Differential Diagnosis and Prognosis of Tension-Type Headaches

Jean Schoenen

Rigmor Jensen

DIFFERENTIAL DIAGNOSIS

According to the second edition of the International Headache Society’s (IHS) International Classification of Headache Disorders (ICHD-II codes 2.1, 2.2, and 2.3), the headache of the various subtypes of tension-type headache (TTH) is usually bilateral, of a pressing quality, of mild or moderate intensity, not aggravated by physical activity, and rarely accompanied by mild symptoms such as nausea, photophobia, or phonophobia. Although these characteristics are encountered in the vast majority of patients, it must be kept in mind, as demonstrated by a populationbased study (18), that 18% of patients may have a pulsating headache, 10% unilateral pain, 28% aggravation on routine physical activity, 18% anorexia, 4% nausea, and 11% photophobia (Table 79-1). Two problems arise, therefore, in diagnosing TTH. On the one hand, although it is the most frequent present in up to 78% in the population-based study by Rasmussen (20), it is also the least distinct of all headache types; its clinical diagnosis is based chiefly on negative features, that is, on the absence of symptoms that characterize other primary or secondary headaches (the absence of unilaterality, pulsatility, aggravation by physical activity, associated symptoms, and so on). On the other hand, a nonnegligible minority of patients may present with symptoms that are found in other headache types. The lack of specificity as well as the uncommon features may make the clinician, and thus the patient, hesitate about the correct diagnosis and explain why paraclinical investigations to exclude organic disease are (and probably should be) performed more frequently in tension-type headache than in other headaches (e.g., migraine). In particular, an atypical history or an abnormality on clinical examination indicates the need for further investigations, for example, for computed tomography (CT) or magnetic resonance imaging (MRI). Several studies confirm that brain imaging studies have a low likelihood of discovering significant intracranial disease in adult or pediatric patients with normal physical and neurologic exams, typical headache patterns, and no change in preexisting headache (7,18, 23,37).

Differential Diagnosis With Secondary Headaches

Many of the secondary headache types listed under the major headings of the IHS classification, however, may mimic TTH at some stage of their clinical course. Here we examine only the most frequent among them (Table 79-2). In clinical practice, the most frequent cause of chronic daily headache is medication-overuse headache (ICHD code 8.2), to which patients may evolve after having presented initially with migraine or with episodic tension-type headache or chronic tension-type headache (CTTH) (2,8,19,26). (For further details see Chapter 118.) Even if the initial disorder is migraine, with medication overuse, migraine attacks progressively become less characteristic and mixed with another headache type that phenotypically resembles tension-type headache (2,15). Recognizing this condition is of crucial importance because any kind of therapy for the initial headache type becomes effective only after the patient has been withdrawn from analgesic or specific antimigraine compounds.

Headache is usually the most prominent symptom of the so-called “posttraumatic syndrome” that may occur after minor or major injury to the head or neck (ICHD-II code 5) (see Chapters 105 and 106). In more than 80% of patients the headache resembles TTH. According to the ICHD-II of the IHS, any headache that develops within 7 days after a head or neck trauma can be considered to be posttraumatic. Acute posttraumatic headache (code 5.1) resolves within 3 months after the trauma, while the chronic type persists beyond this time point (code 5.2).

TABLE 79-1 Atypical Features of Tension-Type Headache and Their Incidence

*Feature*	*Percentage*
Aggravation by routine physical activity	28
Pulsating headache	18
Anorexia	18
Photophobia	11
Unilateral headache	10
Nausea	4
(From Maytal J, Bienkowski RS, Patel M, Eviatar L. The value of brain imaging in children with headaches. Pediatrics 1995;96:413-416, with permission.)

Usually there is little difficulty in distinguishing symptomatic headache caused by sinus or eye disease from TTH. Chronic sinusitis cannot be accepted as a cause of headache on the basis of a simple radiologic thickening of sinus mucosa. At least intermittent radiologic or clinical signs of ongoing sinus disease must be present. Similarly, radiologic evidence of cervical spondylosis is rarely a satisfactory explanation for a headache, because it can be found with equal prevalence in age-matched headache-free subjects (36).

The relation between oromandibular dysfunction and TTH remains controversial (see Chapter 73). Oromandibular dysfunction was listed in the first edition of the IHS classification as a possible causative factor at the fourth digit code level. The fourth digit coding has been omitted in the ICHD-II. Because of its high prevalence, however, the occurrence of oromandibular dysfunction with TTH in the same subject can be fortuitous. The similar prevalence of oromandibular dysfunction in subjects from the general population suffering from TTH or migraine or devoid of headache suggests that a causal relationship with TTH is rare (3,12).

Changes in intracranial pressure are well-known causes of headache (see Chapters 113 and 114). Whereas spontaneous or symptomatic intracranial hypotension is most often distinguishable from other headache types by its clear-cut accentuation when the patient is in the erect position (orthostatic headache), intracranial hypertension may produce a headache that can mimic migraine or TTH. Although brain tumors (see Chapter 116) represent only a small minority of the causes of headache, they obviously are a major concern to patients and clinicians. Headache occurs at presentation in approximately 36 to 50% of patients with brain tumors and develops in the course of the disease in 60% (31). Headaches are a more common symptom of brain tumor in children (i.e., in more than 90%). The headache is usually generalized like TTH, though in 30 to 80% of patients, it overlies the tumor. Headache awakening the patient from sleep or present on awakening and associated with vomiting is a frequent characteristic of brain tumor, which may also occur in some migraineurs but is not a feature of TTH.

TABLE 79-2 Secondary Headache Disorders That Sometimes Mimic Chronic Tension-Type Headache

Medication overuse headache	(ICHD-II 8.2)
Chronic posttraumatic headache	(ICHD-II 5.2)
Sinus/eye disease	(ICHD-II 11.3, 11.5)
Cervical spondylosis	(ICHD-II 11.2)
Temporomandibular joint disorder	(ICHD-II 11.7)
Idiopathic intracranial hypertension	(ICHD-II 7.1.1)
Brain tumor	(ICHD-II 7.4)
Psychiatric disorders	(ICHD-II 12)