Neurosyphilis presenting with myelitis-Case series and literature review

Abstract Background Neurosyphilis is a great imitator because of its various clinical symptoms. Syphilitic myelitis is extremely rare manifestation of neurosyphilis and often misdiagnosed. However, a small amount of literature in the past described its clinical manifestations and imaging features, and there was no relevant data on the prognosis, especially the long-term prognosis. In this paper, 4 syphilis myelitis patients admitted to our hospital between July 2012 and July 2017 were retrospectively reviewed. In the 4 patients, 2 were females, and 2 were males. We present our experiences with syphilitic myelitis, discuss the characteristics, treatment and prognosis. Case presentation The diagnosis criteria were applied: (1) diagnosis of myelitis established by two experienced neurologist based on symptoms and longitudinally extensive transverse myelitis (LETM) at the cervical and thoracic levels mimicked neuromyelitis optic (NMO) on magnetic resonance imaging (MRI) ; (2) Neurosyphilis (NS) was diagnosed by positive treponema pallidum particle assay (TPPA) and toluidine red untreated serum test (TRUST) in the serum and CSF; (3) negative human immunodeficiency virus (HIV). Likewise, all patients were negative for serum anti-aquaporin 4 (AQP-4), as well as negative bacterial, fungal, virus, or mycobacterium tuberculosis in the CSF. Treatment included intravenous penicillin G, with 24 million units of penicillin G per day administered intravenously for 14 days, and three patients were also treated with systemic corticosteroids. Neurological examination, serologic syphilis diagnostic tests (TPPA, TRUST) and cerebrospinal fluid tests (TPPA, TRUST) were examined approximately every 12~24 weeks after treatment. The follow-up time ranged from 12 to 70 months, with an average of 36.6 months. The prognosis was well in 3 cases who received early anti-syphilis treatment, but 1 case who received delayed treatment due to misdiagnose had no improvement. Conclusions Neurosyphilis should be considered when there are long hyperintensity lesions in the MRI spinal cord. Prompt diagnosis and combined antibiotics-corticosteroid therapy may improve neurological prognosis.