Health: Obesity crisis may be putting more people at risk of a once-rare brain disorder

Obesity crisis may be putting more people at risk of a once-rare brain disorder that can cause headaches and blindness

  • Idiopathic intracranial hypertension presents with symptoms like a brain tumour
  • It is caused by an increase in the pressure of the fluid that surrounds the brain
  • Researchers from Swansea studied incidences of the condition from 2003–2017
  • They found that the total number of cases in Wales tripled during that period
  • The team noted that — among women — poverty is linked to an increased risk 

The obesity crisis may be increasing the number of incidences of a once-rare brain disorder that can cause chronic headaches and blindness, a study has warned.

Researchers from Wales found analysed 1,765 cases of idiopathic intracranial hypertension (IIH) — a condition which mimics the symptoms of a tumour.

It occurs when the pressure in the fluid surrounding the brain rises — and can cause chronic, disabling headaches and varying degrees of vision problems.

A common treatment for the condition involves a program of weight loss. Women of child-bearing age are considered to be at the highest risk from the condition.

The team said that IIH diagnoses rose six-fold between 2003–2017, with the number living with the disorder increasing from 12 people out of every 100,000 up to 76.

In 2013, similarly, 2 people out of every 100,000 were identified with the disorder — while the rate had increased to eight people diagnosed each teat by 2017.

The obesity crisis may be increasing the number of incidences of a once-rare brain disorder that can cause chronic headaches and blindness, a study has warned (stock image)

Looking at 35 million patients in Wales over a 15 year period, the new study identified 1,765 cases of idiopathic intracranial hypertension — with 85 per cent of these patients being women, the researchers said.

The team found strong links — for both men and women — between higher body mass indices, or ‘BMI’, and risk of the developing the disorder.

Among the women identified by the study were 180 cases where the individual in question had a high body mass index, as compared to just 13 cases where the women had an ‘ideal’ BMI.

For the men, meanwhile, there were 21 cases among those with a high body mass index, as compared to eight cases for those with an ideal BMI.

The team also found that — for the women only — socioeconomic factors appeared to play a role in determining their risk.

The women in the group with the fewest socioeconomic advantages had 1.5 times the risk of developing the disorder than women in the group with the most advantages — even after the researchers adjusted for body mass index.

‘The considerable increase in idiopathic intracranial hypertension we found may be due to many factors but likely mostly due to rising obesity rates,’ said paper author and consultant neurologist Owen Pickrell of Swansea University.

‘What is more surprising from our research is that women who experience poverty or other socioeconomic disadvantages may also have an increased risk independent of obesity,’ he continued.

‘Of the five socioeconomic groups of our study participants, women in the lowest two groups made up more than half of the female participants in the study.’

‘More research is needed to determine which socioeconomic factors such as diet, pollution, smoking or stress may play a role in increasing a woman’s risk of developing this disorder.’

The full findings of the study were published in the journal Neurology. 

WHAT IS INTRACRANIAL HYPERTENSION?

Intracranial hypertension (IH) is the medical term for a build-up of pressure in the brain.

This can come on suddenly due to a severe head injury or stroke, which is known as acute IH.

Chronic IH is rare. It does not always have a cause but can be triggered by a blood clot on the brain, or a brain tumour or infection.

Symptoms can include:

  • Throbbing headache that may be worse in the morning or when coughing but relieved when standing
  • Blurred or double vision
  • Temporary loss of vision, such as ‘greying out’ for a few seconds
  • Nausea and vomiting
  • Drowsiness and irritability

Cases with no obvious cause are called idiopathic IH. This is more common in women in their twenties and thirties.

Idiopathic IH has been linked to obesity, chronic kidney disease and lupus.

It may also be triggered by hormone problems, an abnormal number of red blood cells and certain drugs, like steroids.

This form of the condition is thought to affect two in every 100,000 people in the UK, statistics show. Its US prevalence, and that of chronic IH, is unclear.

Treatment usually involves medication to remove excess fluid from the brain. Shunt surgery may also be required to divert this fluid elsewhere. 

Left untreated, chronic IH can be life-threatening. Idiopathic IH also causes vision loss in one in every five to 20 people if untreated.

Source: NHS