Headache

Headache is defined as the symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders.

Classification

Headache type is not stable over time.

Primary headaches

Primary headaches are defined as "conditions in which the primary symptom is headache and the headache cannot be attributed to any known causes."

Migraine headache

Criteria

Diagnostic criteria developed by the International Headache Society are:
Migraine without aura:
A. At least 5 attacks fulfilling criteria B-D
B. Headache attacks lasting 4-72 hours (untreated or unsuccessfully treated)
C. 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 (eg, walking or climbing stairs)

D. During headache at least one of the following:

1. nausea and/or vomiting
2. photophobia and phonophobia

E. Not attributed to another disorder

Cluster headache

Criteria

Diagnostic criteria developed by the International Headache Society are:
A. At least 5 attacks fulfilling criteria B-D
B. Severe or very severe unilateral orbital, supraorbital and/or temporal pain lasting 15-180 minutes if untreated1
C. Headache is accompanied by at least one of the following:

1. ipsilateral conjunctival injection and/or lacrimation
2. ipsilateral nasal congestion and/or rhinorrhoea
3. ipsilateral eyelid oedema
4. ipsilateral forehead and facial sweating
5. ipsilateral miosis and/or ptosis
6. a sense of restlessness or agitation

D. Attacks have a frequency from one every other day to 8 per day
E. Not attributed to another disorder

Secondary headache

Secondary headaches are defined as "conditions with headache symptom that can be attributed to a variety of causes including brain vascular disorders; wounds and injuries; infection; drug use or its withdrawal."

Medication-overuse headache

Medication-overuse headache has also been called rebound headache, drug-induced headache, medication-misuse headache. According to the International Classification of Headache Disorders, 2nd Edition (ICHD-II)—-Revision of Criteria for 8.2 Medication-Overuse Headache, criteria are:

• "Headache present on ≥15 days/month."
• "Regular overuse for >3 months of one or more drugs that can be taken for acute and/or symptomatic treatment of headache."
  • "Simple analgesics on >15 days/month on a regular basis for >3 months."
  • "Ergotamine, triptans, opioids or combination analgesics on >10 days/month on a regular basis for >3 months."
  • "Any combination of ergotamine, triptans, analgesics and/or opioids >15 days/month on a regular basis for >3 months without overuse of any single class alone."

• Headache has developed or markedly worsened during medication overuse.

The role of overuse of medications for treating migraine (triptans, analgesics, ergots) and their withdrawal as a cause of headache has been successfully and unsuccessfully demonstrated in trials.

Medication-overuse headache is suggested if the sum of the answers to the following Severity of Dependence Scale are ≥5 for women and ≥4 for men:

1. "Do you think your use of headache medication was out of control? (never/almost never=0, sometimes=1, often=2, always/nearly always=3)"
2. "Did the prospect of missing a dose make you anxious or worried? (never/almost never=0, sometimes=1, often=2, always/nearly always=3)"
3. "Did you worry about your use of your headache medication? (never/almost never=0, sometimes=1, often=2, always/nearly always=3)"
4. "Did you wish you could stop? (never/almost never=0, sometimes=1, often=2, always/nearly always=3)"
5. "How difficult would you find it to stop or go without your headache medication? (not difficult=0, quite difficult=1, very difficult=2, impossible=3"

Diagnosis

X-ray computed tomography (CT Scan) should be considered if one of the following is present:

• cluster-type headache
• abnormal findings on neurologic examination
• undefined headache (ie, not cluster, migraine, or tension-type)
• headache with aura
• headache aggravated by exertion or a valsalva-like maneuver
• headache with vomiting

Possible subarchnoid hemorrhage: nontraumatic headache that peaked within 1 hour and:

• age ≥40, neck pain or stiffness
• limited neck flexion
• witnessed loss of consciousness
• onset during exertion
• thunderclap headache (instantly peaking pain)

CT scan should also be considered in the following settings:

• Acute thunderclap headache. Prevalence of significant pathology is 40%
• New-onset or change in chronic headaches. Prevalence of significant pathology is 32%. This compares to a prevalence of significant pathology of 1% for patients with chronic headaches referred to a neurologist. Presumably the prevalence would be lower in primary care.
• Patients with human immunodeficiency virus. This is based on a clinical practice guideline.

Treatment

Prochlorperazine is better than promethazine in relieving nonspecific, benign headaches according to a randomized controlled trial.

After relief has been achieved, recurrence may be similarly affected by oral sumatriptan and oral naproxen.

Medication-overuse headache

A trial found the following counseling that lasted about 9 minutes to be effective:

• Patients are given information about medication-overuse headache
• "Patients received feedback on their SDS score and risk of medication-induced headache. "
• "With a consultation in an empathic and collaborative manner, the BI aimed towards achieving a decision by the patient that he/she would cut down the offending medication, an agreement about how the GP could support and a concrete plan. "
• "Explicit recommendations were reduction in headache medication towards ‘safe levels’, and information about possible difficulties and gains including that MOH usually ‘gets worse before it improves’ 1–2 weeks after withdrawal."

Prognosis

Most chronic headaches are tension-type headache, although migraine may coexist. Almost half have medication overuse.