Tension Headache

Tension-type headache (TTH), also known as tension headache or stress headache, is the most common type of primary headache. The pain typically radiates from the lower back of the head, the neck, and the eyes, often affecting both sides of the head. Tension-type headaches account for nearly 90% of all headaches.

Signs and Symptoms

According to the third edition of the International Classification of Headache Disorders, TTH attacks must meet specific criteria:

• A duration of between 30 minutes and 7 days.
• At least two of the following characteristics: bilateral location, pressing or tightening (non-pulsating) quality, mild or moderate intensity, not aggravated by routine physical activity such as walking or climbing stairs.
• Both of the following: no nausea or vomiting, no more than one of photophobia (sensitivity to bright light) or phonophobia (sensitivity to loud sounds).

Tension-type headaches may be accompanied by tenderness of the scalp on manual pressure during an attack.

Risk Factors

Various precipitating factors may cause tension-type headaches in susceptible individuals, including anxiety, stress, sleep problems, a young age, and poor health.

Mechanism

Although the musculature of the head and neck and psychological factors such as stress may play a role in the pathophysiology of TTH, neither is currently believed to be the sole cause. The pathologic basis of TTH is most likely derived from a combination of personal factors, environmental factors, and alterations in both peripheral and central pain pathways.

Peripheral pain pathways receive pain signals from pericranial myofascial tissue. Alterations in these pathways may underlie episodic tension-type headache (ETTH). Prolonged alterations can lead to increased excitability of the central nervous system pain pathways, resulting in chronic tension-type headache (CTTH). Hyperexcitability occurs in central nociceptive neurons, leading to central sensitisation and is expressed as allodynia and hyperalgesia in CTTH.

Neurotransmitters

Specific neuronal receptors and neurotransmitters thought to be involved include NMDA and AMPA receptors, glutamate, serotonin (5-HT), β-endorphin, and nitric oxide (NO). NO plays a major role in central pain pathways and likely contributes to central sensitisation.

Synapses

Homosynaptic and heterosynaptic facilitation are both likely to be involved in central sensitisation. Homosynaptic facilitation involves changes in synapses normally part of pain pathways, while heterosynaptic facilitation involves synapses not normally involved in pain pathways, leading to innocuous signals being interpreted as pain.

Stress

Stress may be implicated via the adrenal axis, resulting in downstream activation of NMDA receptors, NFκB activation, and upregulation of iNOS with subsequent production of NO leading to pain.

Diagnosis

With TTH, the physical exam is expected to be normal, except for potential pericranial tenderness or the presence of photophobia or phonophobia.

Classification

The International Headache Society classifies TTH into episodic (ETTH) and chronic (CTTH). CTTH is defined as having headaches for fifteen or more days per month for more than three months. ETTH is further divided into frequent and infrequent TTH based on the number of headache episodes.

Differential Diagnosis

Extensive testing is not typically needed as TTH is diagnosed by history and physical examination. However, if symptoms indicative of a more serious diagnosis are present, a contrast-enhanced MRI may be used. Conditions to consider in differential diagnosis include migraine, oromandibular dysfunction, sinus disease, eye disease, cervical spine disease, infection in immunocompromised individuals, intracranial mass, idiopathic intracranial hypertension, medication overuse headache, secondary headache, giant cell arteritis (for those ≥50 years of age), and dermatochalasis.

Prevention

Lifestyle

Good posture, avoiding alcohol, staying hydrated, treating jaw clenching, stress management, and biofeedback techniques may help in preventing tension headaches.

Medications

For those experiencing 15 or more headaches per month, daily antidepressants such as amitriptyline, mirtazapine, and venlafaxine may be used. Tricyclic antidepressants appear to be useful for prevention, but SSRIs, propranolol, and muscle relaxants have poor evidence for efficacy.

Treatment

Exercise

Neck and shoulder exercises, including stretching, strengthening, and range of motion exercises, are beneficial in managing ETTH and CTTH. Combined therapy with stress management, exercises, and postural correction is also effective.

Medications

Episodic

Over-the-counter drugs like paracetamol or NSAIDs (ibuprofen, aspirin, naproxen) can be effective for occasional use. Analgesic/caffeine combinations are also popular. Frequent use of these medications may lead to medication overuse headache.

Chronic

Medications for CTTH include tricyclic antidepressants, SSRIs, benzodiazepines, and muscle relaxants. Amitriptyline is commonly used due to its role in decreasing central sensitisation. These medications are ineffective if concurrent overuse of over-the-counter medications or other analgesics is occurring.

Manual Therapy

Current evidence for acupuncture is slight, though it may be beneficial for those with frequent tension headaches. Spinal manipulation, soft tissue therapy, and myofascial trigger point treatment have mixed evidence for effectiveness. Massage and physiotherapy may provide benefits for CTTH patients.

Epidemiology

As of 2016, tension headaches affect about 1.89 billion people and are more common in women than men (23% to 18% respectively). Despite their benign nature, tension-type headaches, especially in their chronic form, can impart significant disability on patients and burden society at large.

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Self-assessment MCQs (single best answer)

What is the most common type of primary headache?

Tension-type headache pain typically affects:

Which of the following is NOT a criterion for diagnosing TTH according to the International Classification of Headache Disorders?

What is a common symptom that may accompany tension-type headaches?

Which neurotransmitter is thought to play a major role in central pain pathways and contribute to central sensitisation in TTH?

Chronic tension-type headache (CTTH) is defined as having headaches for how many days per month for more than three months?

Which medication is commonly used to prevent tension-type headaches in individuals experiencing 15 or more headaches per month?

What type of exercise is beneficial for managing both episodic and chronic tension-type headaches?

Which of the following is NOT recommended for frequent use due to the risk of medication overuse headache?

As of 2016, what percentage of women are affected by tension-type headaches?