Man With Multiple Short-Lasting, Unilateral Daily Headaches

THE DIALOGUE:

Primary care doctor: On what basis should the diagnosis be made in this case?

Headache specialist: The diagnosis of a primary headache disorder usually cannot be made or verified based on any available diagnostic methods, such as MRI or MRA. Thus, the clinical peculiarities of the headache—as noted in a complete history—should facilitate the diagnosis.
    The pattern of this patient’s headaches bears close scrutiny. His headaches have certain clinical features that suggest a group of chronic headache syndromes characterized by attacks that are short-lasting, frequent, and unilateral (Table 1). Initially, attention needs to be directed to the most typical and the most unusual headache signs for this patient—such as the duration of the acute attack, the frequency, and the location.
    This patient complains of headaches that last about 20 to 40 seconds and occur 40 to 60 times daily. The headaches always occur on the right side. These features suggest that the patient has one of a specific group of headaches that includes episodic and chronic paroxysmal hemicrania, short-lasting unilateral neuralgiform headaches with conjunctival injection and tearing (SUNCT syndrome), idiopathic stabbing headache, cluster headache, and trigeminal neuralgia.

Primary care doctor: What clinical features distinguish these headache types from each other?

Headache specialist: To establish a differential diagnosis, consider the exact duration of the headache attack and the exact frequency of the headache episodes. Minor clinical details can play a dramatic role in establishing the diagnosis. It is crucial to clarify the duration of the acute headache episode, which differs from one headache type to another (see Table 1).

Primary care doctor: If the clinical features of these headache types are so similar, can they all be treated in the same manner?

Headache specialist: Unfortunately, no; treatment differs for each headache type. Certain medications produce a dramatic effect in some of these headache types but have no effect in others.
   In some patients, a dramatic response to medication can be part of the diagnostic process; for example, indomethacin is the treatment of choice for the chronic and episodic hemicranias and is considered the sine qua non for establishing the diagnosis.¹ However, we are not certain how best to treat other headache syndromes with similar presentations.

Primary care doctor: What is the diagnosis in this patient?

Headache specialist: He almost certainly suffers from SUNCT syndrome. This diagnosis is based on the unilateral pain, its severity, the significant associated autonomic signs (unilateral conjunctival injection and lacrimation), and the normal MRI and MRA results.
    SUNCT syndrome is the rarest type of primary headache disorder. Sjaastad and colleagues² first described it in 1978. This disorder has male predominance (2.25:1). The mean age of onset is 51 years (range, 23 to 77 years).³
    Typically, the headache is unilateral and located around the eye with radiation to the ipsilateral temple or forehead. Patients describe the headache as severe burning, stabbing, or throbbing pain that can occur up to 100 times a day. The acute headache attack is brief (15 to 120 seconds).³ The headache is always associated with conjunctival injection and lacrimation on the ipsilateral side.
    Symptomatic periods usually last from a few days to a few months. The headache may then resolve without any special treatment. Remissions may last from a few days to several months or even years.
    The clinical criteria for the diagnosis of SUNCT syndrome were suggested by Goadsby and Lipton⁴ in 1997 (Table 2).

Primary care doctor: What causes SUNCT syndrome?

Headache specialist: The exact cause and pathogenesis are still unknown. Secondary causes of SUNCT syndrome have been reported in 3 patients.^5-7

Primary care doctor: What are the treatment options?

Headache specialist: Unfortunately, SUNCT syndrome is remarkably refractory to treatment. Unlike some other short-lasting headache syndromes that are highly responsive to indomethacin—such as the episodic and chronic hemicranias and hypnic headache—SUNCT syndrome does not usually respond to this medication. Moreover, other medications used to treat migraine—such as triptans and agents that contain ergotamine—are also usually ineffective in SUNCT syndrome. Some reports show that carbamazepine( is helpful.³ Other case reports have demonstrated modest efficacy with sumatriptan(, valproate, prednisone, and lamotrigine(.^8,9 The patient in this case had some success with oxygen therapy.

Primary care doctor: Why do primary care clinicians need to know about SUNCT syndrome?

Headache specialist: Although SUNCT syndrome is rare, it can easily confuse the physician and thus lead to misdiagnosis of another type of headache disorder, such as cluster headache, chronic or paroxysmal hemicrania, trigeminal neuralgia, or idiopathic stabbing headache. Considering the severity of the pain syndrome in all these conditions, the high frequency of headache attacks, and the potential for patients to be disabled, it is crucial to differentiate among these pain disorders and implement the appropriate treatment. Patients with SUNCT syndrome are best referred to a headache specialist.