35 Headache and Facial Pain
The head and neck region is a complex area anatomically, and this no less applies to its sensory innervation. Pain in the head and neck region is common. While no formal figures exist to substantiate this, personal experience, clinical anecdote and exposure will leave the reader in no doubt of the validity of this statement. A useful definition of pain was issued in 1986 by the International Association for the Study of Pain, and survives unchanged to date:
An unpleasant sensory and emotional experience associated with actual or potential tissue damage or expressed in terms of such damage.
Most patients will initially manage their pain with simple analgesia, and relevant medicines, based on their self-diagnosis, in the hope that it will settle quickly. If this does not happen, then they may become concerned that the pain is a consequence of some damaging physical process, whether that be infection, inflammation or tumour. At this point, they are likely to seek medical advice, usually from their GP, and if they find no resolution there, specialist referral usually follows. There is often clinical enthusiasm to attribute head and neck pain to some form of organic process without sufficient interrogation. These patients present to numerous specialists, undergo multiple investigations and sometimes unsuccessful surgical procedures before finally receiving appropriate diagnosis and treatment. It is unsurprising that many patients have had symptoms for years and have become disillusioned with the medical profession. Their symptoms are compounded by the inevitable emotional and psychological component that goes with chronic pain. If symptoms have been present for some time, successful pain management will not be achieved without acknowledgement of this fact.
Headaches and facial pain not only pose a frequent clinical scenario and diagnostic dilemma, but a problem in managing patients’ perceptions and expectations. As facial pain is a common manifestation of head and neck pain, sinonasal symptoms, whether from simple upper respiratory tract infections (URTIs) or rhinitis are also very common, the two regularly become connected in the patient’s mind (and often that of their GP!) and the patient presents with ‘sinus pain’. The ENT surgeon is then asked to address the patient’s ‘sinusitis’. With this in mind, it is clearly beneficial for the ENT surgeon to have some general knowledge of the causes, features and treatment of headaches and facial pain.
35.2 Clinical Assessment
If facial pain is to be successfully managed, it is essential to spend sufficient time with the patient to elicit a full history. There should be an emphasis on duration of both the problem and the episodes, triggers and associated symptoms. When taking a pain history, the patient will frequently find it difficult to convey the experience of the pain. The patient should be encouraged to use descriptive terms, such as burning, cramping, throbbing, stabbing which are of more value in suggesting diagnosis than words that indicate intensity, for example, sore, agonising, excruciating.
A full ENT examination should be performed and should include nasal endoscopy. It is preferable to try and avoid unnecessary investigations but, in these patients, scanning may be required to demonstrate the absence of underlying organic pathology.
Pain assessment tools have been developed which may aid the clinician in accurately defining the pain. The McGill Pain Questionnaire attempts to define the qualitative aspects of pain, while the Visual Analogue Scale is the most widely used pain intensity measure.
35.3 Headaches Classification
The International Headache Society has recently (August 2016—ichd-3.org) updated its classification (endorsed by the World Health Organisation) of headaches into three broad groups:
1. Primary headaches.
2. Secondary headaches.
3. Painful cranial neuropathies (neuralgias and facial pain).
35.3.1 Primary Headaches
• Migraine. There are 7 groups, of which migraine with aura and migraine without aura are the commonest and 20 subgroups.
• Trigeminal autonomic cephalalgias. These include cluster headache and paroxysmal hemicrania.
• Other primary headaches. These include primary stabbing headache, primary cough headache, primary exertional headache, primary headache associated with sexual activity, hypnic headache, primary thunderclap headache, hemicrania continua and new daily persistent headache.
35.3.2 Secondary Headaches
• Trauma or injury to the head and/or neck. These include acute or chronic post-traumatic headache attributed to mild, moderate or severe head injury; acute and chronic headache from whiplash; headache from epidural and subdural haematoma; acute and chronic post-craniotomy headache.
• Cranial or cervical vascular disorder. These disorders include ischaemic stroke and transient ischaemic attack; intra-cerebral or sub-arachnoid haemorrhage; unruptured vascular malformations such as arteriovenous malformation cavernous angioma, dural arteriovenous fistula; headache from arteritis such as giant cell arteritis; carotid or vertebral artery pain such as from arterial dissection, post-endarterectomy, post-angiography and post-angioplasty.
• Non-vascular intra-vascular disorders. These disorders include high intra-cranial pressure from hydrocephalus or idiopathic intra-cranial hypertension, low intra-cranial pressure from a lumbar puncture or idiopathic headache from non-infectious inflammatory disease such as neurosarcoidosis or aseptic meningitis, from an intra-cranial neoplasm (can cause raised intra-cranial pressure, carcinomatous meningitis, lymphocytic hypophysitis or primarily from the tumour itself), from an intra-thecal injection, from an epileptic seizure, from Chiari malformation type 1.
• Substance abuse or its withdrawal. Substances include alcohol, cocaine, cannabis, medication such as analgesia overuse, opioid overuse, trip-tan overuse. Withdrawal from caffeine, opiates and estrogen may cause headaches.
• Infection. This includes intra-cranial infection such as meningitis, encephalitis, brain abscess and subdural empyema; systemic infection including bacterial and viral and retroviral (HIV) infection.
• Disorder of haemostasis. These include headaches attributed to hypoxia and/or hypercapnia (such as high-altitude headache, diving headache and sleep apnoea headache), from hypothyroidism and fasting, cardiac cephalalgia, from dialysis, headache from arterial hypertension including pre-eclampsia and eclampsia.