Patients commonly present to an optometrist on account of headache. These patients may be self-referred, but it is also common practice for GPs to advise their patients with headache to see an optician.
The vast majority of headaches are harmless, but the occasional patient is presenting with serious pathology and this is when the diagnosis should not be missed. An optometrist is uniquely equipped with the knowledge and with the instrumentation, which should allow no case with serious pathology to slip through.
Primary benign headaches with no underlying pathology account for the symptoms of 90 per cent of all headache sufferers. Secondary headaches are sinister and are accounted for by an underlying pathology, which includes potentially fatal conditions such as tumours, aneurysms, vascular diseases and systemic infections.
Types and causes of headache
- Primary benign headaches
- Visually-induced headaches
- Painful eye conditions
- Painful orbital conditions
- Neurological conditions
- Cerebral space-occupying lesions
- Skeletal conditions
- Vascular conditions.
Primary benign headaches
The most common causes of primary benign headaches with no pathology are tension-type headache, chronic daily headache and cluster headache. There is commonly a long history. The occurence of the headache is unrelated to visual concentration.
Visually-induced headaches
These headaches relate to what has traditionally been called asthenopia. Asthenopia simply means weakness of vision and is responsible for the visually-induced headache that follows visual activity. Asthenopia is characterised by early tiring of the eyes accompanied by eye pain, headache and by blurred vision. Its causes may lie within the visual system, or be at a psychological level.
The visual system causes are refractive or muscular. The refractive causes include uncorrected refractive error, the onset of presbyopia, aniseikonia and incorrect glasses. Incorrect glasses may carry the wrong refractive correction, or may be decentred, inducing a prism effect. The next group of causes are muscular and relate to the ocular muscle imbalances or heterophoria and to accommodation/convergence anomalies, either inadequate or excessive. Note that plus glasses may induce or aggravate exophoria and minus glasses may do the same for esophoria.
The patient with psychological asthenopia may also show hysterical visual symptoms such as reduced visual acuity and reduced field of vision. The patient is often a child whose school performance falls short of the parent's expectation.
Painful eye conditions
The painful eye conditions which may present as headache are:
- Glaucoma
- Uveitis
- Keratitis
- Episcleritis and scleritis
- Optic neuritis
- Ocular ischaemia
- Zoster.
The recognition that the patient has an eye condition may be obvious from the observation of an inflamed eye, as in episcleritis and in scleritis when it is anterior, but in posterior scleritis and in optic neuritis there are no obvious signs.
Glaucoma
Eye ache and headache occur when the ocular pressure rises above 50mmHg. The patient may well fail to identify that the pain is originating in the eye and describe their condition as headache. The vision is reduced and the eye red and watering. Angle-closure glaucoma is associated with hypermetropia.
The diagnosis of angle-closure glaucoma may also be less than obvious when the patient has suffered a subacute attack and presents with normal ocular pressure. The evaluation of the anterior chamber angle is then important.
Uveitis
Uveitis presents with a painful red eye and eye ache or headache which is aggravated by exposure to light. There may be miosis and flare and cells in the anterior chamber or in the vitreous.
Keratitis
Keratitis is most usually due to a corneal ulcer and presents with pain, watering, blurred vision and photophobia. The diagnosis is confirmed by observing ulceration and infiltration in the cornea.
Episcleritis and scleritis
In episcleritis there is a patch of inflammation, commonly affecting one eye, but the condition may be bilateral. It is sometimes nodular in appearance. In scleritis the deeper layers of the sclera are affected and the condition is more painful than in episcleritis.
Optic neuritis
The patient presents with reduced vision and eye ache. The ache of optic neuritis is characteristically aggravated by looking up to the affected side. There is reduced dark adaptation, which shows as a raised retinal threshold on field testing, which may also show a central scotoma.
The pupil direct light response is reduced. The optic disc appearance is normal when the optic neuritis is posterior and affected by papillitis when anterior.
Ocular ischaemia
Ocular ischaemia presents with ocular pain, lacrimation and reduced vision. The level of vision is likely to be variable and there may be field loss or diplopia. The examination is likely to show a red eye with a miosed pupil and flare in the anterior chamber. The ocular movements may be defective. The fundus may show papilloedema and retinal soft exudates. The ocular pressure may be lowered or raised.
Zoster
Zoster ophthalmicus presents with ache around one eye before the characteristic rash makes the diagnosis obvious. Later, the patient may continue to experience an ache of the fifth nerve distribution for months after the rash has gone. This is postherpetic neuralgia.
Painful orbital conditions
The painful orbital conditions include infections and vascular conditions, such as cavernous sinus thrombosis. There is often proptosis and the ocular movements are likely to be restricted. The presence of painful proptosis warrants instant referral.
Neurological conditions
The neurological conditions which may present as headache are:
- Migraine and its variants
- Neuralgias
- Nerve root pains
- Meningism
- Cerebral space-occupying lesions
- Raised intracranial pressure.
Migraine and its variants
The diagnosis of migraine is not difficult when the patient gives a history of recurrent attacks, but you may be seeing a patient following their first attack. There is often a family history of headaches. Migraine usually presents for the first time in youth or in the younger adult. An apparent first-time presentation of migraine in an older person should be treated with suspicion.
The experience of migraine varies considerably between one individual and another. The headache is not necessarily preceded by an aura, but when a preceding aura is well described by a patient, no other cause of headache is at all likely. The headache is always one-sided and on the opposite side to the aura, although different sides may be affected on different occasions. The headache is described as throbbing and may last from a few minutes to many hours. A headache lasting continuously for several days is not migraine. Associated symptoms are photophobia, nausea and somnolence.
The aura that precedes migraine may take several forms, the commonest being a visual aura. The typical visual aura usually lasts from five to 20 minutes and begins with a shimmering central spot, which expands and develops into a central scotoma. The margin of the central scotoma becomes defined by a flickering zigzag line which is brightly coloured and named teichopsia. There may be field of vision loss. The teichopsia and field loss take the identical form in each eye the field loss being an homonymous hemianopia. Other forms of aura are gustatory, auditory, parasthesia, aphasia and paresis. In the rare ophthalmoplegic migraine the extraocular muscles are affected.
The mechanism of migraine has been thought to be due to vascular disturbance affecting the visual cortex, but this cannot explain the geometric pattern of teichopsia and a progression of electrical activity from neurone to neurone in the occipital cortex may be responsible.
Ophthalmic artery migraine is a rare migraine variant which affects the vision of one eye. Field loss is characteristic and the lower field is the more usually affected. Positive scotomata sometimes occur and are described by the patient as bright and glowing shapes. Recovery within a few minutes is usual, but very rarely a permanent scotoma may remain. It seems likely that visual migraine is accounted for by defective flow in the ophthalmic artery or in one of its branches.
Periodic migrainous neuralgia is characterised by paroxysms of intensive unilateral headache of short duration, with pain in or behind the eye, and unlike ordinary migraine, it is the same side every time. The eye may be red and watering, with blurred vision at the time of the attack.
Neuralgias
The neuralgias which concern us here are trigeminal neuralgia and nasociliary neuralgia. Neuralgias are sensations arising in sensory nerves in the absence of any known pathology and as such are harmless. Pain is characteristically very sharp and of very short duration, which distinguishes it from nerve root pain.
Nerve root pains
Here we are concerned with trigeminal nerve root pains. Nerve root pains are due to compression or inflammation affecting the nerve root. The pain is continuous and in the trigeminal distribution, or in one of its branches and is associated with numbness in the same area. It may follow truama.
Meningism
Meningism is the name given to pain arising in the meninges and has very serious implications. Its causes are meningitis and haemorrhage into the meninges. In meningitis, the patient is likely to be ill and febrile. There may be a rash that does not blanch on pressure. In the case of haemorrhage, there may be a history of previous attacks. Neck stiffness is usual.
Cerebral space-occupying lesions
Cerebral space-occupying lesions are tumours, aneurysms and abscesses. Tumours and aneurysms can expand gradually over a long period without symptoms. However, they can then present quite suddenly with headache. This can occur when a rapid expansion or a haemorrhage occurs. Meningism is then associated with subarachnoid haemorrhage. The key diagnostic features of cerebral space-occupying lesions are the association of field of vision loss or of ocular motility defects.
Raised intracranial pressure
The patient may complain of blurred vision and field of vision testing may show defects. The fundus may show papilloedema. Raised intracranial pressure may be due to cerebral space-occupying lesions and occasionally may occur without identifiable pathology (benign intracranial hypertension). The patient may have diplopia with an esotropia due to sixth-nerve paresis. This is called 'the false localising sign' since the paresis is due to the pressure and not to any lesion affecting the nerve.
Skeletal conditions
The skeletal conditions associated with headache are neck arthritis and sinusitis. Headache of sinusitis is often around the eye when the frontal or ethmoid sinuses are infected. Arthritis of the temperomandibular joint and the neck can each cause pain radiating into the head. The brow is likely to be tender to touch in sinusitis.
Vascular conditions
The vascular conditions causing headache are temporal arteritis, hypertension, carotid occlusion, ocular ischaemia (see painful eye conditions above), and cavernous sinus thrombosis. Aneurysms may also be included here, but have been considered earlier.
Temporal arteritis
This is one of the most urgent conditions that presents with headache. Untreated it can lead to a stroke or to vision loss, but with early corticosteroid treatment the prognosis is good. The patient with a headache due to temporal arteritis is likely to be generally unwell. The ache and tenderness is typically in the temporal region, but may be elsewhere and there may be pain on eating. There may be a history of blurred vision or of amaurosis fugax. The fundal examination is typically normal.
Palpation of the temporal artery may show a thickened tender and pulseless artery. Temporal artery palpation is not difficult and takes only a few seconds.
Hypertension
The headache of hypertension tends to be occipital or vertex and is characteristically worse on waking in the morning. The appearance of the fundi can be diagnostic when hypertensive retinopathy is present. Look for narrowed arteries, soft exudates and haemorrhages.
Cavernous sinus thrombosis
Cavernous sinus thrombosis has an acute presentation with eye pain, reduced ocular movement, proptosis and ptosis. There is usually marked conjunctival swelling.
Carotid artery occlusion
Carotid artery occlusion causes pain in the eye when it is responsible for ocular ischaemia.
Patient management
History
Good history taking will separate most patients with primary headaches from those with secondary headaches and may well lead you close to the actual diagnosis before performing any examination:
Questions
Date of commencement of headache?
Frequency of occurrence?
Duration of each occurrence?
Severity of headache?
Assess by impact on daily life
Site in head affected?
Unilateral suggests migraine
Relationship to visual activity?
Visually-induced headache follows visual activity
Wake with headache?
Waking with headache excludes visual cause
Associated symptoms?
Visual disturbance suggests migraine, but also occurs in other conditions
Medication?
Excessive medication may be causing or aggravating the headache. (Medication overuse headache).
Key considerations to separate benign from sinister
The age of the patient
The very young or the aged are more likely to have sinister headaches
Time onset of headaches
History of more than five months likely benign
Duration of present headache:
Persisting for several days: May be sinister
Very severe headache: Sinister
Waking with headache: Possibly sinister
Poor health. Feeling unwell: Sinister
Associated or atypical new symptoms: Sinister
Including: Blurred vision, diplopia, rash, neurological defect, vomiting, neck stiffness
Following accident or injury: Sinister.
Examination
The examination follows the normal optometrist's routine, with special attention to some areas:
Refraction and VA, distance and near
Accommodation and convergence
Ocular muscle balance and ocular movements
Pupil responses
Fields of vision
This is a crucial test and should be repeated each time the patient is seen
Eye examination with particular note of redness or proptosis
Does AC look shallow or angle narrow?
Ocular pressure
Other checks:
Aggravation of pain by eye movement
Neck stiffness
Palpation of brow for tenderness
Palpation of temporal arteries for pulses and tenderness
Fundal examination
State of vessels, presence of haemorrhages or exudates, condition of disc. Is there papilloedema?
? Nicholas Phelps Brown is a consultant ophthalmologist on Harley Street
