We present a Japanese patient with genetically confirmed juvenile-onset AxD. Episodic vomiting, which was the only sign of bulbar dysfunction, caused malnutrition and weight loss, probably related to a tiny lesion seen by MRI in dorsal part of medulla oblongata, presumably involving the “area postrema”, which plays an essential role in the system controlling feeding [6]. Similar cases have already been reported [7, 8], but the patients in the literature also had additional bulbar symptoms, such as dysphagia and dysphonia. This case indicates that a molecular analysis of the GFAP gene is warranted in patients with MRI evidence of even tiny tumor-like lesions in the brainstem, particularly if they present with isolated episodic vomiting and/or anorexia.