Greater occipital nerve modulation and clinical aspects of cluster headache

Cluster headache is a relatively rare but extremely severe headache disorder. It consists of unilateral headache attacks lasting from 15 to 180 minutes that can occur as often as 8 times per day. The pain that is experienced during cluster headache attacks is one of the most intense forms of pain known. The impact of cluster headache on quality of life can be so severe that suicidal ideation occur in approximately 55% of people. This thesis describes several new, or lesser known, clinical aspects of cluster headache, such as unilateral sensitivity to light, risk-seeking behavior and the possible role of COVID-19 vaccinations in the occurrence of a new cluster episode. Furthermore, a relatively new treatment option, a greater occipital nerve injection with methylprednisolone, was studied. Finally, the long-term efficacy and tolerability of greater occipital nerve stimulation and possible factors associated with efficacy of greater occipital nerve stimulation are described.