Under Pressure

Follow the Facts

Like Stefanie, I had never heard of Emperor Taisho before we started researching for this series. After weeks of reading, I know little more than when I started. Any cursory Google search will tell you that Taisho suffered from mental illness, becoming “deranged” in his later years, but no one can tell you how. We know that his son became regent in his place in 1921, which is the most enduring piece of evidence that Taisho was unfit to rule. But 20th century Japan was not the most transparent of environments, and we just don’t have all the information about what exactly prevented Taisho from carrying out his duties as Emperor. 

For all the vague and sparse details available about Taisho, there is one thing all sources absolutely agree on: he became sick with cerebral meningitis shortly after birth and was never the same. Meningitis has therefore been presumed to be the root of Taisho’s later psychiatric problems. Normally, I describe the symptoms of our subjects and work backwards to determine what the biological roots might be. This week, I’m turning things around. Given the limited information we have on Taisho and his struggles with mental illness, I’m going to start with what we know, that he had meningitis, and from there, describe what symptoms he may have struggled with as a result.

It Doesn’t (Dura) Mater

A fact that jumped out at me from Stefanie’s research was that 11 of Taisho’s 15 siblings died young. It sounded like a staggering number of deaths, but I did my homework to make sure it was unusual for the time. Indeed, Emperor Meiji’s children experienced a mortality rate double that of the rest of Japan in 1865, which was 36 deaths per 100 children under the age of 5. Unfortunately, we can’t know for sure why so many of Meiji’s children failed to survive childhood. Many scholars have pointed out that the restricted pool of eligible mates for the Japanese imperial family may have led to inbreeding, resulting in nonviable offspring.  

The childhood mortality rate in late 1800s Japan was high at 360 deaths per 1,000 children under age 5, but this was still half the mortality rate of the Emperor’s family. Statistica

Taisho narrowly avoided becoming another premature death when he contracted meningitis as a newborn. Meningitis refers to swelling of the meninges, which are layers of protective membrane that surroud the delicate brain and spinal cord. The outermost layer is the dura mater, a thick membrane that encases sinuses important for draining fluid from the brain. Next is the arachnoid mater, which separates the dura layer from the cerebrospinal fluid, the fluid surrounding the brain and spinal cord. Last is the pia layer, a delicate membrane that clings tightly to the surface of the brain and spinal cord like saran wrap. The pia mater provides blood supply to the nervous system. Inflammation in these layers puts pressure on the underlying brain and spinal cord, disrupting the normal function of the nervous system.

The skull isn’t the only layer separating your brain from your scalp. The dura, arachnoid, and pia layers support the function of the nervous system and protect it from injury. Mayo Clinic

Brain on Fire

Meningitis can have a variety of causes. Most commonly, a viral or bacterial infection causes an immune response in these membranes, causing them to swell. However things like brain trauma or cancer can also trigger meningitis. Given that the meninges are so important for the protection and function of the nervous system, it will come as no surprise that inflammation of the dura, arachnoid, or pia mater can have devastating effects. The symptoms and prognosis can vary based on the cause of disease (viral, bacterial, fungal, aseptic, etc.) and primary location (brain versus spinal cord), but the hallmarks are flu-like symptoms followed by fever, headache, nausea, impaired vision, dizziness, and stiff neck. In infants like Taisho, the symptoms are different. Early signs of meningitis in babies include seizures, irregular breathing, vomiting and reduced feeding. These are likely the warning signs that alarmed Taisho’s family shortly after his birth.

Meningitis symptoms in infants are distinct from those seen in adults. Medical News Today

Meningitis can also lead to long-term issues. According to the United Kingdom’s National Health Service, between 33 and 50 percent of people who have had bacterial meningitis will go on to have lasting symptoms. These might include loss of hearing or vision, impaired coordination, and cognitive changes such as decreased memory or attention span.

Long-Term Relationship

Long-term consequences of meningitis are of particular concern when the patient’s brain is still developing, like Taisho’s was when he became ill. The details are a little fuzzy on the time of disease onset, but it’s likely that Taisho had neonatal meningitis, meaning he contracted it within the first 28 days of life. It’s been hard to rigorously study the developmental impacts of neonatal meningitis because of the few number of cases, but a 2003 paper was able to look at 111 children from the UK who survived neonatal bacterial meningitis (note: we don’t know that bacteria caused Taisho’s meningitis, but most neonatal meningitis research is done with bacterial cases because the root cause is easier to verify). All of the children were evaluated when they were 9 or 10 years old, eliminating confounding variables that could emerge from participants being at different stages of development. The researchers performed systematic evaluations of the children’s sensory, motor, and cognitive abilities. Compared to children born in the same hospital at the same time, kids who had meningitis as newborns had a lower average IQ, worse performance on a motor assessment , and increased likelihood of seizures, hearing loss, or a build up of cerebrospinal fluid. Keep in mind that these are the outcomes for children who had the benefit of modern medicine, not the resources available to Taisho in Japan in the late 19th century!

This table shows the results of the 2003 study. IQ scores, motor battery assessment scores, and percentage of children with meningitis (cases) or children born in the same (hospital controls) or different hospital (GP controls). Overall, neonatal meningitis led to lower IQ, worse motor skills, and increased likelihood of seizures. Stevens et al 2003

A 2011 review by researchers out of Johns Hopkins (not biased, swear!) sought to synthesize all available studies of neonatal bacterial meningitis patients that followed up with participants 5 years or more after infection. The results mirrored that of the 2003 study, finding that 78.3 percent of the children analyzed had intellectual or behavioral problems when evaluated 5-20 years after disease. This is consistent with what Stefanie told us about Taisho last week: that he had trouble in school due to poor attention and misbehavior. 

Risky Business

I think it’s intuitive why meningitis perinatally can be so damaging, but what makes some neonates susceptible to meningeal inflammation? Infections of any kind are more dangerous for newborns because their immune system is still developing. Antibodies, those things you’ve been hearing about non-stop for the past year, are key players in immunity against a variety of pathogens. But babies don’t start cranking out their own antibodies until several months after birth. In the meantime, they rely on antibodies from their mother that they received in utero or through breast milk. As good as mom’s supply is, infants are more likely to have a more limited antibody repertoire that leaves them susceptible to infections. 

From this graph, you can see that the levels various antibodies (IgA, IgD, IgE, IgG, IgM) that make up our humoral immunity don’t reach those of adults until over a year after birth, leaving babies more susceptible to infections. Braibant and Barin, 2013

There is research suggesting that there are additional factors that predispose infants to meningitis. One study found that neonates with meningitis were more likely to be born prematurely and at a low weight. In addition, maternal vaginal infections and oxygen shortage during birth were also linked to neonatal meningitis. This also made me think of Taisho. Stefanie mentioned last week that Taisho’s birth was extremely difficult, so much so that his mom was never welcomed in Meiji’s bed again. Those are all of the details we have, but it made me wonder if Taisho lacked oxygen during the long and arduous process, or if the trauma of the delivery triggered inflammation in his meninges. 

Man of Mystery

The little information we have about Taisho’s childhood, that he was a bad student with poor health, aligns with modern observations of children who survived neonatal meningitis. We are largely lacking studies that track outcomes for these infants once they’ve reached adulthood, but it’s likely that the sensory, motor, cognitive, and behavioral effects of neonatal meningitis persist. The nervous system is delicate, particularly in early life. Meningitis not only puts physical pressure on the brain and spinal cord, but also damages the tissues that they rely on for support and protection. This causes major disruptions to the developmental processes that normally occur in newborns, altering the trajectory of nervous system organization and functioning for life. Neonatal meningitis creates deficits that would disrupt any life, so it is easy to imagine that Taisho was ill-equipped to deal with the demands that came with his position as emperor. But did meningitis leave Taisho truly “deranged” as he has so often been vaguely described? Stefanie will investigate next week to get to the bottom of why he was unfit for the throne: did the reason lay in his brain or in his subject’s heads?


References

Chandran, A., Herbert, H., Misurski, D., & Santosham, M. (2011). Long-term Sequelae of Childhood Bacterial Meningitis. Pediatric Infectious Disease Journal,30(1), 3-6. doi:10.1097/inf.0b013e3181ef25f7

Khaleesi, N., & Afsharkhas, L. (2014). Neonatal Meningitis: Risk Factors, Causes, and Neurologic Complications. Iranian Journal of Child Neurology,8(4), 46-50.

Meningitis and Encephalitis Fact Sheet. (n.d.). Retrieved from https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Meningitis-and-Encephalitis-Fact-Sheet

Meningitis Complications. (n.d.). Retrieved from https://www.nhs.uk/conditions/meningitis/complications/

O’Neill, A. (2019, October 16). Japan: Child mortality rate 1865-2020. Retrieved from https://www.statista.com/statistics/1041855/japan-all-time-child-mortality-rate/

Stevens, J. P., Eames, M., Kent, A., Holket, S., Holt, D., & Harvey, D. (2003). Long term outcome of neonatal meningitis. Archives of Disease in Childhood – Fetal and Neonatal Edition,88(3), F179-F184. doi:10.1136/fn.88.3.f179

The Meninges. (n.d.). Retrieved from https://teachmeanatomy.info/neuroanatomy/structures/meninges/

2 thoughts on “Under Pressure

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: