Headache and the eye

Because of the inextricable link between the eyes and headaches, ophthalmologists are often the first physicians to evaluate patients with headaches, eye pain, and headache-associated visual disturbances. Although ophthalmic causes are sometimes diagnosed, eye pain and visual disturbances are often neurologic in origin. Many primary headache disorders have ophthalmic features, and secondary causes of headache frequently involve the visual system. Both afferent and efferent symptoms and signs are associated with headache disorders. Moreover, the frontal or retro-orbital pain of some primary ophthalmic conditions may be mistaken for a headache disorder, particularly if the ophthalmologic examination is normal. This article reviews common ocular conditions that are associated with head pain, and some secondary causes of headache with neuro-ophthalmic neuro-ophthalmic manifestations.     

Ophthalmologic aspects of headache

Pain around the eye can be caused by local ophthalmic disorders or by disease of other structures sharing trigeminal nerve sensory innervation. In general, most ocular causes for pain also cause the eye to be red, thus alerting the examiner to the focality of the problem. However, conditions like eyestrain, intermittent angleclosure glaucoma or neovascular glaucoma, and low-grade intraocular inflammation can be painful and not be associated with obvious redness. Ocular signs and symptoms also occur with numerous other causes of headache. Double vision in association with periocular pain can result from orbital lesions, isolated cranial neuropathies, and cavernous sinus lesions. Pupillary abnormalities like Horner's syndrome may result from a variety of painful conditions, including cluster headache, parasellar neoplasms or aneurysms, internal carotid dissection or occlusion, and Tolosa-Hunt syndrome. Pain with a dilated and unreactive pupil may reflect a benign condition like Adie's syndrome or ophthalmoplegic migraine, or it may herald the presence of a life-threatening posterior communicating artery aneurysm. Headache and transient visual loss can be manifestations of classic migraine, or be symptoms of ocular hypoperfusion from ipsilateral internal carotid occlusion or increased intracranial pressure from pseudotumor cerebri. In a young patient, head pain with a fixed visual deficit may result from optic neuritis, in an older adult, temporal arteritis may be the culprit. Ophthalmologic aspects of headache thus encompass problems that range from simple and benign to complex and formidable.     

Phantom eye: features and prevalence. The predisposing role of headache

We prospectively evaluated the frequency, time-course and predisposing factors of phantom eye syndrome in 53 patients who underwent surgical eye amputation to cure ocular cancer. Before surgery, patients were classified as Group 1 (n=25) if they had no history of headache or Group II (n=28) if they were headache sufferers. Three clinical patterns were distinguished: phantom pain, non-painful phantom phenomena and photopsias. Their symptoms developed 7 days to 6 months after surgery, with peak incidence after 6 months (photopsia 43%; phantom pain 28%; non-painful phantom phenomena 62%). Phantom eye syndrome was more common in headache sufferers than in non-headache subjects. Headache sufferers were more prone to phantom pain, but more so to non-painful phenomena and photopsias. These findings are in accord with our previous results indicating that prima y headache sufferers are prone to phantom tooth pain.     

Neuroimaging in the Diagnostic Evaluation of Eye Pain

Ocular or eye pain is a frequent complaint encountered not only by eye care providers but neurologists. Isolated eye pain is non-specific and non-localizing; therefore, it poses significant differential diagnostic problems. A wide range of neurologic and ophthalmic disorders may cause pain in, around, or behind the eye. These include ocular and orbital diseases and primary and secondary headaches. In patients presenting with an isolated and chronic eye pain, neuroimaging is usually normal. However, at the beginning of a disease process or in low-grade disease, the eye may appear “quiet,” misleading a provider lacking familiarity with underlying disorders and high index of clinical suspicion. Delayed diagnosis of some neuro-ophthalmic causes of eye pain could result in significant neurologic and ophthalmic morbidity, conceivably even mortality. This article reviews some recent advances in imaging of the eye, the orbit, and the brain, as well as research in which neuroimaging has advanced the discovery of the underlying pathophysiology and the complex differential diagnosis of eye pain.     

Swollen and bloodshot eye following headache

A ruptured cavernous carotid aneurysm (CCA) with carotid cavernous fistula can appear as a benign headache but progress to a swollen and bloodshot eye overnight. A 66-year-old woman visited emergency department with sudden onset of pain behind her left forehead and vomiting. She was treated for a migraine-like headache and discharged. She presented again on the next day with a persistent headache and a swollen left eye with blurred vision. An ophthalmologic examination revealed erythema of the left lid and chemosis at the temporal and lower bulbar conjunctiva. A cranial nonenhanced computed tomography (CT) scan had been performed at her previous visit. The scan exhibited a nodular mass lesion involving the left cavernous sinus. CT angiography was subsequently used to determine that the lesion was a giant aneurysm in the left cavernous internal carotid artery, causing enlargement of the left ophthalmic veins. The symptoms of her left eye rapidly progressed to severe chemosis, edematous change over periocular region, and limited movements after 8?h. The patient received emergent lateral canthotomy and inferior cantholysis to avoid acute orbital compartment syndrome and was subsequently treated with stent-assisted coil embolization. A ruptured CCA is an urgent condition that requires rapid assessment of both cranial vascular and ocular lesions. A history of sudden onset headache with a nonpainful acute unilateral red eye may serve as a clue to prompt additional diagnostic studies and ophthalmologist evaluation. Adequate radiological studies and early endovascular intervention can reduce the likelihood of permanent ocular injury and vision impairment.     

The headache profile of idiopathic intracranial hypertension

The headache profile of idiopathic intracranial hypertension (IIH, pseudotumour cerebri) has not previously been prospectively studied. We administered a questionnaire to 63 cases at the time of diagnosis. Fifty-eight of the cases had headache and 93% of those with headache reported it to be their most severe ever. Patients characteristically noted a pulsatile headache of gradually increasing intensity that had awakened them. Daily headache occurred in 74% of those reporting headache. Pain in a nerve root distribution or retro-ocular pain with eye movement, uncommon with other headache disorders, help to differentiate this headache syndrome.     

Ocular Blood Flow Changes in Cluster Headache and Chronic Paroxysmal Hemicrania

Intraocular pressure and pulsatile ocular blood flow were recorded during and between attacks in patients suffering from cluster headache (n = 18) or chronic paroxysmal hemicrania (n = 7). Similarities, as well as significant differences, were observed between the two groups of patients, pointing to fundamental differences between the two disorders with regard to pathophysiology. Compared with healthy controls, the cluster headache patients demonstrated low pulsatile ocular blood flow values between attacks, with an increase to normal levels during pain. The chronic paroxysmal hemicrania patients, however, had normal values between attacks with a marked and significant increase to high values during attacks.     

Acute glaucoma presentations in the elderly

Acute glaucoma classically presents with severe pain, redness, and reduced vision in the affected eye, and severe cases can also have systemic symptoms. We report three cases of acute glaucoma in elderly patients. The diagnosis of acute glaucoma in a patient who presents with sudden onset of a painful, red eye with reduced visual acuity, a hazy cornea, and a fixed, semi-dilated pupil is comparatively straightforward. However, any patient with headache, malaise, or gastrointestinal disturbance, especially with clinical signs of an acute red eye and reduced vision, should alert doctors to the possibility of acute glaucoma. This is especially important in elderly people, who may not volunteer any specific ocular symptoms.     

Interictal Pain in Primary Headache Syndromes

Primary headache disorders are generally characterized by the pain, time course, and associated symptoms of their attacks, but often are accompanied by milder interictal pain. Patients with chronic migraine, chronic tension-type headache, hemicrania continua, and new daily-persistent headache have constant pain more often than not. Patients with trigeminal autonomic cephalalgias such as cluster headache commonly have interictal pain as well, usually much milder and unilateral to the side of attacks. Even those with rare headache types, including hypnic headache and trigeminal neuralgia, commonly have interictal pain. This review describes the incidence of interictal pain in primary headache disorders and suggests the significance and biological meanings of this pain.     

Ocular manifestations of autoimmune disease

Rheumatoid arthritis, juvenile rheumatoid arthritis, Sj?gren's syndrome, the seronegative spondyloarthropathies, systemic lupus erythematosus, multiple sclerosis, giant cell arteritis, and Graves' disease are autoimmune disorders commonly encountered by family physicians. These autoimmune disorders can have devastating systemic and ocular effects. Ocular symptoms may include dry or red eyes, foreign-body sensation, pruritus, photophobia, pain, visual changes, and even complete loss of vision. Because a number of these diseases may initially present with ocular symptoms, physicians should maintain a high index of suspicion to make a timely diagnosis. A thorough ophthalmic examination, including visual acuity, pupillary reaction, ocular motility, confrontation field testing, external inspection, and direct ophthalmoscopy with fluorescein staining, should be completed. In the patient with the complaint of a "dry eye" or a "red eye," simple tools such as the Schirmer's test or the blanching effect of phenylephrine can be useful in diagnosis. In general, managing the systemic effects with nonsteroidal anti-inflammatory drugs, corticosteroids, and immunosuppressive agents controls the ocular symptoms. When visual function is threatened, surgical therapy may be necessary. Early and accurate diagnosis with prompt treatment or referral to an ophthalmologist may prevent systemic and ocular disabilities.     

Classification and epidemiology of headache

Headache disorders are remarkably common. Like back pain, headache is a symptom that has a broad range of possible causes. Diagnosis of primary headache disorders (migraine, tension-type headache, cluster headache) depends on systematic exclusion of secondary disorders and systematic identification of the specific features of the primary disorders. Thus, migraine should be viewed as an episodic syndrome of pain, involving intracranial structures associated with other neurologic disturbances. Because of the large number of potential etiologies, clinicians must approach headache classification systematically. In this chapter, we provide an overview of headache classification followed by discussions of epidemiology.     

Headache Currents Commentary

Neuro‐ophthalmology is a field that interfaces intimately with headache medicine. Examples include common and uncommon visual disturbances related to migraine, painful loss of vision, eye pain, photophobia, pupillary disorders, and painful ophthalmoplegia. There are often articles relevant to headache specialists that are published in the ophthalmic literature. This commentary highlights 2 interesting clinical articles. All neurologists and headache medicine specialists should read the review on photophobia by Digre and Brennan as it is relevant, clinical, and comprehensive. The literature review on topiramate‐related acute angle‐closure glaucoma provides us with useful information about the epidemiology and pathophysiology of this rare but potentially vision‐threatening condition that may occur with the most widely used of migraine preventives.     

Chronic pain disorders and headache chronification

It is estimated that nearly half of the global adult population suffers from an active headache disorder, most of whom experience attacks on an episodic basis. The transition from episodic to chronic headache is a poorly understood process. Epidemiological findings demonstrating comorbidity and common risk factors suggest that headache progression or prognosis may be related to the presence of other chronic pain disorders. This review highlights findings from population-based studies on headache and other pain disorders and how they relate to each other, with a focus on understanding headache chronification. We also consider the limitations and methodological challenges in understanding how two different chronic pain disorders may be related.     

Diagnostic Criteria for Screening Headache Patients for Temporomandibular Disorders

Patients with temporomandibular disorders frequently suffer from headache. The purpose of this study was to develop a simple screening exam which would allow the physician to identify headache patients with coexisting temporomandibular disorders. Twenty-eight migraine and 27 tension headache patients were identified by board certified neurologist and then were examined by a dentist for signs of temporomandibular disorders. These patients were then compared to 63 patients with temporomandibular internal derangements and 62 patients with myofascial pain dysfunction. Comparisons of the clinical signs showed that the temporomandibular internal derangement and myofascial pain dysfunction patients differed significantly from the headache patients in regards to specific signs of jaw dysfunction. The presence of reciprocal clicking of the temporomandibular joint or pain with maximum jaw opening and pain upon palpation of the temporomandibular joint distinguished temporomandibular internal derangement patients from headache patients. These criteria have a sensitivity of 92% and specificity of 91%. Pain on palpation over the temporomandibular joint, or pain with maximum jaw opening using passive stretch, and pain with lateral movement of the jaw, distinguished myofascial pain dysfunction patients from headache patients. These criteria have a sensitivity of 77% end specificity of 85%. By using these screening tests, the physician can identify the concurrent existence of temporomandibuler disorders in headache patients and triage the patient to a clinician knowledgeable in the diagnosis and treatment of temporomandibular disorders for further evaluation.     

Reduction of calcitonin gene-related peptide in jugular blood following electrical stimulation of rat greater occipital nerve

Although it is known that pain in the forehead may be induced by neck abnormalities, the actual neck-head connections responsible for development of pain in trigeminal areas are poorly understood. Vasoactive neuropeptides released from sensory fibres, such as substance P (SP) and calcitonin gene-related peptide (CGRP), have been considered as important elements in headache pathophysiology. The levels of CGRP-like immunoreactivity (LI) were measured bilaterally in the jugular blood (52 rats) and intraocular aspirates (66 rats) following electrical stimulation of the left greater occipital nerve, and in the jugular blood of 13 control animals. One-third of the stimulated rats had varying combinations of conjunctival injection, tearing, diminished eye aperture and miosis or mydriasis on the stimulated side. The other two-thirds exhibited no ocular signs. Significantly lower levels of CGRP-LI were present in the jugular blood on the stimulated side in comparison with control rats. There was comparatively lower CGRP-LI on the non-stimulated side as well, but to a lesser extent. Significant differences between the stimulated and the non-stimulated side were present, particularly in the tearing/diminished eye cleft group. It is proposed that stimulation of the rat GON inhibits the trigeminal system (reduction of CGRP-LI) and possibly activates parasympathetic fibres (ocular changes).     

Ophthalmology

The Headache Classification Subcommittee of the International Headache Society classifies headaches related to eyes as "Headache attributed to disorder of eyes" in the International Classification of Headache Disorders; 2nd Edition(ICHD-II). It consists of "Headache attributed to acute glaucoma", "Headache attributed to refractive errors", "Headache attributed to heterophoria or heterotropia(latent or manifest squint)", "Headache attributed to ocular inflammatory disorder". But other causes of headache related to eyes exist. For example, dry eye causes the headache. This article mentions to "Headache attributed to disorder of eyes" in ICHD-II, and additionally, describes other causes of headache associated with disease of eye.     

Psychological trauma in chronic pain: Implications of PTSD for fibromyalgia and headache disorders

The association of traumatic exposures with posttraumatic stress disorder (PTSD) and other mental health conditions is well known. Patients with chronic pain, particularly headache disorders and fibromyalgia (FM), associated with psychological traumas need a special management strategy. Diagnosis of headache disorders and FM in traumatized patients and collecting the clinical history of a traumatic event or diagnosing PTSD in chronic pain patients is of great importance. Psychotherapy and pharmacotherapeutic options should be started on patients with comorbid PTSD and headache disorders and/or FM.     

Chronic daily headache in the absence of medication overuse: Is daily or continuous pain more treatment-resistant than chronic daily headache with pain-free days?

To our patients, their families, and treatment providers who may not be headache specialists, chronic daily headache (CDH) would appear to refer to headache disorders marked by the presence of daily pain over an extended period of time. To the headache specialist, in contrast, CDH represents a family of headache disorders in which pain occurs from 15 to 30 days each month [1], now reflected in the International Headache Society (IHS) criteria for chronic migraine (CM) or chronic tension-type headache [2]. The IHS classification does not distinguish between daily CM and intermittent CM marked by at least some pain-free days [3]. Research studies and clinical reports of the diagnostic entities subsumed under CDH often include patients with pain-free days and those with true daily pain.     

Are altered smooth pursuit eye movements related to chronic pain and disability following whiplash injuries? A prospective trial with one-year follow-up

OBJECTIVE: To evaluate the ability of early smooth pursuit testing to predict chronic whiplash-associated disorders, and to study whether the presence of abnormal smooth pursuit eye movements at one-year follow-up is associated with symptoms at that time. DESIGN: Prospective cohort study with one-year follow-up. SETTING: The study was carried out at a university research centre and participants were recruited from emergency units and general practitioners. SUBJECTS: In all, 262 participants were recruited within 10 days from a whiplash injury. MAIN MEASURES: Smooth pursuit eye movements were tested with electrooculography (EOG) an average of 12 days after a whiplash trauma and again after one year. Analyses of EOG recordings were computerized. Associations between test results both from baseline and one-year tests and self-reported neck pain, headache, neck disability and working ability one year after the car collision were determined. RESULTS: Results of early eye movement tests were not associated with the prognosis. Reduced smooth pursuit performance when tested in static cervical rotation at the one-year follow-up was significantly associated with higher neck pain intensity at that time (regression coefficient 0.8, 95% confidence interval (CI) 0.04-1.5), but the association was too weak for the test to discriminate between recovered participants and those with lasting symptoms. CONCLUSIONS: Although reduced smooth pursuit performance at one-year follow-up was associated with persistent neck pain, smooth pursuit eye movement tests are not useful as predictive or diagnostic tests in whiplash-associated disorders.