Masaichi Nakamura

Auditory Nerve Disease of Both Ears Revealed by Auditory Brainstem Responses, Electrocochleography and Otoacoustic Emissions

We report on two patients who showed absence of auditory brainstem response (ABR) but broad compound action potentials on electrocochleograms and almost normal otoacoustic emissions, together with absence of caloric response and preservation of per rotatory nystagmus for both ears. Patient 1, a 53-year-old woman, had noted auditory and vestibular problems since the age of 15 years, and Patient 2, a 68-year-old woman, had noted problems of the same age of 30 years. They could hear words and understand sentences if spoken slowly, but they could not discriminate monosyllables very well. Their auditory examinations disclosed mild threshold elevation in pure-tone audiometry and markedly poor scores in speech audiometry and good scores in auditory comprehension test. They were diagnosed as having auditory nerve disease of unknown cause.

Auditory Findings in Patients with Maternally Inherited Diabetes and Deafness Harboring a Point Mutation in the Mitochondrial Transfer RNALeu (UUR) Gene

Five patients with sensorineural hearing loss, who harbored a point mutation in the mitochondrial transfer RNA (tRNA) gene tRNALeu (UUR), from five unrelated family pedigrees were examined. In these families diabetes and deafness were maternally inherited. Bilateral hearing was more severely impaired at higher frequencies. Audiometric test results revealed that hearing loss involved the cochlea. Hearing gradually deteriorated; the progression rate ranged from 1.5 to 7.9 dB per year. Proportion of mutant mitochondrial DNAs (mtDNAs) in the leukocytes was not related to the rate or degree of hearing loss, although hearing loss appeared at a younger age in patients with higher heteroplasmy. We speculate that after the proportion of damaged mtDNAs, mostly as a result of mutation, exceeds the expression threshold for deficiencies in mitochondrial protein synthesis and oxygen consumption, a drop in adenosine triphosphate level could lead to an imbalance of ion concentration, resulting in cell death in the cochlea.

Cervical vertebral osteomyelitis revisited: A case of retropharyngeal abscess and progressive muscle weakness:

Vertebral osteomyelitis is a relatively rare condition and comprises 2% to 7% of all hematogenous bone infections; furthermore, only 6.5% are located in the cervical region.1 The mortality rate ranged from 25% to 71% before the antibiotic era.2 The use of antibiotics has decreased the rate, but the incidence of pyogenic vertebral osteomyelitis in recent years appears to have increased.1 Because of its insidious and sometimes bizarre clinical presentation, there is usually a considerable delay in diagnosing pyogenic osteomyelitis. This delay is even longer when vertebral osteomyelitis is complicated by neurologic involvement. Few cases with this bizarre presentation associated with retropharyngeal abscess have been reported. In this article we describe a case initially diagnosed as a retropharyngeal abscess that proved to be cervical vertebral osteomyelitis. CASE REPORT

Metastatic hypopharyngeal carcinoma to the temporal bone.

Two cases of temporal bone metastasis by hypopharyngeal carcinomas are reported. One patient was a 43-year-old Japanese male who developed palsy of left oculomotor, trochlear, trigeminal, abducens and facial nerves. Carcinoma infiltrated the petrous portion of the left temporal bone. Tumor had destroyed a part of the facial canal and invading tumor cells were in contact with the perineurium. The other patient was a 59-year-old male who had no obvious facial nerve or otologic symptoms during the clinical course of his disease. Postmortem findings showed that carcinoma had invaded the right temporal bone and had produced extensive destruction of the facial canal. Degenerative findings were evident in the nerve. In the cases presented here, tumor resulted either from metastatic lymph nodes or had invaded through the suture of the temporal and sphenoid bones around the foramen lacerum to the middle cranial fossa and then infiltrated the temporal bone.

Pleomorphic Adenoma of Submandibular Gland.

Five patients were treated for pleomorphic adenoma of the submandibular gland: 2 males and 3 females, aged 24 to 53 years. The tumors were on the right side in 3 cases, on the left in 2. All 5 patients complained of a painless mass in the submandibular lesion. Ultrasound sonography and CT scan were useful in the diagnosis In 3 patients Ga scintigraphy showed abnormal accumulation although the histopathological diagnosis was benign tumor. It was presumed that the proliferating activity is higher in pleomorphic adenomas of the submandibular gland than in those of the parotid gland. All patients were treated surgically.