Definition and Prevalence

Chronic daily headache is diagnosed based on the presence of headaches occurring for 15 or more days per month, over a period of three consecutive months, without any underlying organic pathology. These headaches last for more than 4 hours per day. This disorder predominantly affects adolescents and adults but can also occur before puberty. It affects up to 4% of young women and up to 2% of young men, with similar prevalence rates reported in studies from Asia, Europe, and the United States (Kavuk et al., 2003).

Classification

Silberstein et al. (1996) defined four categories of chronic daily headache based on symptoms:

1. Transformed or chronic migraine
2. Chronic tension-type headache
3. New daily persistent headache
4. Hemicrania continua

Many adolescents with chronic daily headache have a history of episodic migraine, which may transform into chronic migraine gradually over weeks to months or abruptly within hours (Mack, 2004). Approximately a quarter of adolescents with chronic daily headache have no significant past headache history, with new daily persistent headache often triggered by an infection like mononucleosis or a minor head injury (Mack, 2004).

Symptomatology

Patients with chronic daily headache typically experience at least two types of headaches:

1. Severe Intermittent Headaches: These are migrainelike, often described as throbbing, severe, crushing, knife-like, or hatchet-like, and are usually pancephalic or frontal in location. Associated symptoms include nausea, photophobia, phonophobia, and osmophobia. Sleep may help alleviate pain, but headaches often persist upon awakening. These severe headaches occur multiple times a week.
2. Continuous Headache: Present 24/7, this headache waxes and wanes in severity, often worsening in the morning or at the end of the school day. The pain is similar to that of severe headaches but less intense, and may also have features of a tension-type headache, described as band-like or crushing.

Associated Symptoms

Chronic daily headache is a multi-symptom complex. Common associated symptoms include:

• Sleep Disruption: Affects two-thirds of patients, and headaches often do not resolve until sleep improves (Dodick et al., 2003).
• Dizziness: Often positional and associated with weakness, unsteadiness, and blurry or lost vision, without vertigo except during severe headaches. Positional changes may lead to syncope or near-syncope. Symptoms are particularly prominent in the morning and can be linked to postural orthostatic tachycardia syndrome (POTS) or a decrease in systolic blood pressure upon standing (Raskin and Knittle, 1976; Johnson et al., 2010).
• Mood Problems and Anxiety: These may precede or follow the onset of headaches. Effective management of both mood and headache symptoms is crucial.
• Other Pain Symptoms: Non-specific abdominal pain, back pain, neck pain, and diffuse muscle and joint pain, often without additional organic causes.
• Environmental Factors: Seasonal variability with improvement in summertime and worsening at the start of the school year, leading to significant school absence (Sartory et al., 1998).

Treatment and Management

In addition to preventive treatments for migraine, other therapies for chronic migraine include:

• Onabotulinumtoxin Type A: Shown to be effective in reducing headache levels and migraine days in adults, with retrospective studies indicating similar effectiveness in adolescents (Ahmed et al., 2010).
• Cefaly Antimigraine Device: A neurostimulatory device used on the forehead for 20 minutes daily to decrease headache burden, particularly effective for patients without allodynia (Schoenen et al., 2013).
• Trigger Point Injections: Useful in decreasing pain for patients with chronic post-traumatic headaches or neuralgia.

Future Treatments

The next generation of medications for migraine and chronic migraine will target CGRP, a neurotransmitter associated with pain. Several pharmaceutical companies are developing these treatments, which hold potential for both abortive and preventive use (Schuster and Rapoport, 2016).

Treatment Approach

Chronic daily headache (CDH) is challenging to manage, often requiring weeks to months for noticeable improvement. The key components of therapy include education, preventive medications, and managing environmental triggers.

Education and Expectations

Patients and families should be educated on several points:

• The chronic nature of the condition.
• The absence of abnormalities in diagnostic tests.
• The delayed efficacy of prescribed medications.
• The role of non-medication approaches such as biofeedback or physical therapy.

Setting Realistic Expectations:

• Short-Term Goals: After one month of effective therapy, patients can expect less frequent severe headache episodes and a decrease in the intensity of the continuous headache.
• Long-Term Goals: Complete resolution of headaches in a short period is rare. Improvement trends guide medication dosage adjustments, and preventive treatments should continue for at least six months.

Preventive Medications

Preventive medications aim to reduce the frequency and severity of headaches. In CDH, the goal is to make severe intermittent headaches less frequent and the continuous headache less intense.

Common Preventive Medications:

• Tricyclic Antidepressants: Amitriptyline is commonly used but requires monitoring for ECG changes due to QT interval prolongation. It can cause weight gain, which is a concern for adolescents, and it may help with sleep onset. Nortriptyline or protriptyline may cause less sedation (Hershey et al., 2000).
• Selective Serotonin Reuptake Inhibitors (SSRIs): Effective in some adults for chronic headache, they are less effective than tricyclics for pain control but beneficial for mood improvement in children (Saper et al., 1994).
• Anticonvulsants: Valproate, topiramate, and gabapentin have shown usefulness. These medications can be chosen based on the patient's other conditions, such as mood disorders or sleep problems.

Specific Medications for Conditions:

• Beta-Blockers: Can be useful for postural orthostatic tachycardia syndrome but may worsen depression.
• Calcium Channel Blockers: Useful for patients with hypertension but can cause constipation and orthostatic hypotension.
• Topiramate: A good choice for patients needing weight loss, though it may cause cognitive clouding.
• Botulinum Toxin: Shows promise in reducing headache frequency and severity (Mack and Gladstein, 2008).

Pain Management During Headaches

Managing pain during headaches is difficult. Analgesics effective for episodic migraines are often ineffective for CDH. Overuse of analgesics can lead to rebound headaches, so patients should avoid using them for continuous headaches. However, for severe intermittent migraine-like headaches, medications such as triptans, indomethacin, or NSAIDs can be considered.

Non-Pharmacological Approaches

Non-pharmacological treatments are crucial in managing CDH. These include:

• Relaxation Therapy and Biofeedback: Can be introduced through consultations with psychologists.
• Reconditioning Exercise Program: Patients should start with 10 minutes of aerobic exercise daily, gradually increasing by 10% per week.

Prognosis

Data on the duration and outcome of CDH in children are limited. However, it is not unusual for children to experience chronic daily headaches for months to years. Effective management and preventive treatments can significantly improve the quality of life, though complete resolution may be rare in the short term.

Hemicrania Continua

Hemicrania continua is a rare headache disorder, affecting approximately one percent of chronic daily headache sufferers. This condition is characterized by persistent unilateral headache pain, which can include stabbing sensations and may be accompanied by autonomic changes. Recognizing hemicrania continua is crucial, as patients often respond well to daily doses of indomethacin.