Cluster headaches, sometimes known as suicide headaches due to the level of pain experienced, are unbearable severe headaches, often unilateral, and centred around one eye. They're called cluster headaches because they usually come in clusters of headaches. For example, someone can have multiple attacks a day (each lasting 15-180 minutes and rapidly subsidise), for many consecutive days-months, followed by months-years of being headache-free.
Cluster headaches are the most common condition falling under trigeminal autonomic cephalalgias which are thought to be due to the trigeminal autonomic reflex.
🔢 Classification
- Episodic cluster headaches - these are cluster headaches that last 7 days - 1 year and are separated by pain-free periods of at least 3 months.
- Chronic cluster headaches - these are cluster headaches that last for ≥1 year without remission or remission periods of less than 3 months.
We can also classify the headaches by their aetiology:
- Primary headaches - headaches that are not associated with an underlying condition (such as trigeminal autonomic cephalalgias).
- Secondary headaches - headaches associated with another local/systemic condition.
Pathophysiology
The aetiology of this condition is not known, but there some factors that are associated with these headaches:
- Alcohol consumption
- Smoking - but smoking cessation has no effect on this condition
- Head trauma
- Seasons - more attacks happen in spring and autumn
The pathogenesis is complex and not fully he 3 cardinal features of the disorder are:
- Trigeminal distribution of the pain
- Ipsilateral cranial autonomic symptoms - such as ptosis, miosis, conjunctival injection, lacrimation, rhinorrhoea, nasal congestion.
- Circadian/circannual pattern of attacks - a distinct pattern linked to time of the day or time of the year.
The trigeminal autonomic reflex has a significant role in the pathophysiology of the disease and the factors above may trigger this reflex.
- The stimulated pain afferent (sensory) trigeminal fibres → relay the pain signal to the CNV nucleus in the brainstem → to the thalamus (the location of pain perception).
- In addition, the trigeminal fibres relay this signal to certain CNV nuclei in the brainstem that activate the parasympathetic pathways → lacrimation, rhinorrhoea, nasal congestion, conjunctival injection.
- The posterior hypothalamus also has an inhibitory effect on the sympathetic pathways → miosis and ptosis.
It is thought that the posterior hypothalamus is activated due to cavernous sinus vascular changes leading to subsequent irritation of the local plexus of nerve fibres → sympathetic symptoms.
⚠️ Risk factors
- Male gender
- Family history
- Head injury
- Cigarette smoking
- Alcoholism
😷 Presentation
Each attack usually lasts 15-180 minutes before rapidly subsiding. The attack may wake the patient from sleep and this usually happens 90-120 minutes after falling asleep.
- Severe headache around the eye - the pain is described as sharp, pulsating, and feel as if something is pressing in the back.
- Vomiting
- Agitation and restlessness - patients might pace back and forth, vocalise, or bang their head against the wall.
Associated autonomic symptoms are typically unilateral & ipsilateral:
- Red, swollen and watering eye
- Pupil constriction (miosis) and eyelid drooping (ptosis) - also known as partial Horner syndrome.
- Nasal discharge
- Facial sweating
🔍 Investigations
- ⭐️ This is a clinical diagnosis, based on the history and normal neurological examination, as it is important to rule out other causes of headache.
🧰 Management
🚨 Acute attacks
Treatment options during acute attacks are:
- 🥇 Short-burst oxygen therapy - this is high-flow 100% oxygen at a flow rate of 12–15 L/min via a non-rebreather face mask for 15 to 20 minutes (may be kept at home).
- 🥇 Triptans
- Sumatriptan - either subcutaneous injection or intranasal spray.
- Zolmitriptan - as an intranasal spray.
- Non-invasive vagus nerve stimulation - using a handheld, patient-controlled, non-invasive vagus nerve stimulator that is applied to the skin of the neck. NICE does not have this in their recommendations, but it has shown to be effective:
⚠️ Paracetamol, opioids, NSAIDs, and oral triptans should not be recommended in the acute management of a cluster headache
🔮 Prophylaxis
- 🥇 Verapamil