Cluster headaches are characterised by clusters of extremely severe headache attacks, and were formerly known as the neuralgia of Horton. 'Cluster' refers to the tendency of these headaches to occur periodically, with active periods being interrupted by spontaneous remissions.
The cause of cluster headaches is unknown. Hereditary factors may play a role. Vascular dilating substances such as alcohol and nitro-glycerine can provoke headache clusters. The same is also true of low oxygen levels, such as high in the mountains and during intercontinental flights.
Signs and symptoms
The headache is strictly unilateral and lancinating, boring and drilling in character, located behind the eye (peri-orbital) or in the temple, sometimes radiating to the neck or shoulder. It is accompanied by symptoms of autonomic deregulation with ptosis and miosis (Horner syndrome), conjunctival injection, lacrimation, rhinorrhea, and, less commonly, facial blushing, swelling, or sweating, all appearing on the same side as the headache. During attacks, patients are extremely restless and pace back and forth around the room. The duration of attacks can vary from 15 minutes to several hours. Strangely, the attacks start during the night and are probably related to the REM sleep phase.
After a cluster period, spontaneous remissions of several years can occur. In a small percentage of patients (15%), the cluster character can change into a chronic course with extremely severe attacks daily.
The neurological examination is frequently normal. However, accompanying symptoms of autonomic nervous system deregulation can be found.
Additional Somatic Diagnostics
The pattern of complaints is usually so typical that it is sufficient for diagnosis. Additional examinations (e.g., brain scans) to exclude other causes are rarely necessary.
- As in the case of migraine, the management of cluster headache consists of the prevention and treatment of attacks. Ergotamine, sumatriptan injections are active drugs in both migraine and cluster headache.
- It is important to consider that cluster headache occurs in episodic attacks and that prophylactic treatment should start as soon as possible. Medication can be stopped as soon as the cluster period ends.
- Some preventive drugs are not effective in cluster headache, but unfortunately are known to be prescribed. Well-known examples are carbamazepine and propanolol.
- Recently, it was demonstrated that twice-daily sumatriptan tablets were not effective.
- The treatment of episodic cluster headache includes oxygen inhalation, 100% oxygen, 7 litres per minute per mask.
- This one of the most effective, and by far the safest, treatment of episodic cluster headache attacks. In about 70% of cases, the attack is halted within 15 to 30 minutes. In addition, subcutaneous sumatriptan 6 mg is prescribed.
- Verapamil is an effective, and the safest, prophylactic drug. Its effect is known from daily practice. However, there are only a few known controlled studies.
- There is no evidence for the use of prednisone.
Interventional Pain Treatments
When treatment with drugs and oxygen inhalation fails, interventional pain treatment can be considered. This should preferably take place at the start of a cluster period.