Hideaki Sakata

Pathological findings in the temporal bone of newborn infants with neonatal asphyxia.

Conclusions Hypoxia in adults frequently causes damage to the brain, but not the inner ear. However, hypoxia in neonates with inadequate blood–inner ear barrier function causes damage to the inner ear, leading to hearing loss and equilibration disorder. Objective Clinically, asphyxiated neonates sometimes have the complication of sensorineural hearing impairment at high frequencies. Many reports suggest that this problem is caused by hypoxic encephalopathy. However, it is not clear whether inner ear disorders are present. In this report we examined the inner ear pathology of four asphyxiated neonates using serial sections of temporal bone. Material and methods The subjects (n=4) were 1–13-day-old neonates with pregnancy periods of 24–36 weeks. Their fetal growth curves were within the normal range. There was one case each of twin pregnancy, placental abruption, placenta previa and meconium aspiration syndrome. Results For the case of severe neonatal asphyxia, damage to the inner ear included the degeneration and disappearance of outer hair cells of the organ of Corti and edematous changes in the stria vascularis. Degeneration of spiral ganglion and vestibular ganglion cells was observed in two of the other cases.

Etiology and one-year follow-up results of hearing loss identified by screening of newborn hearing in Japan

Objective: To evaluate the incidence of newborn hearing loss in a Japanese population and to elucidate etiological factors and one-year prognosis. Study Design: Screening of newborn hearing. Setting: Childrens tertiary referral center. Subjects and Methods: Between 1999 and 2008, 101,912 newborn infants were screened, with 693 infants (0.68%) referred. Etiology investigation included CT, detection of cytomegalovirus (CMV) DNA, and connexin 26 mutation. Results: Abnormal results (auditory brainstem response [ABR] threshold ≥ 35 normal hearing level [dB nHL] in either side) were observed in 312 infants (0.31%), and 133 subjects (0.13%) with ABR thresholds ≥ 50 dB nHL on both sides were classified into the habilitation group. In this group, inner ear/internal auditory meatus anomalies were detected in 20 of 121 subjects (17%) tested, middle/external ear anomalies in 14 of 121 subjects (12%), CMV DNA in 13 of 77 subjects (17%), and connexin 26 mutation in 28 of 89 subjects (31%). In 68 subjects undergoing all three investigations (CT, CMV, and connexin 26), 41 (60%) had positive results in at least one test. With inclusion of otitis media with effusion and perinatal problems, this rate amounted to 78% (53 subjects). Of the 97 infants in the habilitation group successfully followed up to one year, 36 (37%) showed a threshold change of 20 dB or more in either ear: 11 (11%) progression and 25 (26%) improvement, and 15 infants (15%) were reclassified into a less severe classification. Conclusion: Considering that 26 percent of infants with bilateral moderate to severe hearing loss showed improvement in one year, habilitation protocols, especially very early cochlear implantation within one year of birth, should be reconsidered.

Cisplatin-induced Hearing Loss: The Need for a Long- term Evaluating System

Cisplatin is an effective chemotherapeutic agent against pediatric cancers; however, ototoxicity is a concern. This study describes the frequency, severity, and clinical course of hearing loss in Japanese pediatric patients treated with cisplatin-based multimodal therapy. A total of 55 children who received cisplatin-based therapy from 1983 to 2012 underwent audiologic evaluations. Data were analyzed to determine the onset, time-to-progression, and severity of hearing loss. Thirty-five patients, 12 of 16 older patients (4 y or older), and 23 of 39 younger patients (under 4 y), including 7 of 8 patients treated with cisplatin, carboplatin, and radiotherapy, developed hearing loss. Ten of 18 patients who received a cumulative cisplatin dose of <360 mg/m2 developed hearing loss at a minimum dose of 200 mg/m2. Median time to onset after the last cisplatin dose was 71 days; 6 patients developed hearing loss after ≥2 years. Four patients required hearing aids, 6 patients developed progressive hearing loss with time, and 4 patients exhibited persistent hearing failure at low frequencies. Risk factors for acquired hearing loss and its severity may be associated with a combination of factors such as cisplatin and carboplatin therapy, radiotherapy, age at diagnosis, and genetic background. Our results suggested that all pediatric patients treated with cisplatin would have their hearing evaluated regularly, irrespective of the cumulative cisplatin dose as a suggestion, and that further prospective studies regarding ototoxicity including genetic polymorphisms analysis were required.

Papillary Carcinoma of the Thyroid Originating in a Thyroglossal Cyst

A 34-year-old female with papillary carcinoma of the thyroid originating in a thyroglossal cyst is described. The patient’s chief complaint was a submental mass. The mass was 6 × 4 cm, elastic, soft, and smooth-surfaced. CT examination showed high-density areas in part of the interior of the mass. Resection of the mass was attempted with a diagnosis of thyroglossal cyst. Since papillary carcinoma of the thyroid was noted in the cyst by intraoperative frozen section pathological examination, primary carcinoma of the thyroid was suspected, and the thyroid and surrounding areas were examined. Since no abnormalities were noted in the thyroid, the thyroid was preserved. According to the following reasons, the tumor was considered to be primary papillary carcinoma of the thyroid arising in the thyroglossal cyst: (1) Scar formation was noted in the center of the tumor; (2) tumor cells partly infiltrated into the surrounding tissues, and (3) no tumor was noted in the thyroid. A definitive diagnosis of carcinoma arising in the thyroglossal cyst has required confirmation of the absence of carcinoma in the thyroid by total thyroidectomy. In the present case, however, total thyroidectomy was avoided, because no gross pathological changes were observed in the thyroid during the operation. This decision may be controversial both diagnostically and therapeutically, but we consider from our observation of the course that total thyroidectomy is not always necessary.

Risk factors for hearing loss after pediatric meningitis in Japan.

Objectives We sought to identify predictors for hearing loss in Japanese children with meningitis. Methods We analyzed 155 cases of pediatric meningitis without other entities causing hearing loss in children admitted to Saitama Childrens Medical Center between 1990 and 2005 for potential risk factors for hearing loss, using multiple logistic regression. Auditory brain stem response tests were performed to evaluate hearing loss. Results Of 155 children, 35 (23%) developed hearing loss (21 unilaterally and 14 bilaterally). Profound hearing loss (greater than 90 dB normal hearing level) occurred in 15 patients (9.7%; 4 unilaterally and 11 bilaterally). Of 112 patients with positive cerebrospinal fluid cultures, 27 (24%) developed hearing loss and 13 (12%) showed profound loss. Of 22 patients with Streptococcus pneumoniae meningitis, 11 (50%) developed hearing loss and 7 (32%) showed profound loss. Of 54 patients with Haemophilus influenzae meningitis, 11 (20%) developed hearing loss and 4 (7.4%) showed profound loss. High serum C-reactive protein levels and cerebrospinal fluid cultures positive for Streptococcus pneumoniae were identified as significant risk factors for hearing loss. Conclusions A high serum C-reactive protein level was first identified as a risk factor for hearing impairment after pediatric meningitis.

Auditory Brainstem Response and Temporal Bone and Brainstem Pathology in Brainstem Death, with Special Reference to Autolysis of Red Blood Cells

We studied the pathological changes in the temporal bone and brainstem, with particular attention to the autolysis of red blood cells in and around the blood vessels, in six cases of brainstem death determined by auditory brainstem responses (ABRs). Our findings showed that the cochlea, the visceral organs and the spinal cord below a certain level of the cervical segments continued to live after brainstem death. Red blood cells in the vessels of the brainstem and cerebellum exhibited severe autolysis, whereas most red blood cells in the cochlea were preserved. Our findings of autolytic changes in red blood cells in the brainstem, and the preservation of red blood cells in the cochlea, imply initial loss of brainstem function and delayed loss of cochlear function after prolonged absence of ABRs.

Auditory brainstem response and temporal bone pathology findings in a brain-dead infant

The criteria for assessing adult brain death have been already established, but those for infant brain death have not been yet established in Japan. We report auditory brainstem response (ABR) and postmortem pathology of the temporal bone and brain of a brain-dead 9-month-old female. During the comatose state, her ABR showed only waves I and II bilaterally. Autopsy revealed the presence of a left cerebellar astrocytoma, herniation and anoxic encephalopathy. The pathological examination of the temporal bone revealed the destruction of the inner ear particularly on the left side. In the auditory pathway of brain-dead patients, degeneration occurs first in the cerebrum, followed by the cochlear nerve. Thus, ABR is one of the useful means to assess brain death even in infants.

Head and neck tumors in children experienced in our department—mainly neck tumors

laryngeal papilloma (3), tongue papilloma (3) and fibromatosis (2). We also had one case each of calcifying epithelioma, angiofibroma, histiocytosis X, glioma, neurilemmoma, osteoma and teratoma. The eight malignant tumors consisted of four rhabdomyosarcomas, two metastatic neuroblastomas, one metastatic congenital leukemia lesion and one mucoepidermoid carcinoma of the larynx. Among the children with hemangiomas, one quarter showed subglottic space involvement. Two thirds of the lymphangiomas were located in the neck region and half of the hamartomas were located in the midline of the tongue. The symptom onset for these tumors ranged 0 days to 13 years 4 months, and nearly half of the cases had manifestations at birth. It is noteworthy that none of the patients with subglottic hemangiomas had symptoms at birth despite the congenital nature of their disorders, which did not become evident until l-2 months of age.

Low-Tone Sensorineural Hearing Loss. Therapeutic Effectiveness and Long-term Recuperation.

We often see patients with low-tone sensorineural hearing loss who complain more of a sense of ear fullness than of hearing loss. The cause has not yet been identified but endolymphatic hydrops seems to be the most probable etiology. We studied the effectiveness of therapy of low-tone sensorineural hearing loss.The disease frequently occurs in women aged 20 to 50. The therapeutic success rate is high (71%) and the average until remission is 5.8 days ; the longest was 22 days. But the rate of recurrence was as high as (40.2%). We gave patients various drugs and performed stellate ganglion block. No significant difference was found among the drugs or between drug therapy and stellate ganglion block.We used transtympanic injection of steroid to treat patients with recurrence or intractable disease. Such therapy (steroid targetting therapy) had some effect.