The Kenyan authorities said that dozens of girls in Kenya who were exposed to a “disease” that caused paralysis were actually victims of hysteria.
More than 100 female students suddenly fell ill with the mysterious disease over the past week, requiring them to be taken to the hospital.
The incident occurred at St. Teresa Irigi Girls' Secondary School in the town of Musoli, 374 kilometers (232 miles) northwest of Nairobi, the capital of Kenya.
The disturbing footage circulated online appeared to show the female students struggling to walk and shaking uncontrollably.
The girls were also seen tied to bed and convulsing in what appeared to be a hospital in clips that claim to show the extent of the crisis.
But local officials have now said the spate of mysterious cases was actually caused by hysteria. They blamed students' anxiety about exams.
Health officials in Kenya immediately launched an investigation into the cause of the outbreak, fearing it could have "catastrophic" consequences if it became contagious.
Samples of blood, stool and urine from the infected girls were sent to laboratories.
Local news website Nation Africa, citing Dr. Bernard Wesonga, reported that samples were collected from female students who were admitted to four hospitals within the province and were transferred to government laboratories where laboratory and sensitive tests were conducted.
The Kakamega District Health Executive added: “The results showed that the students were not suffering from any illness. This indicates a psychological challenge that could have been driven by panic.”
Boniface Kibaki, Minister of Education of the Catholic Diocese of Kakamega, speaking to local media outlet ACI Africa, indicated that the female students were examined in hospitals and found to be free of infection.
Adding: "The medical results came back with negative results. There is no disease. It is more of a psychological issue."
Doctors, anthropologists and sociologists who have studied mass hysteria, known medically as mass psychopathology (MPI), have failed to come up with any clear explanation for this phenomenon.
Previous cases of mass psychopathology reveal that women are more vulnerable than men. The condition often begins with one individual.
According to Robert Bartholomew, an American sociologist who specializes in mass hysteria and social panic, there are two main types of mass psychopathology.
He stated in a research paper published in 2013 that the first type is anxiety hysteria resulting from severe and sudden stress within a cohesive group.
Often, this is the result of an unfamiliar unpleasant odor that is believed to be harmful. Symptoms usually include dizziness, headache, fainting, and breathing changes, but most patients recover within 24 hours.
The second type is motor hysteria, which is caused by long-term anxiety with common signs that include tingling, trembling, difficulty walking, uncontrollable laughter and crying, communication difficulties, and trance-like states.
New clue discovered as to why Parkinson's disease spreads in the brain like an infection
A first-of-its-kind study has revealed that damaged mitochondrial DNA (a cellular organelle) triggers a chain reaction that can spread Parkinson's disease to other parts of the brain in a manner similar to an infection.
Mitochondria, small organelles in our cells that produce energy, contain their own DNA bank, separate from the chromosomes in the cell nucleus.
Damaged mtDNA can activate two proteins involved in the immune system, and researchers have found that these specific proteins are upregulated in the brains of both humans with Parkinson's disease and mice designed to model the condition.
The researchers also identified another protein, which plays a key role in spreading damaged mitochondrial DNA to other neurons, which may be a new target for developing treatments to prevent the development of Parkinson's disease.
A team from Denmark and Germany believe blood tests could detect damaged mitochondrial DNA, as early biomarkers of Parkinson's disease.
Biotechnologist Shohri Isazadeh Navikas from the University of Copenhagen in Denmark says:
"For the first time, we can show that mitochondria, the vital energy producers inside brain cells, especially neurons, are damaged, leading to disruptions in mitochondrial DNA. This spreads disease like wildfire through the brain."
In the past, researchers focused on studying genetic factors to explain cases of Parkinson's disease among family members. Over time, it became clear that these factors could not explain the majority of patients' conditions.
"Our findings demonstrate that the spread of damaged genetic material, mitochondrial DNA, causes symptoms reminiscent of Parkinson's disease and its progression to dementia," explains Isazadeh Navikas.
The researchers studied post-mortem brain samples from people with and without Parkinson's disease symptoms in order to identify molecular pathways linked to the pathology.
They found that two proteins, TLR9 and TLR4, are activated in the proliferation of damaged mtDNA, and these proteins are upregulated in Parkinson's patients.
The researchers then used a mouse model of Parkinson's disease with mutations in the genes that control these pathways to study the role of mitochondrial DNA damage.
TLR9 and TLR4 signaling in these mice was activated in specific molecular pathways found in humans, as was damaged mitochondrial DNA expelled from neurons. This can then spread to other neurons and cause neurotoxicity.
The dementia-like behavioral symptoms of Parkinson's disease, such as neuropsychiatric, motor and cognitive impairments, were also induced in healthy mice when they injected damaged mitochondrial DNA into their brains.
“Small bits of mitochondria are released into the cell,” says Isazadeh Navikas. “When these bits of damaged DNA are misplaced, they become toxic to the cell, prompting neurons to expel this toxic mitochondrial DNA.”
Damage to nerve cells in healthy mice occurred in areas far from the injection site as well. Damaged mtDNA appears to spread the features of dementia resulting from Parkinson's disease in a similar way to how viruses spread.
With further analysis, the researchers discovered that a protein known as Rps3 helps TLR4 recognize damaged mtDNA and helps expel toxic parts from nerve cells.
“Due to the interconnected nature of brain cells, these toxic DNA fragments spread to nearby and distant cells, similar to an out-of-control wildfire ignited by an ordinary fire,” Isazadeh-Navikas explains. “It is possible that damage to mitochondrial DNA in brain cells leaks from the brain into the blood.” ".
“These insights may pave the way for innovative therapeutic strategies and monitoring approaches for Parkinson's disease,” the researchers wrote.
The study was published in Molecular Psychiatry.