The big imitator strikes again: a case report of neurosyphilis in a patient with newly diagnosed HIV

BACKGROUND: Neurosyphilis is the result of an infection of the central nervous system caused by the spirochete Treponema pallidum. Its clinical presentation includes meningovascular syphilis, tabes dorsalis, and dementia paralytica, resulting in a wide range of symptoms such as psychosis, Parkinsonism, and depression.

CASE REPORT: A 49-year-old male was admitted to a psychiatric hospital because of social withdrawal and self-neglect, indicative of a major depression. A routine HIV-test was positive and resulted in an admission to the Antwerp University Hospital. Clinical examination showed Argyll Robertson pupils, a wide-based gait, absence of vibration sense in the lower limbs, and a MMSE-score of 25/30. Blood analysis revealed a CD4+ count of 99 cells/μL and a HIV viral load of 2,13 × 10(5) copies/mL plasma. A serum TPHA (T. pallidum hemagglutination assay) titre of 1/20480 and RPR (rapid plasma reagin) titre of 1/128 were detected. TPHA and RPR titre in the cerebrospinal fluid were, respectively, 1/10240 and 1/4. A brain MRI showed diffuse cortical atrophy and lesions in the white matter compatible with HIV-encephalopathy. The diagnoses of advanced HIV-infection and late neurosyphilis were made. HAART (highly active antiretroviral therapy) and high-dose IV penicillin G were started.

CONCLUSION: In all patients with new-onset dementia or untreatable psychosis, neurosyphilis should always be considered. Argyll Robertson pupils are regarded as pathognomonic of neurosyphilis. The management of neurosyphilis includes high-dose IV benzyl penicillin for 10 to 14 days. Close follow-up including a lumbar puncture after 6 months is warranted to ensure treatment recovery.