Headache from the neck: can it spread to the face and teeth?

The international classification of headache disorders (ICHD-3) defines headache from the neck as headache caused by a problem with the neck vertebrae, the discs between them or the soft tissues of the neck, often accompanied by neck pain. The same classification notes that pain carried by the upper neck nerves and pain carried by the trigeminal nerve come together in the brainstem, and that this is now well understood. A review published in The Lancet Neurology also writes that laboratory and clinical studies have shown that pain from the upper neck joints and muscles can be referred to the head.

This convergence explains why the pain is felt far from its source. The brain cannot always tell whether a signal arriving at the same centre is coming from the neck or from the face. As a result, pain from a joint or muscle at the back of the neck can be felt in the forehead, around the eye, in the temple or in the cheek. This referral is not one-way: pain from the jaw joint and the chewing muscles can also spread to the neck, the temple and the ear. That is why the place where the pain is felt does not on its own show its source.

How common is it? In a population study in the Vågå area of Norway, in which 1838 people aged 18–65 were interviewed and examined, the prevalence of headache from the neck was 4.1 percent. In 97 percent of cases, the attacks of pain started at the back of the neck or the back of the head. Features typical of migraine, such as nausea, vomiting and throbbing, were rare. This study did not find it to be more common in women; a different direction from migraine and tension-type headache.

ICHD-3 lists the features that help to set this pain apart from migraine and tension-type headache as follows: the pain always staying on the same side, the typical pain being brought on by pressing on the neck muscles with a finger or by moving the head, and the pain spreading from back to front. The classification also states clearly that these features are not unique to headache from the neck and do not on their own prove cause and effect. For the diagnosis, there needs to be a problem in the neck that can cause pain, and evidence such as the pain starting and improving together with this problem, restricted neck movement or the pain going away with a numbing injection into the structure in the neck.

Neck findings on X-rays and MRI scans can mislead you. ICHD-3 writes that imaging findings in the upper neck vertebrae are also common in people without headache, so although they suggest a cause, they do not prove it. The Lancet Neurology review also states that the validity of the clinical diagnostic criteria has not been proven, and that showing for certain that the pain comes from the neck is only possible with controlled nerve-numbing injections done under X-ray guidance. In everyday practice, the diagnosis is usually made at the level of 'probable' and becomes clear from the response to treatment.

The link between the neck and the jaw has been measured. In a meta-analysis combining observational studies, there was moderate evidence that in people with a jaw joint and chewing muscle problem (temporomandibular disorder, TMD), loss of daily function related to the neck and loss of function related to the jaw were associated with each other, the pressure pain threshold in the neck was lower and the range of neck movement was more restricted. The same analysis found no significant difference in head and neck posture (such as a forward head posture). In other words, posture on its own is not to blame; these studies show an association, not which one causes the other.

Tender spots in the neck and jaw muscles can refer pain to the head and face. In a study comparing 20 women with jaw muscle pain and 20 women with widespread muscle pain (fibromyalgia), the muscle at the side of the neck (sternocleidomastoid), the muscles at the back of the neck and the trapezius were examined alongside the temple and jaw muscles; spots that brought on the patient's familiar pain when pressed (active trigger points) were found. In those with jaw muscle pain, this referred pain settled more in the mouth and face, and in fibromyalgia more in the neck. The study is small and does not measure pain referred to the teeth separately; there is no strong evidence for pain referred from the neck to the teeth.

Not every pain that comes with neck pain is a muscle or joint. MSD Manuals lists among the rare but serious causes of neck pain a tear in the inner wall of an artery in the neck (dissection), meningitis, a tumour or infection in the spine, and a heart attack and angina. It writes that dissection usually causes constant pain in the head, neck or face, often accompanied by neurological symptoms such as loss of balance, weakness in the arm and leg on the same side, or difficulty swallowing, speaking or seeing. That is why, in a picture where pain in the neck, face and head comes together, these signs are looked at first.

The first list is signs that make it more likely the pain is coming from the neck; the second list is signs that point to a tooth, the jaw joint or a cause that should not wait. The examination makes the distinction; these lists are so that you take the right information to the doctor.

MSD writes that with neck pain, doctors first try to rule out a serious illness. That is why the sequence starts with emergency signs and then moves on to telling the neck, the jaw and the teeth apart.

1. 1

   First, emergency signs

   If there is a very high temperature, a stiff neck or discomfort from light, a seizure, a head injury in the last 3 months, numbness or weakness in the face or arm, problems with speech, balance or vision, confusion, very severe pain that starts suddenly or pressure in the chest, the assessment is done in A&E; call 112.

2. 2

   The history of the pain

   You are asked where the pain starts, whether it is always on the same side, whether it changes with neck movement, posture or chewing, and whether you have had a neck injury in the past (for example, a neck injury in a road traffic accident). Noting down what starts the pain over a few days helps.

3. 3

   Neck and nerve examination

   MSD writes that the examination focuses on the spine and the nervous system, that muscle strength, reflexes and sensation are checked to look for a trapped nerve root or compression of the spinal cord, and that the doctor may ask you to move your neck in certain directions.

4. 4

   Jaw and tooth examination

   If there is also pain in the face or a tooth, the dentist examines the teeth with cold, tapping and bite tests and X-rays, and examines the jaw joint and chewing muscles by hand. If no tooth reproduces the pain, no procedure that cannot be reversed is done on a tooth.

5. 5

   Imaging if needed

   MSD writes that a neck MRI scan is requested when there are signs of a nerve root problem, such as pain spreading to the arm, numbness or weakness. According to ICHD-3, because imaging findings in the neck are also common in people without pain, they do not prove the cause on their own.

6. 6

   Steps that make the diagnosis clear

   If the pain continues and the diagnosis is uncertain, a pain specialist can do a test injection that numbs a particular joint or nerve in the neck under X-ray guidance. According to the Lancet Neurology review, these controlled nerve blocks are the way to show for certain that the pain is coming from the neck.

Treating headache from the neck is not the dentist's field, but that of GPs, physiotherapy, neurology and pain specialists. If a jaw joint and chewing muscle problem comes with it, the dentist deals with that part separately.

Most of the mistakes come from looking at where the pain is and searching for its source there.

Times vary from person to person. The sequence below is a general framework; the plan of the doctor who follows you up comes first.

1. The first days

   The NHS writes that most neck pain lasts a few weeks. During this period, keeping the neck moving, applying heat or cold and painkillers help.

2. After a few weeks

   If neck pain or stiffness has not gone away in a few weeks, or painkillers have not worked, the NHS recommends seeing your GP. Physiotherapy and an exercise programme start at this stage.

3. The exercise programme

   In the Australian study, treatment lasted 6 weeks and its effect was maintained for 12 months. Keeping up the exercises regularly is important.

4. If it continues

   With headache that keeps coming back regularly and does not respond to treatment, you are referred to a neurologist or a pain specialist; if facial and jaw pain also continues, the dentist reassesses the jaw joint and the muscles.

We do not give a single figure here, because treating pain from the neck is not the dentist's field but that of physiotherapy, neurology and pain specialists, and its scope varies from person to person. These are the items that determine the scope:

When the diagnosis is made

When referred pain is recognised early, unnecessary procedures that might be done on the teeth are avoided.

Whether imaging is needed

In typical cases with no signs of a nerve root problem, imaging is usually not the first step; a neck MRI scan is requested depending on the findings.

Number of physiotherapy sessions

The length of the exercise and manual therapy programme varies with the course of the pain.

An accompanying jaw problem

If there is also a jaw joint or chewing muscle problem, a dental examination and, if needed, a night guard are a separate item.