Prominent brainstem symptoms/signs in patients with neuromyelitis optica in a Taiwanese population

Neuromyelitis optica (NMO) is a severe demyelinating disease defined principally by its selective effect on the optic nerves and spinal cord. Contemporary diagnostic criteria require an absence of any clinical disease outside the optic nerve or spinal cord. However, we frequently encounter patients with NMO who have previously undetected symptomatic brainstem lesions. We investigated the brainstem symptoms/signs in patients with NMO and their corresponding MRI findings in a Taiwanese population. We evaluated the clinical symptoms/signs, anti-aquaporin-4 antibody titer and corresponding brain MRI of 49 patients with NMO; results were obtained from chart reviews and during clinical visits. A total of 18 (37%) patients with NMO had brainstem symptoms/signs, including diplopia (n=9, 50%), prolonged hiccup and poor appetite (n=9, 50%). For these patients, most of their brainstem events occurred during the first demyelinating attack in their NMO course. A higher percentage (77.8%) of patients with brainstem NMO had brain lesions with specific NMO patterns, including lesions involving the hypothalamus (n=6, 33.3%), midbrain or pons (n=8, 44.4%), periaqueductal regions (n=5, 27.7%), and medulla (n=10, 55.6%). Brainstem symptoms/signs and characteristic NMO imaging findings are common in Taiwanese patients with NMO, and should be considered a part of the illness in addition to optic neuritis and myelitis.