Annals of Indian Academy of Neurology
IMAGES IN NEUROLOGY
Year
: 2022  |  Volume : 25  |  Issue : 3  |  Page : 489--490

Bilateral optic tract enhancement: An unusual imaging finding in neurosyphilis


Lakshminarayanapuram G Viswanathan1, Madhu Nagappa1, Doniparthi V Seshagiri1, Karthik Kulanthaivelu2, S Nagarathna3, Sanjib Sinha1,  
1 Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
2 Department of Neuroimaging and Interventional Neurology (NIIR), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
3 Department of Neuromicrobiolgy, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India

Correspondence Address:
Sanjib Sinha
Professor and Head, Department of Neurology, NIMHANS, Bangalore - 560 029, Karnataka
India




How to cite this article:
Viswanathan LG, Nagappa M, Seshagiri DV, Kulanthaivelu K, Nagarathna S, Sinha S. Bilateral optic tract enhancement: An unusual imaging finding in neurosyphilis.Ann Indian Acad Neurol 2022;25:489-490


How to cite this URL:
Viswanathan LG, Nagappa M, Seshagiri DV, Kulanthaivelu K, Nagarathna S, Sinha S. Bilateral optic tract enhancement: An unusual imaging finding in neurosyphilis. Ann Indian Acad Neurol [serial online] 2022 [cited 2022 Sep 27 ];25:489-490
Available from: https://www.annalsofian.org/text.asp?2022/25/3/489/345147


Full Text



 Clinical Description



A 51-year-old gentleman presented to our center with intermittent blurring of vision, transient holocranial headaches, and left hemisensory disturbances of 2 months duration. Six months before onset of these symptoms, he had hematuria which was treated with oral antibiotics. After 8 weeks, he developed a diffuse maculopapular rash over the trunk involving the palms and soles. Multiple enlarged non-tender and mobile cervical lymph nodes were evident on physical examination. At the time of evaluation at our center, visual acuity and fields by confrontation were normal. The pupils were reactive, no relative afferent pupillary defect was noted, and fundi were also normal. MRI findings are depicted in [Figure 1].{Figure 1}

Cerebrospinal fluid (CSF) analysis was remarkable for a lymphocyte predominant pleocytosis (41 cells, 100% lymphocytes) and elevated protein levels (66 mg/dL). Glucose levels were within normal limits. CSF and serum venereal disease research laboratory (VDRL) and Treponema Pallidum Hemagglutination Test (TPHA) were positive (titer: 1:2560). CSF for fungal cultures; smears for abnormal cells; Acid-fast bacillus (AFB), Gram's stain, and India ink staining; standard agglutination test for Brucella antibodies; enzyme-linked immunosorbent assay (ELISA) for antimycobacterial and cysticercal antibodies were not contributory. Serum and CSF studies for anti-Aquaporin-4 and anti-myelin oligodendrocyte antibodies were also negative. Visual evoked potentials and perimetry were normal.

 Discussion



Syphilis affects the nervous system in 5%–30% of affected individuals. The manifestations are varied and temporally related from the time of acquisition of the infection. Commonly described clinical phenotypes are the meningovascular, neuropsychiatric, and myelopathic forms.[1] Our patient presented early in the course of the disease (within a year) and probably represented the early stages of neurosyphilis.[2] MRI lesions in the vicinity of the rostral brainstem and optic tracts were suggestive of “gummas.” In a review of 156 cases of syphilis exhibiting gummas in the brain parenchyma, 64% of lesions were located in the cerebral convexities. In this particular series, no lesion was identified in the optic tract and about 5% of the gummas were distributed in the midbrain.[3] Hemianopia with unilateral optic tract gumma has been reported in a single patient from Japan.[4] Interestingly, our patient had no objective visual field defects on testing. Our case highlights that a high degree of suspicion and meticulous history-taking are indispensable tools that can aid in the diagnosis of this rare but treatable neurological illness in the modern era. In addition, optic tract enhancing lesions in the setting of CSF pleocytosis should make one consider syphilis as a differential diagnosis.

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.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Nagappa M, Sinha S, Taly AB, Rao SL, Nagarathna S, Bindu PS, et al. Neurosyphilis: MRI features and their phenotypic correlation in a cohort of 35 patients from a tertiary care university hospital. Neuroradiology 2013;55:379–88.
2Gonzalez H, Koralnik IJ, Marra CM. Neurosyphilis. Semin Neurol 2019;39:448–55.
3Fargen KM, Alvernia JE, Lin CS, Melgar M. Cerebral syphilitic gummata. Neurosurgery 2009;64:568–76.
4Iwamoto K, Aoyagi J, Kiyozuka T, Iwasaki Y, Fujioka T. Neurosyphilis with unilateral optic tract lesion causing homonymous hemianopia. Neurologist 2009;15:345–6.