Central sleep apnea (CSA) is characterized by the cessation of air flow without respiratory effort during sleep. Various neurological diseases have been shown to be associated with CSA. In this case, we report a 37-year-old male with who admitted to us for sleep respiratory disturbance. CSA was diagnosed after a full-night polysomnography. Although the neurological examination of the patient was normal, we detected hyperintense brain lesions in magnetic resonance imaging (MRI), past history for optic neuritis and delayed visual evoked potential responses on the left eye and diagnosed as clinically isolated syndrome (CIS) accompanying to CSA. These findings show and emphasize the importance of MRI in patients with CSA even their neurological examination is normal. Up to our knowledge, this is the first case of CSA reported in a patient with CIS.