Case report

A 42-year-old right-handed African–American woman had been diagnosed with AIDS 11 years before the abrupt onset of numbness and heaviness in her left lower limb. On presentation, her absolute CD4 cell count was 72/mm³ (430–1690) and HIV-1 viral load was 14,972 copies/mm³ (lower detection limit 40) due to antiretroviral non-adherence. Within 24 hours of presentation, the weakness and loss of sensation had spread to her right lower limb. There was no history of preceding trauma or features of infection. She was evaluated at an outside hospital where she was noted to have marked weakness and areflexia in her lower limbs. A spinal cord MRI with gadolinium demonstrated a longitudinally extensive intramedullary lesion with corresponding enhancement at the T3–T5 levels and oedema (figure 1A, B). Cerebrospinal fluid (CSF) analysis (table 1, LP#1) and an extensive workup for causes of transverse myelitis (Table 2) were unrevealing. The initial diagnosis was of idiopathic transverse myelitis. Following 5 days of intravenous methylprednisolone, there was mild strength improvement in her right lower limb. She was discharged to a rehabilitation facility, but returned to the outside hospital 1 week later due to worsening bilateral lower limb weakness. A repeat spinal cord MRI scan showed similar findings to her original study. MRI scan of the brain with gadolinium showed an area of hyperintensity on the fluid-attenuated inversion recovery (FLAIR) sequences in the subcortical white matter of the superior right temporal lobe, with corresponding enhancement on T1 postcontrast sequences (figure 1C–E).