Diabetes jab to beat chronic blinding headaches

Thousands of Britons blighted by ‘blinding’ headaches could see attacks reduced by a third thanks to a drug used to treat diabetes.

At least 2,000 people in the UK suffer idiopathic intracranial hypertension. The main symptom of the condition, in which excess fluid builds around the brain, is a persistent, debilitating headache.

But in some cases, the increased pressure in the skull can also damage the nerve that connects the eyes and the brain, causing blindness.

Global cases of the condition have risen by 350 per cent over the past decade, thought to be because the problem can be triggered by obesity. There are no licensed treatments, so doctors rely on drugs that are used to treat similar illnesses.

Now researchers at the University of Birmingham have found that regular injections of exenatide, a drug used to help diabetics lose weight, is both safe and effective.

Now researchers at the University of Birmingham have found that regular injections of exenatide, a drug used to help diabetics lose weight, is both safe and effective

‘This is the first medicine seen to have a strong effect,’ says Professor Alexandra Sinclair, consultant neurologist at University Hospitals Birmingham NHS Foundation Trust and lead investigator on the trial. ‘It works directly on the part of the brain that produces fluid, slowing its release and, as a result, reducing pressure.’

Idiopathic intracranial hypertension develops due to an excess of cerebrospinal fluid – the protective, liquid cushioning that surrounds the brain and spinal cord. Over time this puts pressure on the delicate blood vessels that line the brain as well as the optic nerves which transfer visual information. The pressure leads to severe headaches – which can be constant – as well as loss of vision. Patients can also suffer nausea and tinnitus – constant ringing in the ears.

Experts are not certain what causes idiopathic intracranial hypertension, but it is believed to be a fault with the balance of hormones that control the release of brain fluid. Studies show people with a higher body mass are at greater risk.

‘The same hormonal problems that cause some people to be a higher weight could also be behind the condition,’ says Prof Sinclair.

A lumbar puncture is used for diagnosis. This is a procedure where a sample of cerebrospinal fluid is taken via a needle in the lower back and the pressure measured. Doctors also rule out other illnesses which have similar symptoms, such as brain tumours.

As there are few treatments available, specialists often give diuretics, or water pills, such as the glaucoma drug acetazolamide, to help expel excess fluid – but half of patients suffer side effects.

In extreme cases, doctors may perform an operation to drain excess fluid from the brain. This is a last resort, as risks include infection and bleeding on the brain.

But now, the University of Birmingham team have conducted a 12-week clinical trial in which seven patients were given a twice-daily jab of exenatide. At the start, participants suffered headaches on 22 days per month on average. During the trial, the drug reduced the pressure in the brain. The frequency of participants’ headaches was also slashed by 36 per cent – to 14 days. ‘We also saw an improvement in sight,’ says Prof Sinclair.

The team is now running a follow-up trial with 240 patients across the globe and have reformulated the drug into a weekly injection.

Liz Formby ‘begged’ Prof Sinclair to let her stay on the drug when the trial came to an end. ‘My headaches had subsided and the deterioration of my sight paused,’ she said.

Liz, 63, was diagnosed with idiopathic intracranial hypertension in her late 30s after a lapse in vision almost caused a car crash.

‘I had been suffering headaches that felt as if my head was being pulled off,’ she said.

An optician referred Liz to neurologists at her local hospital, where she underwent tests and was diagnosed with the condition. Doctors prescribed painkillers and advised Liz to lose weight.

In 2018 she took part in a clinical trial of exenatide, injecting herself twice daily for three months.

‘For the first two weeks it made me feel rotten,’ said Liz, ‘but then the headaches subsided. Instead of four a week, it was one and far less intense. My sight didn’t improve but it stopped getting worse.’

When the trial ended, Liz said: ‘The sharp pain came back.’

She added: ‘People asked why I was taking an experimental drug and putting myself at risk. To me, it was a no-brainer – I want to help doctors help people like me. And, clearly, this drug is helping.’