The impact of monkeypox on the skin—such as disfiguring rashes—and flu-like symptoms has been described, but few researchers have investigated the neurological and psychological issues that the virus may cause. Historical reports indicate the occurrence of neurological complications in people infected with related variola virus and those vaccinated against smallpox. Therefore, James Bruntan Badnush, an academic doctor from Queen Mary University in London, and his colleagues wanted to determine whether monkeypox causes similar problems.
They reviewed all evidence prior to the current monkeypox pandemic regarding neurological or psychological issues in individuals infected with monkeypox. The results were published in the journal eClinicalMedicine. A small but notable percentage of individuals (2 to 3%) with monkeypox became extremely ill and experienced serious neurological problems, including seizures and encephalitis (inflammation of the brain that can cause long-term disability). They also found that confusion occurred in a similar number of those affected. It is important to note, however, that these figures are based on few studies with limited participants.
In addition to acute and rare brain problems, they observed evidence of a broader group of individuals with monkeypox experiencing more common neurological symptoms, including headaches, muscle pain, and fatigue. Through their examination of studies, the severity and duration of these symptoms remained unclear. It is also unclear how many monkeypox patients suffer from psychological issues—such as anxiety and depression—since few studies have explored this. Among those that did, poor mood was reported frequently.
Researchers do not know what factors contribute to the occurrence of these neurological and psychological problems in individuals with monkeypox. They want to understand whether the monkeypox virus strain and the severity of infection influence these issues. However, they could not investigate this properly as it has not been consistently reported in studies.
Although individuals infected with monkeypox can exhibit neurological and psychological symptoms, the studies in the research paper cannot definitively claim that the virus is the cause of these problems. Future research exploring this matter will need to follow individuals without preexisting neurological conditions before they contract monkeypox. If the virus is responsible for these issues, the underlying biological processes are unclear, and could include direct entry of the virus into the nervous system, immune response, or something entirely different.
The stigma faced by individuals with monkeypox and the impact of the disfiguring rash may also contribute to psychological distress, such as poor mood. The research focused on evidence prior to the current monkeypox pandemic. Most data came from West Africa and from hospitalized individuals with infections, while the current outbreak has mostly affected North America and Western Europe. It remains unclear to what extent symptoms from previous outbreaks reflect what is being observed now.
A study in the New England Journal of Medicine included over 500 individuals with monkeypox from 16 countries. Although no cases of encephalitis or seizures were reported, headaches and fatigue were found in more than a quarter of those infected, and low mood was noted in up to one in ten individuals. However, two confirmed cases of encephalitis due to monkeypox were recently reported in Spain. More monitoring is needed to determine the true extent of more severe issues, such as encephalitis and seizures.
The monkeypox outbreak remains a global concern, and continuous public health measures—including improved access to vaccination—are needed. While monkeypox primarily causes flu-like symptoms and skin problems, recent studies—including subsequent research—indicate that neurological and psychological symptoms are common. A wave of severe brain problems is not expected, but complications such as encephalitis and seizures may occur in a small percentage of people. Further research is needed to ascertain whether these symptoms persist over time and whether they are caused by monkeypox.
