Keijiro Koga

Radiographic diagnosis of congenital bony nasal stenosis.

Congenital bony nasal stenosis (CBNS) is a rare condition that causes respiratory distress in neonates. Between 1986 and 1996, we encountered 13 cases of CBNS. Recently, CT measurements have been used to evaluate the features of this type of stenosis, but no satisfactory investigation of the severity of bony nasal stenosis has been reported. We compared the nasal width (NW), facial width (FW), and interorbital distance (IOD) measured from occipitofrontal (Caldwells) projections of plain radiographs in nine CBNS patients and nine normal infants. NW was significantly narrower in the CBNS patients than in the controls, and never exceeded the IOD in any of the CBNS patients. This measuring method can be used to diagnose CBNS, because NW in normal subjects of all age groups is always greater than IOD on Caldwells view. We also investigated one patient radiographically, to determine how NW increased until the age of 4 years. However, there was no significant change in nasal width, although the FW increased significantly. This method seems useful for determining the severity of stenosis, and its simplicity makes it useful for routine investigation of breathing difficulty in neonates and infants. We review and discuss the CT images of CBNS reported in the literature.

Immunological Study on Association between Mumps and Infantile Unilateral Deafness

The incidence of unilateral deafness in primary school children has been reported to be about 0.1%, but the cause of most of these cases has not been clarified, because parents and children themselves cannot recognize the onset of hearing loss occurring in one ear alone. This study was performed to clarify the possibility that mumps causes infantile unilateral deafness. The results were: 1) on dividing a total of 78 cases of infantile unilateral deafness according to age from 3 to 6 years, mumps infection rate in the 4-year-old group was nearly twice that in a randomly selected group; 2) on checking the neutralizing or ELISA IgG test of 31 cases with no history of mumps only, the 4-year-old group demonstrated a positive reaction to mumps more than the randomly selected group did. The above results suggested that unilateral deafness may be caused by asymptomatic mumps infection. To confirm this, we studied 5 infantile cases of sudden hearing loss by means of ELISA IgM antibody test and found a bilateral sudden deafness in children aged 1.9 years, caused by asymptomatic mumps infection.

A Long-term Follow-up Stady on Perceptive Deafness (3-8 years)

Hearing of patients of perceptive deafness, most of them due to unknown cause, was studied for more than 3 years until 8 years. The hearing loss was not changed in 35 cases but it was aggravated in 20 cases and fluctuated in 13 cases in this series.The hearing impairment of aggravated group was initiated at the high frequencies and extended to the low frequencies.The hearing loss at low frequeucies was larger in fluctuated group than in aggravated group.One patient in aggravated group showed that the aggravation of haring impairment in one ear was followed by that in the other ear. One patient in fluctuated group showed the fluctuotion of hearing in both ear simultaneously.