Abstract and Introduction
Trigeminal autonomic cephalalgias include cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache attacks with conjunctival injection, tearing, and rhinorrhea (SUNCT). Conventional pharmacological therapy can be successful in the majority of trigeminal autonomic cephalalgias patients.
Most cluster headache attacks respond to 100% oxygen inhalation, or 6 mg subcutaneous sumatriptan. Nasal spray of sumatriptan (20 mg) or zolmitriptan (5 mg) are recommended as second choice. The bouts can be brought under control by a short course of corticosteroids (oral prednisone: 60–100 mg/day, or intravenous methylprednisolone: 250–500 mg/day, for 5 days, followed by tapering off the dosage), or by long-term prophylaxis with verapamil (at least 240 mg/day). Alternative long-term preventive medications include lithium carbonate (800–1600 mg/day), methylergonovine (0.4–1.2 mg/day), and topiramate (100–200 mg/day).
As a rule, paroxysmal hemicrania responds to preventive treatment with indomethacin (75–150 mg/day).
A short course of intravenous lidocaine (1–4 mg/kg/hour) can reduce the flow of attacks during exacerbations of SUNCT. Lamotrigine (100–300 mg/day) is the preventive drug of choice for SUNCT. Gabapentin (800–2700 mg/day), topiramate (50–300 mg/day), and carbamazepine (200–1600 mg/day) may be of help.
For many years, cluster headache (CH)[1–3] was considered a unique type of vascular headache with distinctive features. When paroxysmal hemicrania (PH) and short-lasting unilateral neuralgiform headache attacks with conjunctival injection, tearing, and rhinorrhea (SUNCT) were described, they were co-classified with CH owing to the similarities between all 3 syndromes. They share the clinical features of pain felt in the area supplied by the first division (V-1) of the trigeminal nerve, accompanied by a variable combination of cranial autonomic features.[1,2] Accordingly, the nosologic group was named trigeminal autonomic cephalalgias (TACs).
Although localization of the pain and autonomic accompaniments are similar, the 3 TACs essentially differ in duration, frequency, and temporal distribution of attacks, as well as in their precipitating mechanisms (Table 1).
Pathophysiologically, TACs are believed to essentially depend on the activation of the trigeminal system, responsible for the pain, together with a disinhibition of a trigeminofacial reflex responsible for the cranial autonomic accompaniments. This reflex pathway consists of a brainstem connection – at the superior salivary nucleus – between the trigeminal and the facial nerve.
Hypothalamic activation has been reported in all TACs.[8–10] The hypothalamus is anatomically connected to the pain modulating system and the superior salivary nucleus, and could therefore modulate both the pain and the autonomic accompaniments. Indeed, the regular and often expected cycling of CH bouts is thought to take place in the hypothalamus, where biologic clocks are located.
TACs are primary headaches. The clinical picture of TACs has been described in patients with documented intracranial structural lesions, mostly located in the posterior fossa and in the pituitary region.[11–14] The concurrence of TACs with any other disorder may likely occur purely by chance. Additional data, such as, for example, complete resolution of the symptoms after surgical/medical treatment of any structural lesion/disturbance may be needed to fortify the presumption of a symptomatic case. The possibility of symptomatic forms makes neuroimaging exams mandatory.
Diagnosis of TACs as primary provides the patients with reassurance but does not alleviate suffering. TACs are the most distressing of all primary headaches. The intensity of the pain is generally unbearable, and without effective treatment, the relentless recurrence of excruciating pain causes patients to feel hopeless, and even to think of suicide. Therefore, starting appropriate treatment is a matter of urgency, in order to mitigate the patient's pain.
The usual treatment of TACs (Table 2) provides absolute or substantial relief to most patients. Virtually, all patients with PH, and most CH patients, will benefit from the usual therapies. In contrast, only a few SUNCT patients may obtain satisfactory relief from noninvasive treatment. A minority of patients with refractory or intractable CH, as well as most SUNCT patients requires unusual, experimental, or invasive therapies. Here, we review the common therapies for TACs.
Headache. 2013;53(9):1401-1414. © 2013 Blackwell Publishing