Cluster Headache

Definition

Cluster headache is a severe primary headache disorder characterised by recurrent, unilateral headaches that occur in clusters. These headaches are extremely painful and often associated with autonomic symptoms.

Aetiology

The exact cause of cluster headaches is unknown, but they are believed to involve the hypothalamus, trigeminal nerve, and autonomic nervous system. Potential triggers include:

Alcohol consumption
Strong smells (e.g., petrol, paint fumes)
Seasonal changes

Pathophysiology

Cluster headaches are associated with activation of the trigeminal-autonomic reflex, resulting in severe pain and autonomic features such as lacrimation and nasal congestion. The hypothalamus is thought to play a key role in their pathogenesis.

Risk Factors

Male gender
Age (typically begins between 20 and 40 years)
Family history of cluster headaches
Smoking

Signs and Symptoms

Severe unilateral headache, typically around the eye
Lacrimation (tearing)
Rhinorrhoea (runny nose)
Ptosis (drooping eyelid)
Miosis (constricted pupil)
Restlessness or agitation

Investigations

Clinical history and headache diary
Neurological examination
Neuroimaging (MRI or CT scan) to rule out secondary causes

Management

Primary Care Management

Initial assessment and diagnosis
Education and support for patients and caregivers
Prescribing acute treatments (e.g., sumatriptan, high-flow oxygen)
Referral to a specialist for further management if needed

Specialist Management

Acute treatments: Subcutaneous sumatriptan, high-flow oxygen therapy
Preventive treatments: Verapamil, corticosteroids, lithium
Management of refractory cases: Greater occipital nerve blocks, neuromodulation therapies
Monitoring and adjusting treatment plans based on response

Example Management for Cluster Headache

A patient presenting with cluster headache should receive acute treatment with high-flow oxygen (12-15 L/min for 15-20 minutes) or subcutaneous sumatriptan (6 mg). Preventive treatment with verapamil should be initiated, starting at a low dose (80 mg three times daily) and gradually increasing based on tolerance and response. Patients should be educated about avoiding known triggers and provided with a headache diary to monitor the frequency and severity of attacks. Regular follow-up appointments are necessary to adjust the treatment plan as needed.

References

NICE. (2024). Headaches: Diagnosis and Management of Headaches in Young People and Adults. Retrieved from NICE
NHS. (2023). Cluster Headaches. Retrieved from NHS
Goadsby, P. J., & Sprenger, T. (2010). Cluster Headache. New England Journal of Medicine.
May, A., & Leone, M. (2003). Cluster Headache: Pathogenesis, Diagnosis, and Management. The Lancet Neurology.
International Headache Society. (2023). The International Classification of Headache Disorders, 3rd edition. Retrieved from IHS