The role of anti-aquaporin 4 antibody in the conversion of acute brainstem syndrome to neuromyelitis optica.

BACKGROUND: Acute brainstem syndrome (ABS) may herald multiple sclerosis (MS), neuromyelitis optica (NMO), or occur as an isolated syndrome. The aquaporin 4 (AQP4)-specific serum autoantibody, NMO-IgG, is a biomarker for NMO. However, the role of anti-AQP4 antibody in the conversion of ABS to NMO is unclear. METHODS: Thirty-one patients with first-event ABS were divided into two groups according to the presence of anti-AQP4 antibodies, their clinical features and outcomes were retrospectively analyzed. RESULTS: Fourteen of 31 patients (45.16 %) were seropositive for NMO-IgG. The 71.43 % of anti-AQP4 (+) ABS patients converted to NMO, while only 11.76 % of anti-AQP4 (-) ABS patients progressed to NMO. Anti-AQP4 (+) ABS patients demonstrated a higher IgG index (0.68 ± 0.43 vs 0.42 ± 0.13, p < 0.01) and Kurtzke Expanded Disability Status Scale (4.64 ± 0.93 vs 2.56 ± 0.81, p < 0.01) than anti-AQP4 (-) ABS patients. Area postrema clinical brainstem symptoms occurred more frequently in anti-AQP4 (+) ABS patients than those in anti-AQP4 (-) ABS patients (71.43 % vs 17.65 %, p = 0.004). In examination of magnetic resonance imaging (MRI), the 78.57 % of anti-AQP4 (+) ABS patients had medulla-predominant involvements in the sagittal view and dorsal-predominant involvements in the axial view. CONCLUSIONS: ABS represents an inaugural or limited form of NMO in a high proportion of anti-AQP4 (+) patients.

Brain stem infarction associated with familial Mediterranean fever and central nervous system vasculitis.

Familial Mediterranean fever (FMF) is an autoinflammatory autosomal recessive disease caused by mutations of the Mediterranean fever (MEFV) gene on chromosome 16p. Clinically, it is characterized by recurrent episodes of fever and painful polyserositis. An association of FMF with systemic vasculitis, namely Henoch-Schönlein purpura, polyarteritis nodosa and Behçet's disease has been described. Neurological manifestations of FMF occur rarely and include demyelinating (MS-like) lesions, posterior reversible encephalopathy syndrome, and pseudotumour cerebri. Hitherto hardly known, we herein present a young patient with a genetically proven FMF who suffered a brain stem infarction during a typical FMF attack. After a careful diagnostic workup including cerebrospinal fluid analysis, intra-arterial angiography and leptomeningeal biopsy, a FMF-associated central nervous system vasculitis was identified as the cause of stroke. The pathophysiological background and potential therapeutic strategies are discussed.