Idiopathic intracranial hypertension on the rise, study finds

A new study has found that a brain pressure disorder called idiopathic intracranial hypertension is on the rise, and the rise matches rising obesity rates. The study is published in the Jan.20, 2021 online issue of Neurology^®, the medical journal of the American Academy of Neurology. The study also found that for women, socio-economic factors such as income, education and housing may play a role in their risk.

Idiopathic intracranial hypertension occurs when the pressure in the fluid surrounding the brain increases. It can mimic the symptoms of a brain tumor, causing chronic and disabling headaches, vision problems and, in rare cases, vision loss. It is most often diagnosed in women of childbearing age. Treatment often involves losing weight. In some cases, surgery may be necessary.

The dramatic increase in idiopathic intracranial hypertension that we have found may be due to many factors, but most likely mainly to rising obesity rates. What is more surprising from our research is that women who live in poverty or other socio-economic disadvantage may also have an increased risk regardless of obesity. “

William Owen Pickrell, Ph.D., MRCP, study author, University of Swansea, Wales, UK and fellow of the American Academy of Neurology

For the study, the researchers used a National Health Care Database in Wales to analyze 35 million patient-years of data over a 15-year period, between 2003 and 2017. They identified 1,765 people with idiopathic intracranial hypertension during this period. Of the group, 85% were women. The researchers recorded the body mass index measurements of the study participants. The body mass index is calculated by dividing the weight by the height. For each person with the disorder, the researchers compared three people without it who were matched for gender, age, and socioeconomic status.

The socioeconomic status of each person with the disorder was determined based on their place of residence, using a national scoring system that takes into account factors such as income, employment, health, education and access to services. The study participants were then divided into five groups ranging from those with the least socio-economic benefits to those with the most.

Overall, the researchers found a six-fold increase in the number of cases of the disorder during the study. In 2003, per 100,000 people, 12 were living with the disease, compared to 76 people in 2017. Additionally, in 2013, per 100,000 people, two were diagnosed that year, up from eight in 2017.

The researchers found that the growing number of people living with the disorder matched the rising obesity rates in Wales during the study, with 29% of the population being obese in 2003 compared to 40% in 2017.

“The global prevalence of obesity almost tripled between 1975 and 2016, so while our research looked specifically at people in Wales, our findings may also have global relevance,” Pickrell said.

There were strong links for both men and women between body mass index and risk for the disorder. For women, there were 180 cases per 100,000 people during the study for those with a high body mass index compared to 13 women with a body mass index considered ideal. For men, there were 21 cases per 100,000 among those with a high body mass index compared to eight cases for those with an ideal body mass index.

The researchers also found that for women only, socioeconomic factors were related to risk. There were 452 women in the group with the least socioeconomic benefits, compared to 197 in the group with the most. Women in the least group had a 1.5 times higher risk of developing the disorder than women in the most group, even after adjusting for body mass index.

“Of the five socio-economic groups of the participants in our study, women in the two lowest groups made up more than half of the study participants,” Pickrell said. “More research is needed to determine which socio-economic factors such as diet, pollution, smoking or stress may play a role in increasing a woman’s risk of developing this disorder.

One limitation of the study was that the researchers identified the socio-economic status of participants by the regions in which they lived instead of obtaining individual socio-economic information for each participant.