Degree of pneumatization of the temporal bone and Menière's disease: are they related?

Effect of pre-operative mastoid pneumatisation on tympanoplasty success

Objective

This study aimed to compare the effect of pneumatised and non-pneumatised mastoid on the success of tympanoplasty in terms of rate of graft uptake and air–bone gap improvement.

Method

A comprehensive electronic search of PubMed Medline, Scopus, Web of Science and Cochrane Library was conducted in August 2020 for articles from 1990 to 2020. Selected studies were published in the English language, were conducted on human patients, were concerned with evaluating pre-operative mastoid pneumatisation on tympanoplasty success, were not laboratory studies and were not opinion studies. Five studies were included with 178 patients in the pneumatised group and 97 patients were included in the non-pneumatised group. Comparison between both groups was performed in terms of graft uptake rate and air–bone gap improvement.

Results

Although the pneumatised group showed better graft uptake rate than the non-pneumatised group, there was no statistically significant difference between the two groups in the success rate of tympanoplasty.

Conclusion

Pneumatisation of the mastoid does not significantly affect the success rate of tympanoplasty.

Identification of early inflammatory changes in the tympanic membrane with Raman spectroscopy

The tympanic membrane (TM) is a dynamic structure that separates the middle ear from the external auditory canal. It is also integral for the transmission of sound waves. In this study, we demonstrate the feasibility of using Raman spectroscopy to identify early chemical changes resulting from inflammation in the TM that can serve as an indicator of acute otitis media. Bacterial lipopolysaccharide (LPS) was injected trans-tympanicaly in a murine model. Presence of inflammatory response was assessed with binocular microscopy, confirmed with histopathology and immunofluorescence staining. Successful discrimination suggesting spectral differences among the control and LPS treated groups was achieved using principal component analysis. Raman imaging revealed major differences in collagen distribution and nucleic acid content. Image segmentation analysis on the trichrome stained tissue sections was performed to corroborate the Raman spectra. The spectral co-localization study suggests changes in the expression of collagen IV specific signals in LPS treated samples. The overall findings of the study support prospective application of RS in the diagnosis and therapeutic monitoring of otitis media.

Impact of the Degree of the Mastoid Pneumatization on Cartilage Type 1 Tympanoplasty Success

OBJECTIVES

To evaluate the effect of the degree of the mastoid pneumatization on the success rate of cartilage type 1 tympanoplasty.

STUDY DESIGN

A retrospective clinical chart review.

METHODS

In total, 90 patients (44 females and 46 males; average age, 38.40 ± 11.12 years; age range: 21-65 years) who underwent cartilage type 1 tympanoplasty were included. Demographics and anatomical outcomes were recorded. The patients were divided into 2 groups in terms of anatomical success. In group A, all patients had intact grafts without perforation, retraction, or lateralization, and a dry ear, at 6 months postoperatively. In group B, reperforation of the tympanic membrane was evident 6 months postoperatively. The mastoid air cell volumes of each groups were compared.

RESULTS

The mean mastoid pneumatization in groups A and B was 5.32 ± 1.96  and 5.06 ± 2.12 cm, respectively. The mastoid pneumatization of diseased ears did not differ between the groups (P > 0.05). The mastoid pneumatization of diseased ears did not differ between males and females (P > 0.05). The mastoid pneumatization of normal ears did not differ between the groups (P > 0.05). The mastoid pneumatization of normal ears did not differ between males and females (P > 0.05).

CONCLUSIONS

The degree of mastoid pneumatization did not affect the success rate of cartilage type 1 tympanoplasty. Further studies with larger numbers of patients are needed to evaluate the relationship between the degree of the mastoid pneumatization and anatomical outcomes after placement of various graft types.

Cochlin in normal middle ear and abnormal middle ear deposits in DFNA9 and Coch (G88E/G88E) mice

DFNA9 sensorineural hearing loss and vestibular disorder, caused by mutations in COCH, has a unique identifying histopathology including prominent acellular deposits in cochlear and vestibular labyrinths. A recent study has shown presence of deposits also in middle ear structures of DFNA9-affected individuals (McCall et al., J Assoc Res Otolaryngol 12:141-149, 2004). To investigate the possible role of cochlin in the middle ear and in relation to aggregate formation, we evaluated middle ear histopathology in our Coch knock-in (Coch (G88E/G88E) ) mouse model, which harbors one of the DFNA9-causative mutations. Our findings reveal accumulation of acellular deposits in the incudomalleal and incudostapedial joints in Coch (G88E/G88E) mice, similar to those found in human DFNA9-affected temporal bones. Aggregates are absent in negative control Coch (+/+) and Coch (-/-) mice. Thickening of the tympanic membrane (TM) found in humans with DFNA9 was not appreciably detected in Coch (G88E/G88E) mice at the evaluated age. We investigated cochlin localization first in the Coch (+/+)mouse and in normal human middle ears, and found prominent and specific cochlin staining in the incudomalleal joint, incudostapedial joint, and the pars tensa of the TM, which are the three sites where abnormal deposits are detected in DFNA9-affected middle ears. Cochlin immunostaining of Coch (G88E/G88E) and DFNA9-affected middle ears showed mutant cochlin localization within areas of aggregates. Cochlin staining was heterogeneous throughout DFNA9 middle ear deposits, which appear as unorganized and overlapping mixtures of both eosinophilic and basophilic substances. Immunostaining for type II collagen colocalized with cochlin in pars tensa of the tympanic membrane. In contrast, immunostaining for type II collagen did not overlap with cochlin in interossicular joints, where type II collagen was localized in the region of the chondrocytes, but not in the thin layer of the articular surface of the ossicles nor in the eosinophilic deposits with specific cochlin staining.

Elevated autoantibodies in sera from otosclerotic patients are related to the disease duration

In this study an indirect ELISA with patients' sera was performed using human collagen type II, double- (dsDNA) and single-stranded DNA (ssDNA), thyroid microsomal antigen, insulin and lysozyme as antigens. Since many preoperated otosclerotic patients demonstrated the signs of myringosclerosis (n=7). they were classified separately and compared with otosclerotic patients without myringosclerosis (n=28), with healthy controls (n=42) and with patients with tympanosclerosis (n=5) of other origin. The otosclerotic patients had serum antibodies to antigens tested similar to normal controls. However, elevated antibody levels to human collagen type II, dsDNA and ssDNA were observed only in patients with a disease duration between 3 and 5 years as compared to other otosclerotic patients. The same duration association was observed in the level of the total serum alkaline phosphatase activity. These observations would suggest that the enzymatic bone resorption is the driving force in human otosclerosis. Elevated serum autoantibodies during tissue reparation in the otosclerotic stage may be a transient response to sustained excess antigen turnover in the primary lesion.

Plain radiological findings in Ménière's disease

In order to investigate the characteristics of plain radiography of Ménière's disease, the degree of the pneumatization and the distance between the sigmoid plate and the bony wall of the vestibule in Schüller's view were examined in patients with unilateral and bilateral Ménière's disease, non-Ménière vertiginous disease and healthy subjects. There was no difference of the degree of pneumatization and the distance among the patients with Ménière's disease, the non-Ménière inner ear disease group and in healthy subjects. The distance of the unaffected ear was significantly shorter in patients showing a shorter distance of the affected ear. There was no relationship between the distance and age of onset of the disease, and duration of the disease. Therefore, it is concluded that the dysfunction of endolymphatic sac does not always reflect poor mastoid pneumatization and/or shorter distance in the plain radiography and that other etiological mechanisms such as autoimmune disease should be considered in some patients having evidence of endolymphatic hydrops.

Otosclerosis. Treating progressive hearing loss in young adults

When a patient presents with bilateral progressive hearing loss and has a family history of hearing loss, otosclerosis should be placed high on the list of possible causes. Primary care physicians should determined whether the hearing loss is conductive or sensorineural with otologic examination and tuning-fork evaluation. Unless there is an obvious reversible cause for the progressive hearing loss, the patient should be referred to an otolaryngologist for more intensive otologic and audiologic examination. The patient's principal concern is the ability to hear and comprehend the spoken word in normal circumstances. Fortunately, most patients can be rehabilitated with surgery or a hearing aid. Fluoride treatment may have a significant role in preventing further hearing loss from otosclerosis.