|Year : 2019 | Volume
| Issue : 3 | Page : 166-169
Retrobulbar neuritis: Rare presentation in dengue fever
Atul Bhasin, RK Singal, Atul Prasad, Rahul Handa, Harsh Mittal
Departments of Medicine and Neurology, BLK Super Speciality Hospital, New Delhi, India
|Date of Submission||28-May-2019|
|Date of Decision||06-Jun-2019|
|Date of Acceptance||22-Jun-2019|
|Date of Web Publication||22-Jul-2019|
Dr. Atul Bhasin
1C/22, New Rohtak Road, Karol Bagh, New Delhi - 110 005
Source of Support: None, Conflict of Interest: None
Dengue fever is transmitted by the bite of infected female Aedes aegypti mosquito. There has been a worldwide resurgence of disease over the past few decades. Southeast Asia, American tropics, and subtropical countries have seen many epidemics in recent past, with the annual incidence of disease exceeding 50–100 million per year. Dengue fever is characterized by fever, malaise, headache, muscle ache, retro-orbital pain, purpuric rash, and bleeding diathesis due to thrombocytopenia. Neurological symptoms have been reported as changing clinical profile of dengue infection. Encephalopathy and encephalitis are being increasingly reported other than hemorrhagic cerebrovascular presentations. Ophthalmic complications involving the anterior and posterior chambers have been reported with varying incidence. Blurring of vision, scotoma, retinal hemorrhages, macular edema, and optic neuropathy have also been reported. We report here a rare case of retrobulbar optic neuritis in a case of dengue fever which showed complete recovery from ocular symptoms on recovering from dengue fever.
Keywords: Dengue fever, optic neuritis, retrobulbar neuritis
|How to cite this article:|
Bhasin A, Singal R K, Prasad A, Handa R, Mittal H. Retrobulbar neuritis: Rare presentation in dengue fever. Indian J Med Spec 2019;10:166-9
|How to cite this URL:|
Bhasin A, Singal R K, Prasad A, Handa R, Mittal H. Retrobulbar neuritis: Rare presentation in dengue fever. Indian J Med Spec [serial online] 2019 [cited 2020 May 25];10:166-9. Available from: http://www.ijms.in/text.asp?2019/10/3/166/264535
| Introduction|| |
Dengue fever, a flavivirus infection, is an arboviral disease which has four antigenically related serotypes (DEN 1–4). Dengue hemorrhagic fever (DHF) is a very severe and potentially fatal disease. Varied hematological manifestations are usually seen during the course of the disease. Neurological symptoms have been recognized and documented in dengue fever. We present here a case of dengue fever which presented with retro-orbital neuritis and showed complete recovery following treatment.
| Case Report|| |
A 33-year-old, nondiabetic, normotensive, homemaker presented to us with high-grade fever with chills, headache, myalgia, recurrent vomiting, loose stools with melena, and pain abdomen for 6 days. She developed acute-onset, rapidly progressive, painless bilateral loss of vision over 1 day which progressed to perception of light on admission. There was a single episode of melena on the day of admission. There was no history suggestive of any neurological, hepatobiliary, or colonic disease in the past. Her vision was normal prior to this episode. She was under replacement therapy for hypothyroidism, and her thyroid profile was normal 4 weeks back. Clinical examination revealed a dehydrated and toxic patient with tachycardia and hypotension (90/60 mmHg, right arm supine). Abdominal examination revealed epigastric tenderness with no guarding, rigidity, rebound tenderness, or organomegaly. Neurological examination revealed decreased visual acuity with perception of light in both the eyes. Both pupils were 3 mm not reacting to light. Rest of the central nervous system (CNS), cardiovascular, and respiratory examination was unremarkable. Investigation revealed thrombocytopenia, platelet count of 14,000 × 103/mm, deranged hepatic enzymes such as aspartate transaminase: 47.5 U/L (n: 10–35) and alanine aminotransferase: 107 U/L (n: 0–32), with normal prothrombin time and international normalized ratio. Rest of the biochemistry was normal. Urine microscopic examination showed trace proteins, leukocytes of 40–45/high-power field (HPF), epithelial cells of 8–10/HPF, and red blood cells of 6–8/HPF, with budding yeast cells and pseudohyphae. Malaria antigens were nonreactive. Dengue nonstructural protein 1 (NS1) antigen was positive, which was subsequently confirmed by enzyme-linked immunosorbent assay. Ultrasonography of the whole abdomen findings were suggestive of mild splenomegaly. Two-dimensional Echocardiography showed jerky septal motion, left ventricular ejection fraction 55%, normal diastolic flow velocities with mild mitral regurgitation, trace tricuspid regurgitation, and normal pulmonary artery systolic pressure. Ophthalmology and neurology consultation were sought in view of blurring of vision. Fundus examination was normal which did not reveal any disc pallor or edema. Macula and blood vessels were normal with no evidence of bleeding. A clinical diagnosis of bilateral retrobulbar optic neuritis secondary to dengue fever was opined. In view of the above, an urgent magnetic resonance imaging (MRI) brain was requested to rule out any central venous thrombosis or intracranial bleed. MRI brain (venography) contrast was done which showed a small focus of restricted diffusion with T2/fluid-attenuated inversion recovery hyperintensity in the midline splenium of the corpus callosum [Figure 1]. Lumbar puncture for neuro virus panel was planned but was deferred because the patient had severe thrombocytopenia. Visual-evoked potential (VEP) test by checker and goggle was done. It revealed 117.16 ms on the right and 119.7 ms on the left side by checker and 149.7 ms on the right 119.4 ms on the left side by Goggle stimulation test. Thus, prolonged bilateral P-100 latency was documented which was suggestive of optic nerve demyelination [Figure 2]. A diagnosis of retrobulbar optic neuritis secondary to dengue fever was made, and she was planned for pulse steroid therapy. After fluid resuscitation and correction of dehydration in triage and on becoming hemodynamically stable with no evidence of active bleeding, she was started on intravenous proton pump inhibitors and given high-dose methylprednisolone in the intensive care unit. Other supportive medications and fluids were continued. The patient was administered intravenous methylprednisolone (1 g intravenous daily for 3 days), which she tolerated well with no adverse effects. She improved significantly over the next 5 days, with visual acuity improving to finger counting and recovered to normal vision on day 3. She was started on oral steroid replacement therapy. A repeat VEP study was performed which revealed a significant improvement (prolonged P–100 latency on the left 115.5 ms, while the right side was normal) [Figure 3]. The patient was placed on tapering oral steroids and was discharged from the hospital with normal platelet counts. On routine follow-up, the patient had recovered and was asymptomatic.
|Figure 1: Magnetic resonance imaging brain (venography) contrast showing small focus of restricted diffusion, with T2/fluid-attenuated inversion recovery hyperintensity signal, in the midline splenium, of the corpus callosum|
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|Figure 2: Visual-evoked potential (by checker and goggle) revealing prolonged P-100 latency bilaterally, suggestive of optic nerve demyelination|
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|Figure 3: Visual-evoked potential studies revealing prolonged P–100 latency on the left (115.5 ms), while the right side is normal|
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| Discussion|| |
Dengue fever, a tropical infection seen in over 128 countries, is one of the most commonly encountered arboviral diseases (mosquito borne) and affects humans globally. Our patient had splenomegaly, jerky septal motion on echocardiography, leukocyturia, and candida on urine examination, which were possibly due to dengue viremia. Cardiovascular and neurological involvement in our patient in early stages and continuum of neurological presentation with bilateral visual loss made it a rare case. There is an emerging evidence of virus directly involving the CNS, and its neurovirulence affliction has been implicated due to viral proteins, ribonucleic acid, and immunoglobulins (Ig). Dengue infection is a common infection in travelers, although neurological and ocular symptoms have been infrequently reported in travelers. The exact incidence of neurological complications is not known, but encephalopathy and encephalitis have been reported in up to 6.2% of cases. The WHO in 2009, for the first time, considered neurological manifestations as one of the criteria for severe dengue infection, and these were primarily attributed to infection by serotypes DENV-2 and DENV-3. Acute blood loss due to melena leads to hypotension, causing acute hemodynamic compromise which, in turn, may lead to detrimental physiological consequences, by impairing or depleting the circulation of blood and oxygen to the brain and optic nerve. Impaired autoregulation of vessels, hypoperfusion, and secondary ischemic injury all may be contributing factors in visual loss. In our patient, there was a complete reversal of hypotensive shock with fluid correction, and there was no evidence of active gastrointestinal bleed, thus suggesting no ongoing neurological injury due to hemodynamic compromise. Ophthalmic complications have been reported in a few cases and usually present as a bilateral disease. Both anterior- and posterior-chamber diseases have been documented, and very rarely, optic nerve involvement has been seen as complication in dengue fever or DHF. Central scotomas, decreased vision, floaters, subconjunctival hemorrhage, uveitis, vitritis, retinal pigment epithelium mottling, foveolitis, choroidal effusion, and panophthalmitis can be present due to inflammatory reaction. Rarely, optic neuritis, neuroretinitis, and oculomotor palsies can be seen. An immune-mediated response, involving immune clearance mechanisms, has been postulated for neurological manifestations. Recognition of dengue viral antigens on infected monocytes initiates the release of cytokines with vasoactive and procoagulant properties, and these have been implicated as a mechanism of immunological injury. Optic nerve ischemia causing neuronal damage is secondary to hemorrhagic shock or circulatory failure, whereas optic neuritis appears to be indicative of an immunogenic response. Because our patient showed complete recovery of hemodynamic compromise on fluid resuscitation and there was evidence of only retrobulbar optic neuritis on VEP studies, an immunological insult to the nerve and not ischemic injury was thus suggested. The pathogenesis appears to be multifactorial, from neurotrophic, systemic, to immune-mediated effects of the virus. Interaction of multiple factors, i.e., direct viral infection, metabolic abnormalities, hemorrhagic disturbances, and autoimmune reaction, play an important role in the neuropathogenesis of dengue-associated neurological manifestations. DENV-2 and DENV-3, the more commonly associated viruses with neurological manifestations, usually appear within 2–30 days of febrile episode. Neurological complications, based on pathogenesis, can be classified as metabolic, direct viral invasion, or autoimmune. Irritability, altered sensorium, seizures, focal neurological deficit, and encephalitis are the most common presenting neurological manifestations. Myelitis, polyradiculopathy, optic neuritis, and acute disseminated encephalomyelitis (ADEM) are other less commonly seen presentations. Rarely, longitudinally extensive transverse myelitis, a spinal lesion covering more than three segments, and cerebellar syndromes have been reported. ADEM in dengue fever is suggestive of transient autoimmune reaction to myelin or unknown antigen involving white matter of the brain. Although there is no established treatment for ADEM, steroids have been advocated and found to be useful during active phase. Detection of anti-DENV immunoglobulin, viral RNA, or NS1 or isolating the virus from the cerebrospinal fluid establishes the diagnosis of neurological involvement in suspected cases. Autoimmune reactions and metabolic alterations have been seen in complicated dengue infections. Up to 50% mortality has been reported in dengue-associated encephalopathies. Optic nerve involvement in dengue fever is rare in spite of the high prevalence of dengue fever in tropical regions. The first case of optic neuritis was reported in 1989. Retrobulbar optic neuritis has been rarely documented and reported. Ours appears to be the first case of retrobulbar neuritis caused by dengue fever and confirmed by prolonged latency being documented on VEP and its complete reversal following treatment. Meningitis, syphilis, Lyme disease, and herpes zoster are infectious diseases known to cause retrobulbar neuritis. While diabetes mellitus, vitamin B12 deficiency, methanol poisoning, and autoimmune disorders such as systemic lupus erythematosus, sarcoidosis, and neuromyelitis optica are other noninfectious causes of retrobulbar neuritis. Ocular symptoms can be clinically divided into three types, namely, white eye with vision loss, red eye with no visual impairment, and painful red eye with visual impairment. On thorough search of literature, we could not find a documented case of dengue fever with retrobulbar neuritis. Our patient had multisystem involvement in the form of cardiovascular and neurological involvement. Patient had cardiac manifestations as hypotensive shock, regional wall motion abnormality of cardiac wall with neurological involvement, while neurological involvement presented as retrobulbar neuritis presenting as bilateral reversible visual loss. Dengue fever can present with varied features; thus, any new symptom during the presentation of dengue fever needs to be thoroughly evaluated, as multisystem involvement has been documented in the disease.
| Conclusion|| |
Dengue, now an endemic disease in tropical countries, often presents with hematological manifestations. Although it presents with multiple organ involvement and dreadful complications, bleeding and shock appear to be the most dangerous manifestations. Dengue fever and its hemorrhagic symptoms are easily diagnosed in patients presenting during epidemics and in endemic regions. Physicians should be aware of other rare manifestations of the disease while evaluating dengue fever in small minority of patients.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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