Cluster headache is one of the most severe types of headaches. The clustered nature of the headache attacks is its distinctive feature and is the reason for its name.
During the attack phase of the headache, the headache attacks frequently and can last for weeks or months, and then goes into complete remission without pain. These two periods are spaced apart. Different people with cluster headaches may have different types of headache attacks, but most patients have one cluster phase in a year. After entering remission, some people often do not have a single attack for months or even years.
Cluster headaches are very intense during an attack, with intense, brief, severe unilateral drilling pains. It can even make people feel like they are going to be unable to pull through. Unlike migraine, the headache is mostly confined and fixed to one side of the orbit, behind the ball and in the frontotemporal region. The onset is often at night and wakes the patient up in pain. The onset of the headache may be sudden and without aura. It may be a burning sensation in one side of the nose or pressure behind the bulb, followed by pain in a specific area, often unbearable, and facial flushing, conjunctival congestion, lacrimation, runny nose, and nasal congestion. The trigger can be alcohol consumption, excitement or vasodilators during the attack clusters. The age of onset is between 20 and 40 years. The ratio of male to female is about 4:1, and family history is rare.
I. Etiology of cluster headache
Many patients who come to outpatient clinics for headache first worry that their headache is caused by an underlying disease or even a dangerous disease. However, most headaches, even severe ones, are actually primary headaches, i.e., they have no specific cause. However, when a new headache appears, or when an existing headache suddenly changes, the headache may also be caused by a serious underlying disease (e.g., cerebrovascular abnormality, brain tumor, brain hernia, etc.). This should be clearly stated at the time of the visit to the doctor.
The International Headache Society classifies cluster headaches into two categories: paroxysmal and chronic, depending on the length of the attack and remission period. Paroxysmal cluster headaches can last anywhere from a week to a year, with daily attacks and periods of remission of at least a month between attacks. Chronic cluster headache has an entire attack period of more than a year, with a remission period of no more than a month. Headache attacks also occur daily during the attack period.
The percentage of people with cluster headaches who have chronic cluster headaches is about 10-15%. Some chronic headaches develop slowly from paroxysmal headaches, while other chronic headache sufferers develop suddenly without any history of headaches. In addition, some patients may alternate between paroxysmal and chronic headaches. Two diagnoses of headache may be given to such patients.
Current medical experts believe that cluster headaches may be the result of a combination of the following factors.
1. Trigger: Many patients are alcohol and tobacco addicts, and during a headache attack, drinking alcohol has the potential to trigger a severe headache in just a few minutes. Other possible triggers include taking nitroglycerin and having a disrupted normal resting schedule. Some may also be related to sleep apnea conditions.
2. Increased sensitivity of nerve conduction pathways: Cluster headaches occur in the area behind the eyes and in the surrounding area, which is controlled by the trigeminal nerve. When the trigeminal nerve is stimulated, it causes an abnormal response in the arteries supplying blood to the brain, causing these vessels to dilate, thus producing pain.
3. Abnormal function of hypothalamus: The timing of cluster headache attacks is often very regular and the attack cycle is also related to the seasons, which indicate that the attacks of cluster headache are related to the biological clock in the human body, that is, the hypothalamus. One of the functions of the hypothalamus is to control the sleep-wake cycle and other internal rhythms of the body. Abnormalities in hypothalamic function may well explain the periodicity and regularity of cluster headache attacks. Scientists have detected a significant increase in hypothalamic activity during cluster headache attacks, and this activity is not present in other forms of headaches such as cluster headache.
II. Symptoms of cluster headache
Cluster headache attacks are rapid and often have little aura. Within minutes of the attack, the pain may become very intense. Most patients with the same cluster episode of pain usually occur on the same side of the head only and often never change position for the rest of their lives. Cluster headache attacks can be a sharp, pins-and-needles or burning pain that feels like a hot poker is stuck in the eye or the eye is being pushed out of its socket.
Unlike migraines, people with cluster headaches are often reluctant to lie down during an attack because it aggravates the pain. Many sufferers may scream, bang their heads against the wall, or even hurt themselves during an attack.
Cluster headache attacks are seasonal, such as only occurring in the spring or fall, or starting shortly after the summer or winter solstice, the day with the longest or shortest daylight hours.
Prevention of cluster headache
Prevention of headache includes helping to reduce the frequency, severity and risk of recurrent headache attacks. Preventive medications for headache can generally be divided into short-term preventive medications and long-term preventive medications. Short-term medications work quickly, but may have adverse side effects. Long-term medications have a slower onset of action but can be used safely throughout the headache episode.
The main purpose of short-term preventive medication is to provide temporary prevention until the long-term preventive medication takes effect. The main short-term preventive medications are corticosteroids and ergotamine. Alternatively, nerve blocks may be effective as short-term prophylaxis, especially in patients who are unable to tolerate other medications.
1. Occipital nerve block anesthesia and supraorbital nerve block anesthesia.
2. Ergotamine, sublingual tablets and rectal suppositories. It can be used at bedtime to prevent nighttime headache attacks. Ergotamine is safe and effective for short-term use, but should not be used for more than 3 weeks to avoid serious side effects.
3.Corticosteroid, a preventive drug that can work quickly. It is mainly used for new headache patients or patients with very short attacks and long remission periods.
Long-term prophylactic drugs can be used safely throughout the attack period. Some patients with chronic cluster headache may not respond well to a particular chronic preventive medication, in which case the physician may recommend two or more long-term preventive medications at the same time.
There are two main categories of these long-term preventive medications.
1. calcium channel blockers such as verapamil, often used as the drug of choice for the prevention of cluster headache, although its mechanism of action is not well understood. This medication is usually taken from the beginning of the attack and continued until three to four weeks after the end of the attack, sometimes for longer periods. The dose is then gradually reduced under the direction of a doctor until it is completely discontinued. A common side effect of this medication is constipation, in addition to possible adverse effects such as dizziness, nausea, weakness, ankle edema, and low blood pressure.
2. Lithium is generally used to treat bipolar disorder, but it is also effective in preventing chronic cluster headaches.
Other measures that can help avoid cluster headache attacks are
1. Have a regular work and rest schedule.
2. Avoid lunch breaks.
3. Do not smoke or drink alcohol, including beer and wine.
4.Avoid exposure to volatile substances such as solvents and gasoline.
5.Avoid going to high altitude areas.
6.Avoid dazzling light.
IV. Treatment
Cluster headache cannot be completely cured yet, so the goal of treatment is mainly to help patients relieve the level of pain and shorten the duration of pain. However, a new method of pulsed radiofrequency neuromodulation has been shown to be effective for up to three years or more.
Medications: Medications and methods used to provide acute pain relief include
1. Sumatriptan: When using sumatriptan it can be administered by injection or by nasal spray. Use with caution in headache patients with cerebral ischemia and hypertension.
2. Hydroergotamine: including intravenous infusion, injection, and nasal inhalation.
3. Octreotide (Zhentermine): It is a synthetic growth inhibitor for the brain and was previously used to treat severe diarrhea. It was later found that octreotide injection can also be used to effectively treat cluster headache, and it is safe for headache patients who also suffer from hypertension or cerebral ischemia.
4. The local anesthetic lidocaine can be used as a nasal drip to effectively combat cluster headache.
5. Oxygen: Inhalation of 100% pure oxygen at a rate of 6 liters per minute through a mask can provide significant pain relief.
Surgery and minimally invasive treatment Surgery is generally considered only when medication is not effective or when the patient cannot tolerate the side effects of the medication. It is also more suitable for patients whose headaches always occur on the same side.
1. Neurosurgery: This is the removal of part of the trigeminal nerve with a scalpel, or the burning of part of the trigeminal nerve with a small electric knife. This procedure can provide relief for most patients with chronic cluster headaches.
2. Gamma knife surgery: The surgeon uses a beam of radiation that can be pinpointed to destroy part of the trigeminal nerve. Radiosurgery is a non-invasive procedure and therefore has fewer side effects than conventional surgery, but there are questions about its effectiveness and longevity.
3. Pulsed radiofrequency trigeminal nerve-related meningeal branch modulation: Since cluster headache is a trigeminal autonomic neuropathic headache, with reference to the principle and efficacy of surgery and gamma knife to cut off part of the trigeminal nerve and destroy part of the trigeminal nerve, pulsed radiofrequency is used to act on the trigeminal nerve without either removing the nerve or destroying the nerve. Compared with the first two surgical methods, it is more convenient, easy to perform, safe and effective. There is usually no residual weakness of the jaw muscles. Sensory loss in the head and face is also relatively mild.