Cluster Headaches

Cluster headaches can be further divided into two different subtypes, chronic and episodic. As mentioned above, cluster headaches that happen constantly for a continuous period of time—sometimes even longer than a year—and then disappear for about a month are known as chronic cluster headaches.

On the other hand, cluster headaches that occur for a lesser period of time—usually between a week up to a few months at a stretch—and then disappear for more than a month are called episodic cluster headaches. However, it is not necessary that a person with one type of cluster headaches cannot develop the other.

The consistent, constant nature of these headaches is what sets them apart from other types of common headaches. While the headaches are usually limited to one side of the forehead or above the eye, sometimes the pain can switch from one side of the head to the other. On some occasions, the pain can also spread to other parts of the body including the nose, neck, teeth or even the shoulder on the same side of the body.

Even though cluster headaches are rare, they can be much more intense than a headache from a migraine. They tend to be more common among men and are known to occur in a person in their 30s or 40s. The severity of the pain tends to bring out a strong reaction from the person suffering it—patients usually respond by constantly pacing around a room, rocking back and forth or even trying to hit their head against something in an effort to bring down the pain.

Some of the symptoms of cluster headaches include:

• Pain around the forehead, temple or above the eye
• Sweating from the face and forehead
• Stuffy or blocked nose
• Reddening, watering or tearing in the eye on the side where the pain is emanating from
• Drooping or swollen eyelid on the side that is hurting
• Constricted pupil in the eye on the side that is hurting
• Light sensitivity
• Nausea
• Restlessness

Cluster headache is described as a form of primary neurovascular headache, but its exact cause or pathophysiology is not well established. However, some researches have previously shown that during such an attack, activity in the hypothalamus in the brain is higher. It is the part of the brain that controls the body's temperature and urges such as hunger and thirst.

But even though a definitive cause is yet to be ascertained, there are some factors that can trigger such an attack:

• Smoking and alcohol consumption
• Exposure to bright lights
• Increased physical activity, especially in the heat
• Exposure to heat from direct sunlight or hot baths that can rapidly increase body temperature
• Reaction to certain medications or narcotics

Aside from the above mentioned probable factors, rapid changes in temperature of a particular region, especially during autumn and spring have also been known to trigger attacks among residents in certain areas.

Researchers have also observed unusually high levels of cortisol and melatonin, two hormones responsible for controlling the body's stress and sleep and wake cycles, respectively.

There aren't any specific known causes behind cluster headaches. Still, certain preventive measures—minor lifestyle changes—are considered helpful in reducing the risk of the onset of the symptoms:

• Avoid alcohol and smoking; a large number of people who suffer from cluster headaches are smokers
• Avoid exercising or exerting yourself in the heat or hot weather, especially outdoors
• Certain medications can cause blood vessels to dilate. Talk to your doctor about changing these medications to avoid cluster headaches
• Follow a consistent sleeping pattern
• Some preventive medications have also been known to alleviate the symptoms, but according to a 2015 study, some patients (10-20% of them) can develop resistance to them. These medicines include corticosteroids, calcium-channel blockers, nerve blockers and bipolar disorder medicine Lithium carbonate.

The severe nature of cluster headaches is enough reason for a person to get it checked by a doctor, who generally performs a physical exam and asks for the patient’s symptoms and medical history. 

The peculiar nature of the condition usually points to this condition, but the doctor may further suggest tests such as a neuro exam or imaging tests such as CT scans or MRIs to rule out the presence of tumours.

Even though cluster headaches are a rare phenomenon and are likely to affect one in 1,000 people, the symptoms and resulting pain are quite severe. Some preventive medications, however, can help keep the frequent headaches at bay.

Medicines that can prevent the onset of a severe attack include blood pressure medications that can relax the blood vessels. One of the proposed reasons behind cluster headaches is dilation or widening of blood vessels that are responsible for supplying blood to the brain and the facial muscles.

Certain steroids can also help keep cluster headaches down to a minimum as they help in controlling the inflammation, and antidepressants or muscle relaxants can also help in some instances. Over the counter pain medications haven't been known to alleviate the symptoms.

Along with preventive measures to control the onset of severe pain due to cluster headaches, there are certain medications and treatment methods that can help alleviate the resulting pain. 

Breathing in 100% pure oxygen through a mask has also been known to provide relief from cluster headaches, especially when there is a headache coming on. (Read more: Oxygen therapy)

Certain drugs that are used to treat the symptoms of migraines have also been effectively used to reduce the symptoms of cluster headaches. Medications through injections (injectable sumatriptan) or nasal sprays that help constrict the blood vessels can help ease the headaches. Topical pain-relieving creams can also be applied to the area that is hurting to provide some relief.

If none of the above mentioned treatments works to alleviate the symptoms or bring relief to the patient, doctors may recommend surgery, one of which involves the use of a neurostimulator, which delivers small electrical signals to a nerve in the neck. Some patients who do not respond to conservative treatments can benefit from nerve stimulation.