Motohisa Ikeda

A CT Study of the Course of Growth of the Maxillary Sinus: Normal Subjects and Subjects with Chronic Sinusitis

We measured the maxillary sinus volume of normal children and those with bilateral chronic sinusitis by coronal CT scan of the paranasal sinus, and compared the results with findings previously obtained from adult patients. The distribution of mean maxillary sinus volume by age group from 4–9 to 70–79 years exhibited a monomodal pattern with a peak in the 20s in both the normal group and the surgical therapy group. The maxillary sinus volumes of children aged 10–15 years and adults tended to be smaller in the surgical therapy group than in the normal group; this tendency was more prominent in the adult group. These findings appear to support the hypothesis that the ethmoid infundibulum and middle meatus are narrowed by inflammation of the ostiomeatal complex and by various bony anatomic variations in the nasal cavity, leading to impaired pneumatization of the maxillary sinus.

Evaluation of Hyperactive Caloric Responses in Patients with Inner Ear Diseases

Twenty-three patients with various types of inner ear diseases, who showed hyperactive caloric responses (21 patients showed unilateral hyperactive caloric responses, and 2 patients showed bilateral hyperactive caloric responses) were monitored during 2-10 years and underwent caloric tests repeatedly (2-7 times). None of them showed continuous hyperactivity of the labyrinth throughout their clinical courses. It seems that hyperactive caloric responses in patients who suffer from inner ear disease may be a transient phenomenon, caused by fluctuations of the vestibular condition, central compensation, age and/or mental state of the patients.

A Case Report of Occult Thyroglossal Duct Carcinoma

A 50-year-old male had an occult thyroglossal duct carcinoma in the thyroglossal duct remnant attached to the upper pole of a thyroglossal duct cyst which was noticed due to extravasation of the cyst. After the patient had been struck into the thyroid cartilage with the tip of a bamboo sword while practicing Japanese fencing. The authors emphasize again that the important matter in the treatment of thyroglossal duct cysts is the removal of the whole thyroglossal duct remnant with the central portion of the hyoid bone according to Sistrunks method in order to prevent not only recurrence of the thyroglossal duct cyst but also not to overlook any microcarcinoma.

Electronystagmography outside the hospital using a pocket-sized electrocardiograph.

It is the desire of the neurotologic clinician to record routinely the nystagmus of patients with vestibular disorders but it is troublesome to have it done frequently. We tried to have patients record their own nystagmus using a portable electrocardiograph. It is pocket-sized and can be operated easily at any time and any place by laymen and often provides beneficial information. When we performed the caloric test on nine patients, we recorded the nystagmus with an ordinary electronystagmograph and with this equipment simultaneously. It has been recognized that the records with a portable electrocardiograph bear close resemblance to the records obtained with an ordinary electronystagmograph. According to the experience in twenty cases of dizzy patients using this recording system, it was concluded that the equipment is useful not only for the diagnosis of dizzy patients, but also for evaluating the effect of drugs and for recommending changes in the mode of living for some patients.

Hearing Levels in Patients Following Open Method Surgery for Treatment of Cholesteatoma.

Two cases of primary cholesteatoma and 35 cases of secondary cholesteatoma were treated surgically using the open method and attended regularly for a follow-up period of at least one-year. Residual cholesteatoma was observed in seven cases, six of which appeared on the epitympanum or in the mastoid cavity and were easily removed via the external ear canal. In one case however, the cholesteatoma existed in the tympanic cavity and the patient was awaiting surgical treatment. At the last follow-up examination, closure of the air-bone gap to within 20dB had been achieved in 46% of the ears with the open method. Hearing improvement exceeding 10dB was obtained in 22% of the patients whereas 19% of the patients showed impaired hearing exceeding 10dB at the last follow-up when compared with the preoperative status. The authors concluded that the open method is a useful approach to surgical treatment for cholesteatoma when follow-up therapy is performed regularly.

Post-operative Evaluation of Cholesterol Granuloma.

Eight patients (six men and two women) who suffered from cholesterol granuloma were observed clinically for eight months to six years after undergoing surgical therapy. Four patients had blue ear drum, two patients had atelectatic ear, and two other patients had central perforation (one of which was large, the other of which was middle sized). Yellowish or brownish soft masses, which were the main cause of ear trouble in these patients, were identified by surgical microscopy during surgery, and these masses were confirmed to be cholesterol granulomas by histopathological examination in all of eight patients. Seven patients received combined approach tympanoplasty with an intact canal wall and another patient received modified radical mastoidectomy. One patient underwent reoperation because of the reappearance of cholesterol granuloma. Recurrence could not be prevented in one patients and the others did not complain of either otorrhea or any other ear problems during the follow-up observation period. A hearing improvement exceeding 15 dB was obtained in 4 cases, and none of the patients showed impaired hearing at the last follow-up examination, when compared with individual preoperative status. Cholesterol granuloma were found exclusively in the mastoid cavity and/or additus ad antrum in all patients, therefore the main pathogenesis of cholesterol granuloma of these patients appeared to be lack of ventilation of the mastoid cavity. We concluded that it was important to make and maintain a good ventilation passage from the tympanic cavity to the mastoid cavity by the surgery. It was often possible to cure cholesterol granuloma by middle ear surgery alone, without a ventilatory tympanic tube, when some function of the auditory tube remained.

Experimental Observation of Particulate Flow along Cranial Nerves

The purpose of this study was to investigate the communicative routes via the cranial nerves among the middle ear, the auditory tube, the inner ear, and the subarachnoid space under nearly physiological conditions. Various volumes of Indian ink were slowly injected into the facial nerve trunk of rabbits at the stylomastoid foramen, then serial sections of the heads were observed under the light microscope. This study yielded the following results: (i) Indian ink penetrated into the subarachnoid space through the internal auditory canal and/or the jugular foramen along the nerve sheaths of the VIIth, IXth, and/or Xth cranial nerves. (ii) Indian ink penetrated through the nerve sheaths of the cochlear, superior vestibular, and inferior vestibular nerves to the fundus of the internal auditory canal. (iii) Indian ink reached the scala tympani and the scala vestibuli via the cochlear aqueduct. (iv) Indian ink penetrated to the nerve sheaths of the tensor tympani and/or tensor palati nerves from the subarachnoid space of the trigeminal ganglion. In conclusion, it was shown that certain small particles are able to penetrate from the facial nerve sheath at the entrance of the stylomastoid foramen to the VIIIth, IXth, and Xth nerve trunks, the middle ear, the area around the auditory tube, the inner ear, and the subarachnoid space.

The Clinical Epidemiology of Ménière’s Disease: Functional Asymmetry

Acute or episodic vertigo is the most characteristic symptom of Meniere’s disease. This kind of vertigo appears when the function of the vestibular labyrinth abruptly becomes asymmetrical. Therefore, a study of the origin of the asymmetry or laterality of a labyrinthine lesion is needed; it could provide one of the keys in solving some of the problems concerning the pathogenesis and treatment of Meniere’s disease.