Intractable hiccup caused by medulla oblongata lesions: a study of an autopsy patient with possible neuromyelitis optica.

We report the first autopsy verification of medulla oblongata lesions involving bilateral nucleus tractus solitarius (NTS) as a cause of intractable hiccup in an autopsy patient. The female patient first developed pain and weakness in the lower limbs and urinary incontinence at age 48, and was given a diagnosis of myelitis. Intractable hiccup was accompanied by urinary retention on the third attack. She died of respiratory failure when the fifth attack occurred at age 51. Autopsy disclosed severe involvement of the medulla oblongata and entire spinal cord. Optic nerve lesions were also identified unexpectedly. Dual involvement of the optic nerve and spinal cord, necrotic spinal cord lesions involving not only myelin but also neurons and axon, and marked extension of the spinal cord lesions in both the longitudinal and transverse directions suggested the diagnosis of neuromyelitis optica rather than multiple sclerosis. Although animal experiments have shown that NTS is a critical structure in the hiccup reflex, we demonstrated for the first time the involvement of the NTS in an autopsy patient with intractable hiccup.