Vol.100 No.8 contentsPRACTICA OTO-RHINO-LARYNGOLOGICA
Vol. 100 No. 8 August 2007
Brainstem Medulloblastoma Manifesting as
Low-tone Sensorineural Hearing Loss
Hitoshi Satoh, Toshiyuki Fujisaki, Tadashi Wada,
Yamato Kubota, Shuji Izumi and Sugata Takahashi
(Niigata University, School of Medicine)
Medulloblastoma is the most common childhood primary central nervous system tumor. In adults, most medulloblastomas occur in patients younger than 40. Common symptoms are cerebellar dysfunction and signs of CSF flow obstruction.
This report describes the case of a 25-year-old female who presented with progressive unilateral sensorineural hearing loss (SNHL) as the first symptom of a medulloblastoma in the right inferior cerebellar peduncle and pons. She was referred to an ENT outpatient clinic, and diagnosed with right low tone-dominant SNHL. Her right SNHL progressed with an additional symptom, left moderate facial palsy, 7 months later, and she consequently visited the clinic again. She was introduced to our clinic for further examination. At that time, magnetic resonance imaging (MRI) revealed a right brainstem lesion. The ipsilateral stapedial reflex was normal in the right ear but absent in the left. Bekesy audiometry was type III. Electronystagmography showed a spontaneous nystagmus to the left and saccade pursuit. The auditory brainstem response was absent in the right ear.
The presented case showed that unilateral SNHL can be the first symptom of a brainstem tumor lesion. Progressive SNHL cases should be checked by MRI, in order to exclude brainstem lesions just like cerebello-pontine angle lesions.
Key words : medulloblastoma, sensorineural hearing loss, MRI