treatment unit discharge, Bowen told attendees here at the .
She said one of the most surprising findings was the frequency of hallucinations -- some of which were very concerning. Bowen mentioned 10-year-olds having hallucinations severe enough to require psychiatric hospitalization.
Almost one-quarter of the sample reported having hallucinations during or after their treatment unit stays. These tended not to be persistent, with only 4% reporting such symptoms at follow-up. But Bowen noted that this is still far above the level expected in the general Liberian population.
Frequencies of the most common persistent neurospychiatric symptoms were as follows:
- Headache: 65%
- Memory loss: 55%
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Depression: 49%
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Trouble concentrating: 43%
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Muscle soreness: 36%
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Lack of motivation: 34%
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Personality changes: 32%
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Abnormal sensation: 29%
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Sexual dysfunction: 29%
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Insomnia: 26%
Bowen said most of the sexual problems were of the under-functioning type, but hypersexuality was reported by some participants.
Less common symptoms included tremor, abnormal thoughts and behaviors, and incontinence.
Objective neurological exams at follow-up confirmed that abnormalities were common. Among the most frequent were abnormal cranial nerve pursuits (41%) and saccades (25%) as well as peripheral neuropathy (27%) and abnormal reflexes (32%).
Problems with gait and coordination and frontal release signs were seen in 10% or more of participants.
Patients were rated for disability on the modified Rankin scale. None had scores of 4 or 5 (moderate or severe disability) and 85% were rated at 1 (symptoms but no significant disability). Bowen noted, though, that the study methodology could have biased the sample toward lower disability.
She pointed out that, to receive the follow-up exams, participants had to go from their homes around Liberia to the research facility in the capital of Monrovia. She said it was "easy to imagine" that severely disabled individuals would be effectively excluded from the follow-up.
Reasons for the persistent symptoms remain unclear, according to the investigators, although continued presence of Ebola virus does not seem to be involved.
A co-investigator on the study, Bridgette Billioux, MD, also of NINDS, said lumbar punctures were being performed on consenting participants and, thus far, no evidence of Ebola virus in cerebrospinal fluid has been found. Nor have any other clear abnormalities in CSF components been identified.
Bowen said the group's goal was to complete evaluations on 200 survivors.
For comment on an interim analysis of the study data, see this 51˶ video.
Disclosures
The study was conducted by the National Institute of Neurological Disorders and Stroke. All authors were NINDS employees and had no conflicts of interest to declare.
Primary Source
American Academy of Neurology
Bowen L, et al "Survivors of ebola virus disease have persistent neurological deficits" AAN 2016; Abstract S53.003.