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| CASE REPORT |
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| Year : 2023 | Volume
: 16
| Issue : 1 | Page : 161-164 |
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Optic neuritis presented as the only manifestation of neurosyphilis
Tanima Roy1, Anusen Das Gupta2, Aneeka Rahnuma Islam1
1 Neuro-Ophthalmology Unit, Chittagong Eye Infirmary and Training Complex, Chittagong, Bangladesh
2 Department of Internal Medicine, Chittagong Medical College, Chittagong; Ministry of Health and Family Welfare, Government of Bangladesh, Bangladesh
| Date of Submission | 13-Mar-2022 |
| Date of Decision | 29-Aug-2022 |
| Date of Acceptance | 10-Dec-2022 |
| Date of Web Publication | 21-Feb-2023 |
Correspondence Address:
Tanima Roy
Chittagong Eye Infirmary and Training Complex, Chittagong
Bangladesh
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/ojo.ojo_66_22
 Abstract | | |
Here, we report a case of syphilis presented with optic neuritis to consider neurosyphilis as one of the differential diagnoses of optic neuritis. A 25-year-old male attended at outpatient department of chittagong eye infirmary and training complex institute with a history of a sudden loss of vision in the left eye for 20 days. On eye examination, the patient had reduced visual acuity on the left eye (6/60), and the left pupil showed a relative afferent pupillary defect and swollen left optic disc. No other abnormalities were found in a routine blood test and magnetic resonance imaging of the brain. Intravenous corticosteroid was administered for 3 days followed by oral corticosteroid. His vision was gradually improving within a month and became 6/9 in the left eye, but after a month, the patient returned with the blurring of vision in the same eye for 3 days. An extensive serum biochemical and serological test and cerebrospinal fluid (CSF) analysis was done including syphilis serology and human immunodeficiency virus (HIV) serology. Venereal disease research laboratory (VDRL) test and Treponema pallidum hemagglutination assay (TPHA) were found positive with high titer (1:1280) and rapid plasma reagin (RPR) titer of 1:64 in blood. The CSF analysis showed leukocytosis, and VDRL and TPHA were also found positive with high RPR titer. The HIV serology test was negative. The patient was treated with injectable ceftriaxone 2 g intravenously for 14 days and also injectable corticosteroid. His vision was improved within this period. Unilateral optic neuritis due to syphilis without other ocular features is uncommon but should be considered if a patient presents with visual loss and optic disc swelling. Early diagnosis based on clinical suspicion and prompt management is important to prevent visual impairment and subsequent neurological complications.
Keywords: Cerebrospinal fluid analysis, injectable ceftriaxone, neurosyphilis, optic neuritis
How to cite this article:
Roy T, Gupta AD, Islam AR. Optic neuritis presented as the only manifestation of neurosyphilis. Oman J Ophthalmol 2023;16:161-4 |
| Introduction | |  |
Syphilis is a sexually transmitted disease caused by Treponema pallidum. It is a chronic multisystem disorder in which the human is the only host. The incidence of syphilis continues to rise in the USA and Europe, and it is estimated that around 20% of patients with syphilis in the USA and Europe also have human immunodeficiency virus (HIV) infection.[1],[2] Syphilis increases among gay and bisexual men, in addition to underprivileged and heterosexuals, and also the use of crack cocaine and sildenafil user. Syphilis infection accelerates the progression of HIV; therefore, the resurgence of early syphilis with the global epidemic of AIDS has renewed interest in syphilis pathogenesis and the host response.[3]
Acquired syphilis is classified into four stages.[4] Primary syphilis is characterized by the formation of a painless chancre, which typically appears 2–6 weeks after infection at the site of inoculation. Lesion heals in 2–6 weeks even without treatment. Secondary syphilis occurs 4–10 weeks following infection and is characterized by nonspecific symptoms, such as fever and malaise, generalized rashes commonly in palms and soles. Latent syphilis is clinically undetectable and can persist for many years. Tertiary syphilis, usually characterized by neurologic and cardiovascular manifestations, occurs months to years following infection and may produce significant morbidity. Congenital syphilis can present during childhood with several systemic features.[5] Ocular involvement may be silent or present as scleritis, episcleritis, interstitial keratitis, uveitis, choroiditis, chorioretinitis, retinitis, vasculitis, optic neuritis, and perineuritis. All stages of syphilis can involve the eye. Neurosyphilis can occur at any stage.[6]
In a patient with syphilis, the presence of optic nerve abnormalities is strongly suggestive of central nervous system involvement, which should be considered synonymous with neurosyphilis.[7] The ocular feature due to neurosyphilis is relatively rare, particularly in immunocompetent cases, however, it can be also the presenting feature.[7],[8]
| Case Report | | |
A 25-year-old young man who was a cleaner by occupation coming from a low middle-class family attended at outpatient department of chittagong eye infirmary and training complex Institute with a history of sudden painless vision loss in his left eye for 20 days. He did not give any significant past medical history. He was a smoker who used to take 1 pack per day. He was neither a drug user nor had any history of alcohol intake. At first, he denied any sexual exposure but eventually agreed.
On examination, visual acuity of the right eye was 6/6 and the left was 6/60. Both pupils were round and regular. Direct and consensual reactions of both eyes were normal. The left pupil showed a relative afferent pupillary defect. Color vision by Ishihara test on the right eye, he read all plates but on the left eye, he could identify only two plates. The anterior segment of both eyes was found normal. The posterior segment showed a hyperemic left optic disc, margin blurred, swollen, and nerve fiber layer edema [Figure 1]a and [Figure 1]b. Fluorescence angiography showed hyperfluorescence of the left optic disc indicating edema, and the rest of the retina of both eyes was within normal limits [Figure 2]. Routine blood tests, urine tests, random blood sugar, and magnetic resonance imaging (MRI) of the brain were within normal limits. He was diagnosed with optic neuritis in the left eye and injectable corticosteroid was given for 3 days followed by oral corticosteroids as per the schedule of optic neuritis. His vision was gradually improving within 1 month and became 6/9 on his left eye. However, after a month, the patient returned with a blurring of vision in the same eye for 3 days. An extensive blood test was done including the Monteux test, C-reactive protein, venereal disease research laboratory (VDRL) test, T. pallidum hemagglutination assay (TPHA), and HIV serology. Notably, we also performed serum autoimmune antibody neuromyelitis optica immunoglobulin-G (NMO-IgG)/antibody to aquaporin-4 to exclude NMO, which was found negative. No abnormality was detected in all other blood tests except VDRL and TPHA in blood were found positive. TPHA had a high titer (1:1280 dilutions) and rapid plasma reagin (RPR) titer (1:64 dilutions) was also high. The patient then admitted having had a history of unprotected commercial sex 1 year ago, after which he had a single, painless ulcerated penile lesion healed without any antibiotic treatment. He did not notice any later symptoms attributable to secondary syphilis. We also examined but did not find any local genital skin lesions. Then, he was advised to do a cerebrospinal fluid (CSF) study. The CSF analysis showed leukocytosis (80 cu/mm lymphocyte), and VDRL and TPHA were found positive with TPHA titer found 1: 80 dilutions. RPR was also reactive. The biochemistry examination of CSF showed glucose 55 g/dl and protein 45 g/dl. No bacteria were found including tuberculosis. Adenosine di aminase was also negative (<5 U/L). Based on these clinical and laboratory examinations, he has been diagnosed with a case of neurosyphilis with optic neuritis. | Figure 1: Color fundus photograph of both eyes at the first visit. (a) The right disc was normal and macula and retina were within normal limits. (b) The left disc showed a margin blurred, disc hyperemic, nerve fiber layer edema macula, and the retina looked normal
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 | Figure 2: Fluorescein angiography of both eyes at the first visit: (a) Right eye fundus and disc looked normal. (b) The left eye showed early leakage from the left disc shown in the left eye. (c) The rest of the fundus of the left eye looked normal
Click here to view |
The ideal treatment of neurosyphilis is intravenous (IV) injection of 3–4 million units of aqueous crystalline penicillin at every 4 h for 10–14 days or intramuscular injection of 2.4 million units penicillin G procaine daily along with oral 500 mg probenecid four times daily for 10–14 days.[9] However, penicillin formulations are not currently available in our country. Therefore, as an alternative treatment, IV 2 g ceftriaxone had been given for 14 days.[10] The systemic steroid was also administered under the coverage of antibiotics. The patient's visual acuity was improved within 1 month. On the left eye, it was 6/9, could read five plates of Ishihara chart and the optic disc showed mild edema, which are the signs of improvement. He was advised to repeat VDRL, TPHA, and CSF study after 3 months.
| Discussion | | |
The most common causes of unilateral disc swelling in neuro-ophthalmology clinics are anterior ischemic optic neuropathy (AION), nonarteritic AION, optic neuritis, diabetic papillopathy, and other causes such as orbital compressive lesions. The normal brain images of this case excluded intracranial lesions. There were no signs found in the anterior segment and the retina was found normal in fundoscopy and fundus fluorescence angiography. Therefore, optic neuritis remained the most probable diagnosis for this patient. In most cases, the cause of optic neuritis is idiopathic. It can be secondary to demyelinating lesions, inflammatory, or less frequently due to autoimmune or infectious diseases, like syphilis. In syphilis, optic nerve involvement may be unilateral or bilateral and manifest as perineuritis, anterior or retrobulbaroptic neuritis, or papilledema. Optic perineuritis is usually asymptomatic. Optic neuritis is usually presented with a rapid visual loss, although as a whole, optic neuritis is rare and does not have any distinctive characteristics to distinguish it from nonsyphilitic involvement of similar distribution.[7] It is also noteworthy to mention that we performed an MRI of the brain instead of an MRI of the orbit to exclude extraocular neurological disorders such as intracranial space-occupying lesions and multiple sclerosis. Therefore, we might not get any common MRI findings of optic neuritis such as thickening of the optic nerve and hyperintensity.
When this patient came for the first time, he was also considered optic neuritis due to idiopathic cause, but when he came with recurrent optic neuritis all extensive blood investigations including NMO-IgG, tuberculosis, syphilis, and HIV were performed. Hence, although the history may not be suggestive of syphilis, patients with optic neuritis should be tested for syphilis keeping it as a differential diagnosis.
In this case, the primary infection was identified as a probable sexual contact followed by a compatible ulcerated penile lesion and no associated antibiotic therapy. The patient denied any symptoms/signs attributable to secondary syphilis. In fact, secondary manifestations can be so subtle that 60% of patients do not acknowledge them.[11] Diagnosis of neurosyphilis is based on the combination of signs and symptoms, as well as laboratory studies of blood and CSF.[12] VDRL and TPHA were found positive (1: 1280 dilution) with high RPR titer (1:64). Blood CSF analysis also showed leukocytosis, and VDRL and TPHA were found positive with high TPHA and RPR titer. Positive history, ophthalmological findings, positive treponemal blood, and CSF test result, we were able to affirm a diagnosis of optic neuritis with neuroretinitis and proceeded with a neurosyphilis treatment. At the 3-month follow-up, the patient's vision was found improved and he was advised to repeat blood and CSF analysis for syphilis serology, which also showed a decrease in high TPHA and RPR titers.
Optic neuritis is a common condition and may be the only presentation of uncommon diseases like neurosyphilis. As the incidence of syphilis is reemerging worldwide, clinicians should keep neurosyphilis as an important differential diagnosis in patients presenting with ocular signs even without pathognomonic features of syphilis.
Patient consent and statement of ethics
Written informed consent for the presentation and publication (for both text and photographs) of this case report was given by the patient. The authors have explained in detail about the purpose of this case report. The study was approved by the Institutional Research Review Committee. The study was done following the principles of the Helsinki Declaration.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understand that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
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