Abstract
Moyamoya disease can be associated with autoimmune disease such as thyrotoxicosis, but there has been only one report of association with neuromyelitis optica (NMO). We report another case of this combination with the presence of anti-SSA antibody in addition to the NMO-immunoglobulin G. The patient presented limb weakness along with unsteady gait and numbness. A magnetic resonance imaging (MRI) of the spine showed extensive intramedullary hyperintense signals at C2 to T3 levels. On the other hand, no lesions were found on the MRI of the brain. The patient tested positive for anti-aquaporin-4 antibody and anti-SSA antibody which confirms the diagnosis of NMO. A magnetic resonance angiography scan of the brain revealed a bilateral distal occlusion of the internal carotid arteries (ICAs) as well as occlusions of the middle cerebral arteries (MCAs) with fine collaterals in the region which confirms the diagnosis of moyamoya disease. This report suggests that autoimmunity may be an important factor in the pathogenesis of moyamoya disease in some patients.