Otogenic Brain Abscess Presenting with Gait Ataxia
A 67 year old male patient was admitted to the emergency room with dizziness and gait ataxia that had suddenly developed two days previously. The patient was receiving pharmacological treatment for hypertension and diabetes and there was no relevant family history. Other than the dizziness and gait ataxia, the patient complaining of headache, hearing loss and aural pressure in the left ear, and aural discharge but these did not accompany otalgia or tinnitus. The patient displayed a clear state of consciousness in neurological examination, his papillary reflex was normal, and nystagmus was not observed. The patient fell toward left even with his eyes open in the Romberg test and displayed dysmetria on the left side in the cerebellar function finger to nose test. Brain CT taken in the emergency room displayed the formation of a common wall, including the wall that enhanced the contrast in a circle of 5×5 cm toward the left cerebellum and a manifestation in which it pressed the brain stem and the fourth ventricle (). With the suspicion of brain abscess in the left cerebellum, the patient was admitted to the neurosurgical ward and received antibiotic treatment. Two days after he was admitted to hospital, his state of consciousness suddenly altered to drowsy and craniotomy and drainage of abscess was performed in response. As a result of requesting department of otorhinolaryngology for phy-sical examination in order to assess the causative diseases after surgery, it was found that the external auditory canal was narrow and aural discharge and granulation tissue were observed in the left ear. The right ear was normal. Tympanic mem-brane retraction and the aural discharge that accompanies keratin were also observed ().\nOn temporal bone CT taken with the suspicion of left otitis media cholesteatomatica, an overall destruction of the cochlea and vestibular organ in the left ear caused by cholesteatoma was indicated (). Air conduction hearing and bone conduction hearing of 36 dB respectively was presented for the right ear and hearing loss was found in the left ear when performing pure tone audiometry. The degree of paralysis in the left semicircular duct was 100% on the results of a caloric test using air. Under diagnosis of otitis media cholesteatomatica, which causes cerebellar abscess with overall invasion of labyrinth and intracranial expansion, cholesteatoma and granulation tissue were removed through transotic approach (). The surgery was performed a month after performing drainage of the abscess in neurosurgery. As the granulation tissue including keratin had infiltrated the mastoid antrum, auris media, and vestibular labyrinth and had destructed the bone structure, it was difficult to pinpoint the landmark that is seen during tympanomastoidectomy. Although the abscess was discharged within the cochlea, there was invasion into the internal acoustic canal. The junction between the mastoid antrum and posterior fossa was cut after connecting with fibrous tissue and there was no outflow of cerebrospinal fluid. As partial outflow of cerebrospinal fluid was found in the internal acoustic canal, this was stopped with soft tissue and the surgery was finished after filling the deletion by sampling fatty tissue from the stomach. As a result of assessing the bacterial culture from the abscess that was displayed in the mastoid antrum during surgery, group D enterococcus was cultivated and the result for acid-fast bacilli culture was negative. The patient was discharged from the hospital after recovery without neurological sequela and is currently under observation through follow-up CT without relapse ().