What Are Cluster Headaches?Cluster headache is a severe type of headache that occurs in a cluster, or cyclical pattern. Cluster headaches are characterized by recurrent, short-term attacks of intense unilateral pain, usually around the eye, that typically lasts between 15 and 180 minutes. The pain may radiate to other areas including the face, head, neck, and shoulders. Other autonomic symptoms may occur during a cluster headache, including nasal congestion, lacrimation, ptosis, lid edema, miosis, and eye redness. Patients suffering from cluster headaches may also experience severe restlessness or agitation during an attack.
Episodes of frequent attacks, known as cluster periods, may last from weeks to months, followed by periods of remission. During a cluster period, headaches may occur every day and some patients may experience several headaches through the course of one day. Often, the headache episodes happen at the same time each day, with the majority of headaches occurring at night.
Cluster headaches are relatively rare, with estimates of cluster headache being 0.5-1 /1,000. Cluster headaches tend to affect young adults, with initial attacks commonly occurring in the third decade of life. Males are more commonly affected than females, though the gap is decreasing, which may be due to the increased recognition of this condition in females.
While the symptoms of cluster headaches are severe and distressing to patients, the condition is non-life threatening and there are treatments that are available to help decrease the severity and intensity of headache symptoms. Additionally, there are also prophylactic treatments available that can help to prevent cluster headache episodes.
Causes Of Cluster HeadachesThe exact cause of cluster headaches remains unknown. However, it is hypothesized that abnormalities in the hypothalamus may play a role. Cluster headaches tend to follow a cyclical pattern through the course of the day, and this cyclical pattern often follows the seasons of the year. These cyclical patterns suggest that the body’s biological clock is involved in this headache disorder, and this is controlled by the hypothalamus. Therefore, abnormalities in the hypothalamus may explain the timing and cyclical pattern of cluster headaches.
Imaging studies have found that there is increased activity within the hypothalamus during a cluster headache attack, which supports the notion that the hypothalamus is involved in this disorder.
In regard to triggers for cluster headaches, alcohol is the only dietary trigger that has been identified. However, strong odors, including cigarette smoke and solvents, as well as napping, may also trigger cluster headache attacks. Interestingly, in between cluster periods, patients may be able to drink alcohol and smoke without triggering an attack.
Risk factors that have been identified for the development of cluster headaches include:
- Sex: Men are more likely to suffer with this headache disorder
- Age: Although this condition can develop at any age, individuals between the ages of 20 and 50 are most at risk for developing this condition
- Smoking status: Many individuals who are diagnosed with cluster headaches are smokers
- Alcohol: Use of alcohol can trigger a cluster headache
- Family history: Having a parent or sibling with cluster headaches increases an individual’s risk of developing this condition
Treatments For Cluster HeadachesIn order to diagnose cluster headaches, physicians will take a detailed history of symptoms and perform a neurological examination. Imaging tests, such as magnetic resonance imaging (MRI) and computed tomography (CT), may also be ordered. At the present time, there is no curative treatment for cluster headaches; treatment aims to decrease the severity of the headaches, decrease the duration of the headaches, and prevent the headaches from occurring.
For the management of acute attacks of cluster headaches, rapid-acting treatments are preferred as the pain associated with cluster headache episodes is severe. The two most efficient treatments are high-flow inhaled oxygen and subcutaneous sumatriptan. Subcutaneous sumatriptan (Imitrex, Imiject) has shown to effectively relieve cluster headache pain. Intra-nasal sumatriptan and zolmitriptan may be used if a patients refuses injections. High-flow inhaled oxygen through a mask has also been shown to provide effective relief of cluster headache pain and is especially useful for patients who are unable to use triptans.
Other treatments that may be used for the management of an acute cluster headache attack are ergotamine and dihydroergotamine. However, these medications cannot be combined with triptans within the same 24-hour period. Additionally, intra-nasal application of topical lidocaine may be utilized, although its efficacy has not been well documented.
Prophylactic treatment aims to reduce the frequency of cluster headache episodes. Verapamil, which is a calcium channel blocker, is the leading treatment choice for the management of cluster headaches. Side effects include fatigue, weakness, conduction heart block, and lower extremity edema.
Corticosteroids may be recommended for short-term relief of symptoms. However, the side effects associated with this medication including diabetes, hypertension, and cataracts, which make it an unsuitable option for long-term use.
Greater occipital nerve blocks are another treatment that may help to manage cluster headaches. The nerve block involves injecting a corticosteroid, sometimes mixed with a local anesthetic, into the area of the greater occipital nerve (midway between the mastoid and the occipital protuberance) to help relieve inflammation and pain.
Other pharmacological options for treating cluster headaches include lithium, methysergide, topiramate, and valproic acid. Additionally, manual therapies including massage therapy, physiotherapy, and chiropractic care may be effective. However, further research is needed to support this recommendation.
In rare cases, doctors may recommend surgery for patients suffering from cluster headaches that have been unresponsive to treatment, or to patients who are unable to tolerate medication side effects. Surgical procedures for the treatment of cluster headaches aim to damage the nerve pathways that are believed to be responsible for pain, most commonly the trigeminal nerve. However, the long-term effectiveness of surgery for cluster headaches remains a source of dispute. Additionally, there are various complications associated with surgery, including muscle weakness and loss of sensation.
ConclusionCluster headaches are a severe type of headache that is quite rare, most commonly affecting young adult males. Usually pain is on one side of the head, commonly around one eye and is sometimes accompanied by other symptoms including nasal congestion, lacrimation, ptosis, lid edema, miosis, and eye redness.
Treatment for cluster headaches focuses on reducing the intensity and duration of symptoms, as well as preventing cluster headache episodes. There are various pharmacologic treatment options available to patients suffering from this headache disorder. Furthermore, surgery may be recommended in rare cases. Patients suffering with cluster headaches should speak with their physicians about the best course of treatment for their condition.
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