CHAPTER 32: Chronic Daily Headache

INTRODUCTION

Chronic daily headache relates to the daily or almost-daily occurrence of headache for a prolonged period of time. However, not all daily or almost-daily headaches fall under this denominator, as is the case with the daily or almost-daily headaches of (chronic) cluster headache and (chronic) paroxysmal hemicrania. These conditions can be referred to as paroxysmal daily headaches in which the headaches occur in well-defined attack patterns. In cluster headache, the attack pattern is that of headaches occurring once or twice a day and lasting 1 to 2 hours, whereas in paroxysmal hemicrania, it is that of headaches occurring 5 to 15 times per day and lasting 10 to 30 minutes.

Of the nonparoxysmal daily headaches, hemicrania continua is a condition that does not fall under the denominator of chronic daily headache, either. However, it is discussed in this chapter because it is very difficult, if not impossible, to distinguish from chronic daily headache on the basis of presentation alone. It differs from chronic daily headache in having a somewhat more consistent and less variable intensity of the pain and in an absolute response to preventive treatment with indomethacin.

In The International Classification of Headache Disorders, 2nd edition,¹ hemicrania continua is described under 4.7 as a persistent, strictly unilateral headache responsive to indomethacin. The diagnostic criteria are:

1. Headache for more than 3 months fulfilling criteria B through D.

2. All of the following characteristics:

   1. Unilateral pain without side-shift.

   2. Daily and continuous, without pain-free periods.

   3. Moderate intensity but with exacerbations of severe pain.

3. At least one of the following autonomic features occurs during exacerbations and ipsilateral to the side of pain:

   1. Conjunctival injection and/or lacrimation.

   2. Nasal congestion and/or rhinorrhea.

   3. Ptosis and/or miosis.

4. Complete response to therapeutic doses of indomethacin.

5. Not attributed to another disorder.

In terms of the diagnoses listed in The International Classification of Headache Disorders, chronic daily headache comprises the following three: chronic migraine (1.5.1), chronic tension-type headache (2.3), and new daily-persistent headache (4.8).

Chronic migraine is described as migraine headache occurring on 15 or more days per month for more than 3 months in the absence of medication overuse. The diagnostic criteria are:

1. Headache fulfilling criteria C and D for 1.1 Migraine without aura on 15 or more days per month for more than 3 months.

2. Not attributed to another disorder.

The criteria C and D for 1.1 Migraine without aura are as follows:

1. Headache has at least two of the following characteristics:

   1. Unilateral location.

   2. Pulsating quality.

   3. Moderate or severe pain intensity.

   4. Aggravation by or causing avoidance of routine physical activity.

2. During the headache, at least one of the following:

   1. Nausea and/or vomiting.

   2. Photophobia and phonophobia.

In 2006, the Headache Classification Subcommittee² changed the diagnostic criteria for chronic migraine as follows to be more inclusive:

1. Headache ...