小脳膿瘍の原因となった真珠腫性中耳炎例 A Case of Cholesteatoma Causing a Cerebellar Abscess

A case of bilateral cholesteatomas which caused a cerebellar abscess is reported herein. The patient was a 38-year-old male who had bilateral otorrhea and hearing loss from childhood. He presented with fever, a headache, and vertigo which had started in the summer, and he visited our hospital 2 months later because the symptoms did not improve. At the first visit, nystagmus was not present. CT images revealed bilateral cholesteatomas, and there was a lateral semicircular canal fistula with expansion of the cochlea and the posterior semicircular canal in the right ear. There was no bone defect of the middle- and post-cranial fossa. At first, we regarded the vertigo as peripheral, and planned a radical operation on the right middle ear. But, after hospitalization, the patient collapsed with a tendency to somnolence and Bruns' nystagmus. MRI revealed an abscess in the right cerebellar hemisphere. To treat obstructive hydrocephalus and the cerebellar abscess, trepanning ventricular drainage and brain abscess drainage via a craniotomy were carried out. After treatment with antibiotics, the patient's general state improved. Accordingly, a mastoidectomy with labyrinthectomy was performed on the right ear, and a staged tympanoplasty was carried out on the left ear. There has been no recurrence for 3 years until the time of writing. We presume that the infection route of this case was the internal auditory meatus. A cerebellar abscess secondary to cholesteatoma is rare, but early examination and treatment are necessary, because the fatality rate in these cases is higher when a brain, especially cerebellar abscess occurs.