Cluster headache (CH) is associated with a significantly increased risk for comorbid conditions, including mental disorders and other neurologic disease, leading to significant disability and absenteeism, new research shows.
Results from a Swedish register-based study also showed that patients with CH had a sixfold increased risk for central nervous system (CNS) disorders and a twofold increased risk for musculoskeletal disorders.
Although CHs are often more prevalent in men, researchers found that multimorbidity rates were significantly higher in women.
In addition, rates of external injuries were significantly higher among individuals with CH than among persons without CH.
“The findings very clearly indicate that cluster headache patients suffer from other health issues as well and that they are at risk of having longer periods of times when they cannot work,” lead investigator Caroline Ran, PhD, a research specialist in the Department of Neuroscience at the Karolinska Institutet, Stockholm, Sweden, told Medscape Medical News.
“It’s really important for clinicians to look at cluster headaches from a broader perspective and make sure that patients are followed up so that they don’t risk ending up in a situation where they have several comorbidities,” Ran added.
The findings were published online December 14 in Neurology.
CH is one of the most severe and debilitating types of headache. It causes intense pain behind the eyes, which has been described as being worse than the pain associated with childbirth or kidney stones.
Attacks can occur multiple times in a single day and can last up to 3 hours. CH is rare, occurring in about 1 in 1,000 individuals, and is more common in men. As reported by medical News, Underdiagnosis is common ― especially in women.
The study drew on two Swedish population-based registries and included 3,240 patients with CH aged 16–64 years and 16,200 matched control persons. The analysis covered medical visits from 2001-2010.
Results showed that 91.9% of participants with CH had some type of multimorbidity. By comparison, 77.6% of the control group had some type of multimorbidity (odds ratio [OR]3.26; P < .0001).
Prior studies have shown a higher incidence of mental health and behavioral disorders among patients with CH. However, when the researchers removed those conditions along with external injuries from the dataset, patients with headache were still significantly more likely to have multiple co-occurring illnesses (86.7% vs 68.8%; OR, 2.95; P < .0001).
The most common comorbid conditions in the overall CH group were diseases of the nervous system (OR, 5.9; 95% CI, 5.46 – 6.42); 51.8% of the CH group reported these disorders, compared with just 15.4% of the control group.
Diseases of the eye, the respiratory, gastrointestinal, and musculoskeletal systems, and connective tissue were also significantly more common among patients with headache.
“For each diagnosis that we investigated, we found a higher incidence in the cluster headache group, and we thought this was a very striking finding and worth discussing in the clinical setting that these patients are at risk of general ill health,” Ran said.
Another novel finding was the higher rate of external injuries among the CH group compared with the control group. The finding seems to back up the theory that patients with CH are more likely to engage in risky behaviors, the researchers note.
In the CH group, external injuries were reported by 47.1% of men and 41% of women, vs 34.9% and 26.0%, respectively, in the control group.
“Now we can also show that CH patients have more injuries and that is totally unrelated to the biological health of the individuals, so that could also indicate higher risk taking,” Ran said.
Overall multimorbidity rates and diagnoses in each medical category except external injury were higher among women with CH than men with headaches. In addition, the mean number of days on sick leave and disability pension was higher among women with CH than among men with CH (83.71 days vs 52.56 days).
Overall, the mean number of sickness absence and disability pension net days in 2010 was nearly twice as high in the CH group than in the control group (63.15 days vs 34.08 days).
Removing mental and behavioral health disorders from the mix did not lower those numbers.
“Our numbers indicate that the mental health issues that are related to cluster headache might not impact their work situation as much as the other comorbidities,” Ran said.
Struggle is real
Commenting on the findings for Medscape Medical NewsHeidi Schwarz, MD, professor of clinical neurology at the University of Rochester Medical Center, New York, called the study a “valuable contribution” to the field and to the treatment of cluster headache.
“It’s a good study that addresses factors that really need to be considered as you take care of these patients,” said Schwarz, who was not involved with the research.
“The most salient features of this is that cluster headache is quite disabling, and if you add a comorbidity to it, it’s even more disabling,” she said.
Schwarz noted that CH is often misdiagnosed as migraine or is overlooked altogether, especially in women. These data underscore that although CH is more common in men, it affects women too and could lead to even greater disability.
“This has a direct impact on patient quality of life, and in the end, that really should be what we’re looking to enhance,” Schwarz said. “When a patient with cluster comes in and they tell you they’re really struggling, believe them because it’s quite real.”
The findings also fill a gap in the literature and provide the kind of data that could not be collected in the United States, she noted. Sweden provides paid sick time for all workers aged 16 and over and offers a disability pension to all workers whose ability to work is temporarily or permanently inhibited because of illness or injury.
“You will never get this kind of data in the United States because this kind of data comes from two datasets that are extremely inclusive and detailed in a society, Sweden, where they have a social support system,” Schwarz said.
The study was funded by the Swedish Research Council, the Swedish Brain Foundation, and Melby Gård, Region Stockholm, Märta Lundkvist stiftelse and Karolinska Institutet research funds. Ran and Schwarz report no relevant financial relationships.
Neurology. Published online December 14, 2022. Full article
Kelli Whitlock Burton is a reporter for Medscape Medical News covering neurology and psychiatry.
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