Cluster headaches are excruciatingly severe headache episodes that come and go in repeating cycles throughout the year with periods of remissions in between.
They are rare types of headaches occurring in a cluster or group. Individuals experience brief episodes of excruciatingly severe headaches lasting for one to three hours at every cluster headache attack. Similarly, they can recur about one to eight times a day and last for weeks to months. The attack period is followed by a period of remission when the individual is free of headaches, and then another cycle of cluster headaches commences. This pattern runs in a cycle. Pain associated with cluster headaches is said to be the most severe type of headache among all the existing types of headaches. It has a sharp, piercing, and stabbing nature and badly affects one’s day-to-day activities and work.
The typical symptoms of cluster headaches are:
Drilling, burning type of pain on one side of the head.
Pain starts in the temple area, behind the eye, or around it.
Usually, it begins at night, waking one up from sleep.
Occasionally, the side affected may change in the next attack.
Puffed up watery eyes that keep tearing up the entire time of the attack.
Redness in the eye.
Runny nose or stuffy nose.
A flushed face that keeps sweating.
On the affected side of the head, the pupil of the eye looks shrunken, and the eyelids droop.
One tends to stay agitated and restless throughout the episode; choose to pace around in the room, rock the torso, compress the painful side or bang the head.
The pain might end abruptly, leaving the affected exhausted.
Often one shows aggressiveness, anxiety, and depression during cluster bouts; rarely, some individuals show suicidal tendencies.
Cluster cycles come and go roughly one to two times in a year, and most of the time, one can predict the attack. For most people, it happens during the same season every year. Each episode lasts approximately fifteen minutes to three hours. Depending on the individual, it may happen once daily, multiple times in a day, or on alternate days. For individuals with a long-lasting (chronic) problem, cluster bouts last for about a year, with remissions of less than a month.
People between the age group 20 to 40 seem to have a higher prevalence of cluster headaches, while men have slightly higher chances than women. Sometimes cluster headaches are passed on from one generation to the next among families. Individuals who suffered injuries to the head also have higher chances of developing cluster headaches. The exact cause of cluster attacks is yet to be identified. However, it seems to relate to the sudden release of certain chemicals in the body, such as histamine or serotonin. The blood vessels in certain areas inside the brain (trigeminal nerve) seem to get dilated. It is also linked to the activity of the organ hypothalamus in the brain that controls the biological clock of body functions.
Apart from this, a few factors may trigger a cluster bout. They are:
Excessive consumption of alcohol.
Exposure to bright lights.
Watching screens for a prolonged period.
Exposure to strong, pungent smells.
Being in high-altitude terrains.
Heavy exercise or physical exertion.
Increased sexual activity.
Increase in body temperature due to weather, exertion, or a hot bath.
Overuse of cocaine.
Consuming certain food types that contain nitrates.
Many times, cluster headaches get misdiagnosed as migraine disorders. It is often observed that during a migraine attack, people have a tendency to stay still and get confined to a dark and quiet room, but cluster headaches cause them to keep moving around and stay agitated. Besides, cluster headache attacks last for shorter durations compared to migraine attacks.
Identifying cluster headaches clinically requires a meticulous assessment process. Analyzing the medical history, signs, and symptoms are significant. Based on these, the doctor will try to figure out the underlying cause for cluster bouts. In addition, there will be a neurological assessment. One should rule out any other types of headaches as well. Imaging studies of the brain and blood vessels in the head also help evaluate it. Computed tomography scans (CT) and magnetic resonance imaging (MRI) help to rule out other conditions that cause headaches, such as brain tumors.
If left untreated, there is a chance they increase both in duration and frequency. Hence, treatment includes immediate measures to relieve the symptoms and stop a cluster attack and ways to reduce the frequency and duration of future occurrences.
Following are the acute treatment strategies:
At the time of the headache episode, a facemask with high-flow oxygen is effective in ending the attack.
The doctor may prescribe steroid tablets or injections such as Prednisone to relieve the initial symptoms of cluster headache.
Some migraine medications, such as Sumatriptan, Zolmitriptan (nasal spray), and Dihydroergotamine, are effective in stopping cluster bouts. These medicines help constrict the blood vessels in the brain, which eases the pain. Injectable medications are preferred over oral tablets for faster effect, as this type of headache gathers maximum intensity within minutes of onset.
For some affected individuals, sending electrical stimulation into the head to terminate the attack is effective (transcutaneous vagus nerve stimulation).
Local anesthetic injections (occipital nerve block) around the nerves in the back of the head give relief to some people.
Preventive strategies include:
Calcium channel blockers like Verapamil are prescribed to prevent cluster headaches from occurring.
Antiseizure drugs, Melatonin, and Lithium are effective in reducing the frequency of cluster headaches.
Finding the association between individual triggers that cause a cluster attack helps with future prevention. Keeping a journal on one’s lifestyle, habits, and food intake is an excellent way to explore the individual triggering factors since triggers vary from person to person. Often, avoiding the triggers is the best way to prevent cluster headaches.
Though relatively uncommon, cluster attack is a debilitating type of headache disorder that requires an accurate diagnosis to implement the right kind of treatment. In addition, understanding the attack pattern is critical in effective prevention since they recur almost every day for days, weeks, and months. Finally, an important fact to remember is that cluster headache is not life-threatening and does not damage the brain. And for most people, the condition gets better with age.
Last reviewed at:
02 Aug 2022 - 4 min read
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