Abstract
Unilateral periocular pain accompanied by unilateral autonomic symptoms, which are the cardinal signs of cluster headaches or other trigeminal autonomic cephalalgias (TACs), could be present with other diseases involving the retro-orbital or orbital structures (1–4). Among such diseases, posterior scleritis has rarely been described as a cause of unilateral periocular pain and autonomic symptoms. The early presumptive diagnosis of posterior scleritis is important, despite its rare occurrence, due to the possibility of permanent visual loss through its recurrence (5, 6). We describe a patient with posterior scleritis that was attributed to recurrent unilateral cluster-like headaches.
Case report
A 52-year-old woman sought evaluation at our hospital for left-sided retro-orbital pain, which developed with moderate intensity [visual analogue scale (VAS) = 4] without other ocular symptoms. Squeezing and compressing pain was sustained around the retro-orbital area and paroxysmal electrical sharp pain occurred in the left frontotemporal area. The pain intermittently exacerbated to very severe intensity (VAS 9–10), lasting 1–3 h, with a frequency of two to four times a day. The severity of the pain progressed over the initial 3 days. On the third day after symptom onset, she experienced very severe exacerbation of the pain, which was associated with conjunctival injection, lacrimation, blurred vision and central horizontal scotoma. The pain was not exacerbated during eye movement. At presentation, there was conjunctival injection and increased lacrimation in her left eye. Routine neurological examination was normal without meningeal inflammatory signs. Ophthalmological examination showed normal pupil size, normal light reflexes and normal intraocular pressure (14 mmHg) bilaterally, but decreased visual acuity in the left eye (20/40 in the left eye vs. 20/20 in the right eye). On perimetry examination, neither a field defect nor a central scotoma was present. Fundoscopic examination and fluorescein angiography revealed mild retinal and optic disc oedema in the left eye.
On further history taking, she had experienced similar headaches two to three times a year for the past 10 years. The previous headaches had usually developed on the left side, but sometimes on the right side or both sides. Interestingly, the pain was never accompanied by autonomic symptoms during the first 2–3 days. When the pain increased to severe intensity, she experienced terrible shock-like pain. Subsequently, conjunctival injection and lacrimation developed and the pain intensity gradually decreased for 6–7 days. However, she had never experienced any visual symptoms, such as decreased visual acuity or central scotoma. She was previously treated with impression of dry-eye syndrome or conjunctivitis by two ophthalmologists. She self-administered acetaminophen without efficacy.
On magnetic resonance imaging (MRI) evaluation, the intracranial structures, including the cavernous sinus, were normal. The optic nerves were also normal, but abnormal contrast enhancement was noted in the left posterior sclera, indicating inflammation of the posterior sclera (Fig. 1). Cerebrospinal fluid (CSF) analysis included a clear colour, white blood cell (WBC) count of 55 cells/μl (lymphocytes 80%), CSF protein of 42 mg/dl (normal range < 45 mg/dl) and a CSF/serum glucose ratio that was within the normal range. The visual evoked potentials were normal. On serological evaluation, rheumatoid factor was increased 90-fold (1640 IU/ml) above the upper limit of normal. Other serological markers, such as antinuclear antibody, antineutrophil cytoplasmic antibody, anti-Scl-70 antibody, anticentromere antibody, C3, C4, IgG, IgA and IgM fractions, antiphospholipid antibody and β2-microglobulin, were within the normal ranges.
Brain magnetic resonance imaging with gadolinium enhancement shows enhancement of the lining of the posterior sclera in the left eye (arrow), indicating posterior scleritis. Moreover, enhancement of the anterior sclera and mild thickening of the choroid membrane are also observed in the left eye, which is suggestive of inflammation in the surrounding tissues. (a) Axial. (b) Coronal T1-weighted image.
We diagnosed her with recurrent posterior scleritis and aseptic meningitis presenting with a unilateral headache and unilateral autonomic symptoms. Since there was evidence showing an inflammatory reaction in the retina and anterior optic nerve, she was given high-dose intravenous steroid treatment (methylprednisolone, 1 g/day) for 5 days. Her headache was dramatically improved with steroid treatment. A follow-up lumbar puncture revealed improved CSF parameters (WBC 9/μl; protein 32 mg/dl), and the left optic disc swelling was reduced. On follow-up examination 2 weeks after the onset of symptoms, her visual acuity was completely recovered (20/20); however, the subjective central scotoma continued for 2 months.
Discussion
Our patient had constant hemicranial pain that resembled a TAC when the symptoms, including autonomic symptoms, were fully manifest. The characteristics of the headaches, such as severe unilateral retro-orbital pain associated with autonomic symptoms lasting for 60–180 min, and clustering of attacks for 9–10 days with periodic occurrence, were similar to cluster headaches, a prototype of TACs (1–3). However, retro-orbital pain for 3 days before starting of autonomic symptoms and alternating sides, or bilateral occurrence of attacks, are not characteristic of cluster headaches. Moreover, the presence of abnormal physical findings, including decreased visual acuity and central scotoma, could differentiate her headaches from cluster headaches (1–3). Based on MRI and an ophthalmological evaluation, we determined that her headaches resulted from posterior scleritis of the left eye. Since our patient also had aseptic meningitis without any findings suggesting other specific causes, and had a significantly elevated rheumatoid factor, we diagnosed her with recurrent posterior scleritis and aseptic meningitis associated with rheumatoid factor. With the diagnosis and rapidly developed ophthalmological abnormalities, we decided to use high-dose steroids, even though her symptoms were previously improved without specific treatment by her previous history.
Posterior scleritis is a rare and underestimated scleral inflammatory disease, because it often presents without specific signs of ocular inflammation (5, 6). Various diseases, including autoimmune connective disorders and infectious diseases, are often accompanied by posterior scleritis (5, 6), but rheumatoid arthritis is the most common associated disease and often presents with scleral inflammation without other systemic manifestations (7, 8). The most common symptoms of posterior scleritis are pain, decreased visual acuity and redness of the eye. Furthermore, posterior scleritis can be associated with ptosis, proptosis and eyelid oedema. Therefore, recurrent posterior scleritis without visual symptoms, such as the past attacks in the present case, is easy to misdiagnose as a cluster headache or other TAC. However, it is important to differentiate this inflammatory ocular disorder from TACs because posterior scleritis often results in permanent loss of vision through its recurrence and it can be prevented by accurate diagnosis and treatment. Although retro-orbital pain is known as the most common symptom of posterior scleritis, the characteristics of pain have been described in only one report (9). Specifically, the pain also preceded the other associated symptoms, and decreased visual acuity and central horizontal scotoma were present, just as in our case (9). Therefore, we suggest that a headache with these characteristics should be differentiated from TACs and considered a secondary headache caused by an ocular inflammatory disease, including posterior scleritis.
For the diagnosis of cluster headaches and other TACs, it is important to differentiate the headaches from secondary causes, especially ocular diseases (2–4), and if there are atypical findings, the diagnosis of cluster headache should be tentative until further studies are completed. Among headaches associated with eye disease proposed by the International Headache Society (1), acute angle closure glaucoma and ocular inflammatory diseases could mimic TACs through overlapping clinical symptoms (2, 3). Acute angle closure glaucoma, a relatively well-recognized disease, is often present with intense unilateral pain, conjunctival injection and ptosis. Since this condition is a true ophthalmological emergency, correct diagnosis is essential through examination of intraocular pressure and gonioscopy. Fortunately, acute angle closure glaucoma can be differentiated from cluster headache more easily and promptly when considering the characteristic findings, such as intense conjunctival injection, poor vision, and mid-dilated and poor-reactive pupils (2, 3). Ocular inflammatory diseases are also characterized by red eye and photophobia and could be diagnosed by slip-lamp examination, except posterior scleritis. However, the pain characteristics, aetiology, disease course and treatment of ocular inflammatory diseases are not well-recognized despite numerous clinical descriptions and classifications (2, 3). Moreover, miscellaneous inflammatory ocular diseases, including posterior scleritis, can often be overlooked because they are unfamiliar entities to neurologists and headache specialists, as well as ophthalmologists. For improvement in establishing an accurate diagnosis, careful history taking, physical examination and appropriate imaging studies are needed. Moreover, a detailed headache symptom inventory associated with an inflammatory ocular disorder should be obtained.
Footnotes
Competing interests
None to declare.