Tension-type headache (TTH) is the most common type of primary headache. It is characterised by a dull, band-like pain across the forehead and has no autonomic features (such as photophobia and phonophobia). It occurs most commonly between 20-30 years of age and is more common in females.
Pathophysiology
The pathophysiology of TTH is not fully understood but known to be multifactorial. It is thought that in TTH, peripheral factors are involved (in contrast to the central factors involved in migraine pathophysiology).
- Muscular tension and nociception:
- Peripheral activation or sensitisation of nociceptors located in the muscles and fascia of the head and neck are most likely of involved in episodic TTH, while sensitisation of pain pathways in the CNS due to prolonged nociceptive stimuli from tissues around the head and neck seem to be responsible for the conversion of episodic → chronic TTH.
- CNS involvement:
- Central sensitisation & altered pain processing as mentioned above.
- Neurotransmitter imbalance:
- Changes in serotonin levels may contribute to TTH.
- Psychological factors:
- Psychological factors, such as stress and anxiety, are commonly associated with TTH. Emotional stress can lead to muscle tension and trigger headache episodes through the mechanisms mentioned previously.
- Genetic factors:
- Individuals with a family history of TTH may be more likely to experience TTH. These genetic factors are more likely to influence the development of chronic TTH.
- Triggers:
- Certain environmental factors, such as bright lights, loud noises, and prolonged screen time, may act as triggers for TTH in susceptible individuals. These triggers influence the development of episodic TTH.
🔢 Classification
The ICHD classifies TTH as follows based on the frequency of attacks:
- Infrequent episodic TTH - <1 day of headache monthly.
- Frequent episodic TTH - ≥10 episodes of headaches on less than 15 days per month on average for more than 3 months.
- Chronic TTH - ≥15 days or more of headaches per month for more than 3 months (and no medication overuse present).
⚠️ Risk factors
- Pericranial muscle tenderness
- Stress
- Caffeine
- Disturbed sleep
- Infrequent meals
- Female sex
- Medication overuse
😷 Presentation
- Generalised headache - by generalised we mean bilateral. It may feel like a band-like compression around the forehead that is mild-moderate in intensity and is non-pulsatile.
- Episodic nature - as mentioned above in the classification. Headaches may last from 30 minutes to a couple of days.
- Not associated with nausea and vomiting.
- Not aggravated by normal physical activity.
- Frontal or occipital pain - the headache is most commonly in these two regions.
- Photophobia or phonophobia - only one of the two will be present.
- Pericranial tenderness - this includes muscles such as the sternocleidomastoid, trapezius, temporalis, lateral pterygoid, masseter.
🔍 Investigations
⭐️ The diagnosis of TTH is a clinical diagnosis.
- History and physical examination should be undertaken. TTH has a normal neurological examination. It is also wise to assess the blood pressure of the patient.
- Headache diaries can be used to aid diagnosis and guide clinical decision-making.
- Imaging - such as CT or MRI may be considered in cases of refractory or worsening headaches.
🧰 Management
We will discuss the management of an acute attack of TTH followed by the management of chronic TTH:
- 🥇 Analgesia - simple analgesia is recommended such as paracetamol or NSAIDs. Patients should be advised to take them as soon as possible after the attack onset. Patients should also be advised to avoid opioids.
- Assess for triggers - this may be stress, posture, diet, improper sleep etc.
Patients who suffer from frequent or chronic TTHs should be advised on avoiding frequent analgesics as this may precipitate medication overuse headache (we will discuss this below).
Options for management include:
- Acupuncture - a course of 6-10 sessions may prove useful and may be prescribed depending on referral pathways.
- Physiotherapy and/or regular exercise
- CBT and/or relaxation techniques
- Amitryptaline - it can be used prophylactically instead of acute treatment for attacks. It may be trialled for 2-3 months. If the response is good then it can be continued for at least 6 months before gradually reducing the dose and eventually stopping it. A headache calendar can also be implemented to monitor adherence and also to monitor the response to the drug treatment.
🚨 Complications
MOH is a secondary headache disorder that is attributable to the rebound effect that comes with chronic medication use (often due to treating primary headaches such as migraine or TTH).
It is defined as a a headache occurring on ≥15 days per month in an individual with a primary headache disorder. It develops as a result of regular medication use for acute treatment of headaches for >3 months. Most often (but not always) it resolves after overuse is stopped.
It occurs if:
- Simple analgesics (NSAIDs and paracetamol) are taken on ≥15 days per month.
- Ergotamines, triptans or opioids are taken on ≥10 days per month.
Patients should be advised to stop taking the overused medication for at least 1 month. There may be an initial rebound worsening and withdrawal symptoms such as nausea and vomiting, reduced appetite, hypotension, tachycardia, sleep disturbances, anxiety. However, the headache should improve after 1-2 weeks (but may only fully improve up to 3 months later).