Occipital neuroma triggered cluster headache responding to greater occipital nerve blockade.

Dr. Fabrizio Di Stani – Dipartimento di Scienze Neurologiche / Università di Roma “La Sapienza” Roma, Italy. E-mail: [email protected] Cluster headache (CH) is characterised by attacks of severe unilateral pain in the orbital, supraorbital and/or temporal areas that last from 15 to 180 min, with recurrence up to 8 times daily and accompanied by ipsilateral autonomic symptoms. Although effective acute treatments are available for CH attacks (e.g. subcutaneous sumatriptan injections), most patients also require preventive therapy. Several drugs, such as verapamil, methysergide and lithium carbonate, have proved to effectively prevent CH attacks and shorten bouts. Oral steroids are considered to provide the most effective transitional preventive treatment, though they may provide limited relief in some cases; moreover, some patients become steroid-dependent and develop serious steroid-related adverse effects within months. CH is marked by its circadian rhythmicity. Episodic cluster periods start at the same time each year, occur at the same time each day and the duration of each CH is almost the same for every attack. These clinical features, along with the hormonal alterations documented in CH patients, suggest that the hypothalamus plays a role in the genesis of CH. PET studies by May et al., revealed hypothalamic activation during CH attacks, supporting the hypothesis of hypothalamic involvement. The concept of the hypothalamus acting as a CH generator has also been entertained. However, not all CH patients present the same symptoms, nor do all respond to the same medications, which suggests that atypical or even non-hypothalamic forms of CH may exist. Although the cervico-occipital onset of CH is not contemplated by the International Headache Diagnostic Criteria II-version (IHDC II), it is not uncommon to find patients with this painful symptomatology in clinical practice. Anatomical and clinical data suggest that the greater occipital nerve (GON) may trigger pain that has the typical cluster characteristics and is associated with the autonomic symptoms noted in CH. Sensory neurons in the trigeminocervical complex receive ipsilateral and contralateral input from the GON. We describe an atypical cluster headache with trigeminal symptoms that improve after the blocked of the greater occipital nerve in one patient with occipital neuroma.