Oren Klein, 37, finance professional from South Florida, USA, first encountered cluster headaches as a child. “I would get painful episodes after a rigorous activity, notably in cold weather,” he recollects.
Unable to comprehend this pain as a young boy, he would merely put his head down and sleep through the pain whenever headaches struck.
Cluster headaches are short-duration, one-sided headaches with the pain around one eye. The attacks last for a few weeks and up to a few months, followed by periods of relief.
Dr Mark Burish, Director at the Will Erwin Headache Research Center, UTHealth Houston Neurosciences, USA, says cluster headaches are much shorter than migraines, and each headache episode lasts from 15 minutes to three hours. “These short bursts of intense pain can happen up to eight times a day,” he adds.
Read more: The headache spectrum: types of headaches
Not triggered by sinus
Dr Andrea Carmine Belin, a principal researcher at the Department of Neuroscience, Karolinska Institute, Sweden, says cluster headaches have accompanying symptoms. Tears, runny nose and redness of the eye occur around the affected eye region where the pain is concentrated. Men are prone to them.
Associated symptoms make the diagnosis harder, as they are also seen in sinus headaches. A misdiagnosis can lead to ineffective treatment, as happened in Klein’s case. As a teenager, he was treated for sinus and allergies. “It would help with the pain, but too much of the treatment] would cause insomnia,” he recalls.
There is another reason for misdiagnosis. Dr Burish explains, “Cluster headaches often occur during the spring and autumn seasons when most sinus and allergy headaches happen.”
Predictable punctuality
Cluster headaches occur regularly, at the same time every day, usually at night and mostly during spring and autumn seasons. Due to its predictability, scientists at first suspected that the hypothalamus was involved in these headaches. The hypothalamus is the timekeeper in the brain.
“The posterior hypothalamus is involved, and it plays a role in the circadian and circannual pattern of attacks,” explains Dr Belin. In support, several imaging studies have found that the hypothalamus appears more active during a cluster headache attack.
Read more: Why some headaches recur with CLOCKwork precision
Unbearable headaches
According to Klein, cluster headaches visit him for about eight weeks, twice a year, residing in and around his right eye. He describes his pain as a brain freeze with excruciating pressure behind his eye that does not stop after five seconds. “[The pain] stays until you want to pull your eyes out, make you feel faint, and this lasts an hour. The only hope is you know it will end. But then you know it will be back,” he says.
The main culprits behind the excruciating pain are the trigeminal nerve, the blood vessels that surround this nerve, and its interaction with the autonomic nervous system. “This pathway is primary in the severe pain processing and concentration towards one side,” she says.
Dr Burish adds that the debilitating pain can physically and mentally drain people having demanding jobs, “For some, these pains happen up to eight times a day. So, you can imagine if you have a headache that lasts even 15 minutes, but it is happening eight times a day. It is that intense.”
In a recent study, Dr Burish assessed the pain patterns in people, asking them to rate the pain intensity of their various health conditions on an ascending scale of one to 10. People with cluster headaches rated their pain at 9.7, much worse than a migraine at 5.4, labour pain at 7.2 and kidney stones at 6.9.
This shows how incredibly painful cluster headaches can be. It is no wonder that cluster headaches are sometimes called suicide headaches. “It is excruciating and should be considered a real disability,” Klein adds.
What causes these headaches is still unclear. “Between 2 and 20 per cent of the people with cluster headaches report that they have close relatives [who also have] the disorder,” says Dr Belin, indicating that genetics could be at play here. Some studies have identified alcohol consumption as a potential trigger.
Not enough treatments
Due to the prevalent research gaps, treatments, too, fall short. “In the last 10 years, we have come a long way in understanding cluster headache, but more research needs to be done,” says Dr Belin.
However, Dr Burish and Dr Belin say that oxygen inhalation and corticosteroid treatments can give immediate relief. For Klein, oxygen therapy was a lifesaver. “It was the first sign of real hope for this in my life,” he says.
Solace in numbers
While cluster headaches are unbearable and without a cure, many have found solace in online communities. Here, they discuss and share their experiences and symptoms openly. “I finally felt I wasn’t alone,” says Klein.
Life seems better to him in his 30s than in his 20s as he believes he has at least some answers now. “It is not always good days, but I am figuring out how to live with it, and I try to live my best life with my three wonderful children,” he says.
