Acoustic trauma remains a most important issue in technologically advanced countries. Overexposure to intense sound damages the inner ear sensory cells and can lead to temporary threshold shift (TTS) or permanent threshold shift (PTS) if exposure is sufficiently intense or prolonged. This review includes the recent findings of histological, metabolic, physiological changes after sound exposure and the proposed mechanisms for protection from acoustic injury.
Cats, guinea pigs and mice are widely used as experimental models for hearing research. Recently, mice have been more frequently used because their genomic information and lower degree of inter-animal variability in the response to sound exposure. Overexposure damages the cochlea in two ways, i. e. mechanical and metabolic pathways. In mice, intense exposure (over 116dB SPL 2 hours, 8kHz octave band noise) simultaneously damages the organ of corti and stria vascularis by mostly mechanical pathways. However, sound exposure (112dB SPL 2 hours, 8kHz octave band noise) damaged the organ of Corti within a week by mechanical and metabolic pathways. The first row of outer hair cells is the most vulnerable to sound. Sound exposure (100dB SPL 2 hours, 8kHz octave band noise), which showed damage to only the first row of outer hair cells in histological findings, causes 40dB PTS.
To prevent and protect PTS from sound exposure, some factors or reagents have been identified in animal models, 1) efferent reflex via the olivocochlear bundle (OCB); animals with a large OCB reflex are resistant to sound. 2) conditioning effect; “conditioning” the ear by pre-exposure to a moderate level, non-traumatic sound or heat stress, restraint can dramatically reduce the development of PTS by subsequent sound exposure. 3) Reactive oxygen substances (ROS) scavenger, glutathione; oxidative stress damages the tissue, while ROS scavenger can protect the ear from sound exposure. 4) blocker of glutamate, or neutrophine, 5) steroid. Some reagents have been examined in humans as clinical trial in the US.

抄録全体を表示

A 33-year-old man with Wernicke' encephalopathy due to diet and malnutrition is reported. The patient showed upbeating nystagmus and lateral gaze nystagmus with dizziness and ataxia. Caloric testing demonstrated bilateral canal paresis for horizontal eye movement, but bilateral upbeating nystagmus for vertical eye movement. Optokinetic responses were severely disturbed. Neuro-otological examinations indicated lesions of the cerebellum and brainstem including bilateral vestibular nuclei. Various causes such as alcoholism, hyperemesis gravidarum, hyperalimentation without thiamine, and gastric plication, have been reported in Wernicke' encephalopathy however, this case was considered due to diet and malnutrition, which has rarely been noted. It is necessary to pay close attention to information from the patient regarding nutrition and the pattern of nystagmus in order to diagnose Wernicke' encephalopathy.

抄録全体を表示

The vasovagal reflex is a reflex reaction in which abnormal autonomic system activity may be involved, and it has been known as a cause of dizziness and syncope while standing up. Here, I describe a case of multiple episodes of dizziness and syncope associated with the vasovagal reflex noted in a 6-year-old girl. The patient had repeated episodes of dizziness and syncope while standing up, but no electrocardiographic or organic abnormalities were detected. The active standing test was performed, and the patient was asked to stand up without assistance after being kept at rest for 15 minutes in a supine position. During the test, vital signs and electrocardiographic data were obtained. Dizziness and syncope occurred 14.5 minutes after the patient stood up. At that time, the patient's blood pressure was 86/52mmHg, and heart rate decreased to 44/min. In addition, cardiac arrest was noted for six seconds. A diagnosis of the cardioinhibitory type of the vasovagal reflex was made. The patient is now being treated with α1 stimulator and a tilt training program, exhibiting an uneventful clinical course.

抄録全体を表示

We encountered a rare case of facial nerve paralysis caused by cavernous hemangioma of the facial nerve.
The patient was a 47 year-old man with a chief complaint of food leaking from the left angle of the mouth starting in January 2001. He was diagnosed as having Bell's paralysis, and he was treated with stel-late ganglion block (SGB). However, paralysis did not improve. Furthermore, MRI demonstrated a tumor in the left temporal bone. He was referred to our department on April 17, 2001.
The facial score was 0/40 points by the Yanagihara method. There was no sign of cranial nerves other than the left facial nerve. CT showed a soft tissue shadow in the attic.
Facial nerve schwannoma was suspected, and tympanoplasty was performed on October 16, 2001. The tumor bled easily. A solid tumor about 6mm in diameter was removed en bloc. Pathological diagnosis was a cavernous hemangioma of facial nerve origin.
When we diagnose facial palsy, paralysis due to a tumor should be listed in the differential diagnosis. Imaging is essential for the diagnosis.

抄録全体を表示

We report a case of Hunt syndrome with the primary complaint of lower cranial nerve paralysis. The patient experienced not only lower cranial nerve paralysis, but also, finally, paralysis of the facial nerve. The patient was a 68-year-old woman. She came to the hospital complaining of herpetic vesicles around the right ear and pain, vertigo, and hoarseness, but there was no facial palsy. Hydrocortisore sodium succinate and acyclovir were administered intravenously.
Twelve days after, she developed right facial palsy. Prednisolone and Valaciclovir hydrochloride were orally administered. Fifty Four days after disease onset, the function of all cranial nerves recovered completely.
A review of the Japanese literature revealed 44 cases of Hunt syndrome with multiple cranial nerve palarisis from 1954-2005. In our case, the development of right facial palsy occurred later than all other symptoms. The late-onset facial palsy was only 5 cases and rare.

抄録全体を表示

Although sarcoidosis is a systemic disease, the involvement of the nasal cavity is fairly uncommon. We present a 27-year-old female whose final diagnosis was nasal sarcoidosis. Nasal obstruction was the sole symptom at her first presentation. She underwent deviatomy of the nasal septum and submucosal turbinectomy. The pathological findings suggesting sarcoid granulomatosis indicated a whole body examination. No lesion in the lung, eye and skin was found at that time. Because of her deteriorating nasal lesions such as acute frontal sinusitis and recurrence of the nasal obstruction, she underwent another biopsy about a 18 months after the first surgery. The pathological findings suggested sarcoid granulomatosis and a second whole body examination was performed. The presence of skin, eye and chest lesions in the examinations lead to the final diagnosis of sarcoidosis originating from the nasal cavity. Treatment with local steroids decreased her symptoms. A close follow-up was planned due to the chronic and progressive course of the lesions of her nasal cavity.

抄録全体を表示

A clinical study was performed on 77 patients with parotid tumors who had undergone surgery in the past five years. Benign tumors were observed in 64 patients and malignant tumors in 13 patients. The most common benign tumor was pleomorphic adenoma, followed by Warthin's tumor. Malignant lymphoma was the most common malignant tumor, followed by acinic cell carcinoma and squamous cell carcinoma. The results of preoperative fine-needle aspiration cytology were compared with postoperative pathologic findings. Sensitivity for malignancy was 33.3%, specificity was 100%, and accuracy was 76.5%. Multiple preoperative examinations were necessary to establish the correct diagnosis.

抄録全体を表示

We report a case of renal cell carcinoma metastatic to the tongue. An 82-year-old man presented with a tumor measuring 13×10mm at the right border of the tongue. He had a history of renal cell carcinoma, and had undergone right radical nephrectomy in 1988. He also had multiple metastatic lesions to both lung and brain. He was hospitalized in 2002, and his chief complaint was mastication disorder. In order to improve his quality of life, the tumor of the tongue was resected under local anesthesia, and he could ingest food after the resection. The resected specimen showed renal cell carcinoma. We conclude that if the metastatic tongue lesion is resectable without severe disturbance of function or form, occasional cure can be effected by surgical resection.

抄録全体を表示

Parathyroid cyst is a comparatively rare disease, and it is difficult to differentiate from thyroid cyst preoperatively. Therefore, most patients with parathyroid cyst are definitively diagnosed after surgery. We report four cases of parathyroid cyst. None of these cases was diagnosed as parathyroid cyst preoperatively. Parathyroid cyst is classified into two groups depending on whether the patient demonstrates hyperparathyroidism or not, i. e. functional and nonfunctional. All of our cases were classified as nonfunctional.
It is difficult to distinguish between parathyroid cyst and thyroid cyst by clinical and radiological findings. It has been reported that analysis of cyst contents obtained from puncture under ultrasonography can be a useful technique to diagnose parathyroid cyst correctly. We also suggest a new way to treat the parathyroid cyst less invasively, by puncture and ethanol injection.

抄録全体を表示

¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is a powerful tool for the detection of malignant tumors. We herein reported a case of cervical metastasis from unknown primary. Primary tumor was successfully diagnosed by FDG-PET. A 70-year-old man presented with a right-sided cervical lymph node swelling. Fine needle aspiration cytology in the previous hospital showed class III atypia, however, the primary tumor was not found by physical examination, fiberscopy, computed tomography (CT), or magnetic resonance imaging. Open biopsy of the neck demonstrated that the lesion was metastatic squamous cell carcinoma, and he subsequently underwent neck dissection on the affected side. FDG-PET and PET/CT after surgery revealed demonstrated uptake in the right piriform recess of the hypopharynx. The patient was eventually referred to our department, and underwent biopsy of the piriform recess via direct endoscopy. Histopathological diagnosis was the poorly-differentiated squamous cell carcinoma, and then he received radical radiotherapy of 72Gy to the whole neck. There was no evidence of recurrence on FDG-PET performed four months after radiation. The literature on the clinical usefulness of FDG-PET for the diagnosis of head and neck cancers were reviewed.

抄録全体を表示

We experienced a case of dyspnea caused by deep cervical hematoma following stellate ganglion block (SGB). A 79-year-old male underwent SGB due to headache caused by herpes zoster of the trigeminal nerve. He developed dyspnea three hours after SGB, and consulted our hospital. CT revealed a deep cervical hematoma of the retropharyngeal space. After intubation, he was operated on emergently under general anesthesia and the hematoma was removed. Two days after the operation, the hematoma was relieved, and so he underwent decannulation. After the decannulation, dyspnea was resolved.
Cervical hematoma following SGB is rare, but a life-threatening complication. And so we believe patients should be admitted when they underwent SGB.
After hematoma formation, when the airway is maintained by intubation or tracheotomy, hematoma removal should be undergone if there are sufficient staff with adequire skills, because we can expect that patients recover quickly and therefore have a short hospital stay.

抄録全体を表示

The transplantation of hematopoietic stem cells (HSCs) is regarded to be a potential approach for promoting the repair of damaged organs. Here, we investigated the influence of hematopoietic stem cells on progressive hair cell degeneration after cochlear ischemia in gerbils. Intrascalar injection of HSCs prevented Ischemia-induced hair cell degeneration and ameliorated hearing impairment. The administration of HSCs apparently augmented the upregulation of ischemia-induced GDNF, which is proved to inhibit ischemic cochlear damage. A tracking study revealed that HSCs injected into cochlear were retained in the perilymphatic space of the cochlea, although they neither transdifferentiated into cochlear cell types nor fused with injured hair cells. These results suggested that HSCs have therapeutic potential by preventing ischemia-induced hearing loss, probably through their paracrine effects. We concluded that the direct administration of HSCs into the perilymphatic space can be a new therapeutic strategy for sudden-onset hearing loss due to cochlear ischemia.

抄録全体を表示