Description

A previously healthy 30-year-old bisexual African man was admitted with a 3-month history of weight loss, paroxysmal shooting pains and paraesthesia of both lower limbs and difficulty in walking. He denied progression of visual symptoms such as blurred vision with reading and near work, photophobia, anisocoria or visual loss. The Mini-Mental State Examination was normal (30/30). He was alert, oriented to time, person and place with a Glasgow Coma Scale of 15/15. His body mass index was 17 kg/m². There was generalised wasting syndrome, cervical lymphadenopathy and diffuse hair loss of the scalp and eyebrows. There was no urinary incontinence.

Visual acuity without correction (20/20), visual fields, intraocular pressures (14 mm Hg) and fundoscopy were normal in both eyes. Ocular motility was full bilaterally with no nystagmus. The pupils, however, were 6.0 mm in diameter on room light bilaterally, unreactive to light or accommodation (Video 1, segment 1). Slit lamp examination of the anterior segment was within normal limits in both eyes. Administration of eye drops with 0.125% pilocarpine produced bilateral pupillary constriction demonstrating cholinergic sensitivity (Video 1, segment 2). Gait was ataxic. Romberg’s sign was positive. Muscle power in all limbs were grade 5/5 (Medical Research Council Scale) with normal tone. Babinski sign was negative with hyporeflexia in patellar and Achilles tendons bilaterally. Posterior column sensation for light touch, joint position and vibration sensation were impaired below the anterior superior iliac spine. The rest of the examination was normal.

Serology for HIV ELISA and Venereal Disease Research Laboratory (VDRL) testing (1:64 dilutions) and fluorescent Treponema pallidum antibody absorption (FTA-ABS) test (4+) were positive confirming HIV/AIDS with syphilis coinfection. VDRL test (1:32 dilution) and FTA-ABS test (3+) were positive in cerebrospinal fluid (CSF). The HIV viral load was 356 398 RNA copies/mL, and the CD4 +T cell count was 110 cells/µL (reference values 410–1590). The international HIV Dementia Scale was normal (12/12). Extensive medical investigations results are shown in table 1. CSF analysis revealed clear, colourless fluid with normal opening pressure (15 cm of H₂O), moderate pleocytosis with 0.042 x 10⁹L white cell count, 81% lymphocytes, 9% polymorphonuclear cells, 10% monocytes), slightly elevated total protein (85 mg/dL), normal glucose 60 mg/dL, no bacterial growth and negative India ink for Cryptococcus neoformans. Craniospinal MRI was normal.

Diagnosed as neurosyphilis with HIV/AIDS, he was treated with highly active antiretroviral therapy (HAART), high dosage of intravenous crystalline penicillin, HIV opportunistic infections prophylaxis, pregabalin for neuropathic leg pains and physiotherapy and nutritional support (table 2). Ophthalmological abnormalities resolved after 7 days but lymphadenopathy and wasting syndrome also resolved over 3 months. However, after 8 months of follow-up and being on HAART, tabes dorsalis remained. Repeated HIV viral load at 8 months showed no RNA copies/mL, and CD4 +T cell count increased to 375 cells/µL. The serum VDRL level fell, and the CSF VDRL became negative. The percentage of neurosyphilis patients having pupillary abnormalities ranges from 45% to 53%, although during the course of tabes dorsalis the percentage may be 90%.1–3 A unilateral dilated pupil may be seen in early neurosyphilis, prompting timely diagnosis and treatment, but bilateral tonic pupils can occur later.