Idiopathic myelitis presenting as Brown-Séquard syndrome: two case reports and a review of the literature

Background Brown-Séquard syndrome often occurs in spinal cord injury, and few myelitis patients present with Brown-Séquard syndrome. Case presentation A 33-year-old Han man was admitted with neck pain plus numbness in the right limbs for 2 days and weakness in the left limbs for 1 day. Examination was significant for left limbs with grade 4 muscle power, positive left Babinski sign, diminished vibration sensation in the left limbs and decreased pain below the right clavicle dermatome. The cerebrospinal fluid (CSF) cell count was 24 × 10 6 /L, and the protein count was 185 mg/L. Cervical magnetic resonance imaging (MRI) indicated abnormal swelling signals in the medulla-cervical cord long segment and enhanced signals in the C2-3 region. In the second case, a 47-year-old Han woman was admitted with weakness in the right lower limb and numbness in the left lower limb for more than 20 days. Examination was significant for the right lower limb with grade 4 muscle power, left knee hyperreflexia, positive left Babinski sign, diminished vibration sensation in the right lower limb and decreased pain below the right T2 dermatome. Cervical MRI indicated hyperintense and enhanced signals in the C7-T2 region. In these two cases, CSF culture, oligoclonal band (OB) and aquaporin 4 (AQP4) antibody were negative. Brain MRI was normal. Their symptoms and MRI results improved after treatment with methylprednisolone. Conclusions Myelitis can present as Brown-Séquard syndrome, providing an extended reference in terms of the differential diagnosis for clinical physicians.