Tension headache

Tension headache
A woman experiencing a tension headache
Classification and external resources
Specialty	Neurology
ICD-10	G44.2
ICD-9-CM	307.81, 339.1
DiseasesDB	12554
MedlinePlus	000797
eMedicine	article/1142908
Patient UK	Tension headache
MeSH	D018781

Tension headache, also known as tension-type headache, is the most common type of primary headache. The pain can radiate from the lower back of the head, the neck, eyes, or other muscle groups in the body typically affecting both sides of the head. Tension-type headaches account for nearly 90% of all headaches.

Tricyclic antidepressants appear to be useful for prevention. Evidence is poor for SSRIs, propranolol and muscle relaxants. For the treatment of a tension headache, ibuprofen is effective.

Tension headaches affect about 1.4 billion people (20.8% of the population) and are more common in women than men (23% to 18% respectively).

Signs and symptoms

Tension-type headache pain is often described as a constant pressure, as if the head were being squeezed in a vise. The pain is frequently present on both sides of the head at the same time. Tension-type headache pain is typically mild to moderate, but may be severe.

Frequency and duration

Tension-type headaches can be episodic or chronic. Episodic tension-type headaches are defined as tension-type headaches occurring fewer than 15 days a month, whereas chronic tension headaches occur 15 days or more a month for at least 6 months. Tension-type headaches can last from minutes to days, months or even years, though a typical tension headache lasts 4–6 hours.

Cause

Various precipitating factors may cause tension-type headaches in susceptible individuals:

• Stress: usually occurs in the afternoon after long stressful work hours or after an exam
• Sleep deprivation
• Uncomfortable stressful position and/or bad posture
• Irregular meal time (hunger)
• Eyestrain

One half of patients with tension-type headaches identify stress or hunger as a precipitating factor.

Tension-type headaches may be caused by muscle tension around the head and neck. One of the theories says that the main cause for tension-type headaches and migraine is teeth clenching which causes a chronic contraction of the temporalis muscle.

Another theory is that the pain may be caused by a malfunctioning pain filter which is located in the brain stem. The view is that the brain misinterprets information—for example from the temporal muscle or other muscles—and interprets this signal as pain. One of the main neurotransmitters that is probably involved is serotonin. Evidence for this theory comes from the fact that chronic tension-type headaches may be successfully treated with certain antidepressants such as amitriptyline. However, the analgesic effect of amitriptyline in chronic tension-type headache is not solely due to serotonin reuptake inhibition, and likely other mechanisms are involved. Recent studies of nitric oxide (NO) mechanisms suggest that NO may play a key role in the pathophysiology of CTTH. The sensitization of pain pathways may be caused by or associated with activation of nitric oxide synthase (NOS) and the generation of NO. Patients with chronic tension-type headache have increased muscle and skin pain sensitivity, demonstrated by low mechanical, thermal and electrical pain thresholds. Hyperexcitability of central nociceptive neurons (in trigeminal spinal nucleus, thalamus, and cerebral cortex) is believed to be involved in the pathophysiology of chronic tension-type headache. Recent evidence for generalized increased pain sensitivity or hyperalgesia in CTTH strongly suggests that pain processing in the central nervous system is abnormal in this primary headache disorder. Moreover, a dysfunction in pain inhibitory systems may also play a role in the pathophysiology of chronic tension-type headache.

Prevention

Tricyclic antidepressants have been found to be more effective than SSRIs but have greater side effects. Evidence is insufficient for the use of SSRIs, propranolol and muscle relaxants for prevention of tension headaches.

The first-line treatment for chronic tension type headache is amitriptyline, whereas mirtazapine and venlafaxine are second-line treatment options. Biofeedback techniques may also help.

Treatment

Medications

Episodic tension-type headaches generally respond well to over-the-counter analgesics such as ibuprofen, paracetamol/acetaminophen, and aspirin. Analgesic/sedative combinations are widely used (e.g., analgesic/antihistamine combinations like Syndol, Mersyndol and Percogesic, analgesic/barbiturate combinations such as Fiorinal). Frequent use of analgesics may, however, lead to medication overuse headache.

Botulinum toxin is a treatment trialled by some people with tension-type headache, though results are varied.

Acupuncture

Though evidence for acupuncture is slight, some suggest it may be useful in those with frequent or chronic tension headaches.

Manual therapy

People with tension-type headache often use spinal manipulation, soft tissue therapy, and myofascial trigger point treatment. Studies of effectiveness are mixed. A 2006 systematic review found no rigorous evidence supporting manual therapies for tension headache. A 2005 structured review found only weak evidence for the effectiveness of chiropractic manipulation for tension headache, and that it was probably more effective for tension headache than for migraine. A 2004 Cochrane review found that spinal manipulation may be effective for migraine and tension headache, and that spinal manipulation and neck exercises may be effective for cervicogenic headache. Two other systematic reviews published between 2000 and May 2005 did not find conclusive evidence in favor of spinal manipulation. A 2012 systematic review of manual therapy found that hands-on work may reduce both the frequency and the intensity of chronic tension-type headaches.

Epidemiology

Tension headaches affect about 1.4 billion people (20.8% of the population) and are more common in women than men (23% to 18% respectively). Despite its benign character, tension-type headache, especially in its chronic form, can impart significant disability on patients as well as burden on society at large.

Prognosis

Tension headaches that do not occur as a symptom of another condition may be painful, but are not harmful. It is usually possible to receive relief through treatment. Tension headaches that occur as a symptom of another condition are usually relieved when the underlying condition is treated. Frequent use of pain medications in patients with tension-type headache may lead to the development of medication overuse headache or rebound headache.

External links

• American Council for Headache Education
• National Headache Foundation
• World Headache Alliance