MR sialographic assessment of the masseter muscle and the ductal kinking in patients with recurrent parotitis

Dysfunction of the masseter muscle may cause pathological kinking of the parotid duct leading to parotitis; MR sialography is a non-invasive radiological examination that allows to evaluate dynamically the ductal system of the parotid glands. In the present study we aimed to assess the relationships between Stensen's duct and masseter muscle and their implications in the aetiopathogenesis of recurrent parotitis secondary to masseter muscle dysfunction. Forty-one patients with recurrent unilateral parotitis and nine with bilateral recurrent parotitis, all with a clinical suspicious of masseter muscle hypertrophy due to bruxism were enrolled. They underwent ultrasonography as a first line examination and then MR sialography and sialendoscopy. Different anatomical features were studied. Involved parotid glands had a wider duct compared to contralateral unaffected parotid glands of patients with recurrent parotitis (p = 0.00134); male subjects with parotitis had a longer duct compared to the salivary glands of healthy patients (p = 0.00943 for affected glands and p = 0.00629 for the contralateral). A concordance between the evidence of an acute duct angle during sialendoscopy and a wider duct in patients with parotitis was observed although not statistically significant. These initial findings suggest that the masticatory muscle dysfunction related to bruxism seems to condition alteration of parotid duct course and anatomy thus favouring the occurrence of recurrent parotitis. A specific diagnostic iter based on clinical evaluation, dynamic ultrasonography and MR sialography, is therefore, mandatory to confirm the relationship between masseter muscle anatomy and parotid duct anomalies; this is the premise for an adequate therapeutic approach to underlying masticatory muscle disorder.

Amyotrophic lateral sclerosis with upper motor neuron predominance: diagnostic accuracy of qualitative and quantitative susceptibility metrics in the precentral gyrus

OBJECTIVE

The study aims at comparing the diagnostic accuracy of qualitative and quantitative assessment of the susceptibility in the precentral gyrus in detecting amyotrophic lateral sclerosis (ALS) with predominance of upper motor neuron (UMN) impairment.

METHODS

We retrospectively collected clinical and 3T MRI data of 47 ALS patients, of whom 12 with UMN predominance (UMN-ALS). We further enrolled 23 healthy controls (HC) and 15 ALS Mimics (ALS-Mim). The Motor Cortex Susceptibility (MCS) score was qualitatively assessed on the susceptibility-weighted images (SWI) and automatic metrics were extracted from the quantitative susceptibility mapping (QSM) in the precentral gyrus. MCS scores and QSM-based metrics were tested for correlation, and ROC analyses.

RESULTS

The correlation of MCS score and susceptibility skewness was significant (Rho = 0.55, p < 0.001). The susceptibility SD showed an AUC of 0.809 with a specificity and positive predictive value of 100% in differentiating ALS and ALS Mim versus HC, significantly higher than MCS (Z = -3.384, p-value = 0.00071). The susceptibility skewness value of -0.017 showed specificity of 92.3% and predictive positive value of 91.7% in differentiating UMN-ALS versus ALS mimics, even if the performance was not significantly better than MCS (Z = 0.81, p = 0.21).

CONCLUSION

The MCS and susceptibility skewness of the precentral gyrus show high diagnostic accuracy in differentiating UMN-ALS from ALS-mimics subjects. The quantitative assessment might be preferred being an automatic measure unbiased by the reader.

CLINICAL RELEVANCE STATEMENT

The clinical diagnostic evaluation of ALS patients might benefit from the qualitative and/or quantitative assessment of the susceptibility in the precentral gyrus as imaging marker of upper motor neuron predominance.

KEY POINTS

• Amyotrophic lateral sclerosis diagnostic work-up lacks biomarkers able to identify upper motor neuron involvement. • Susceptibility-weighted imaging/quantitative susceptibility mapping-based measures showed good diagnostic accuracy in discriminating amyotrophic lateral sclerosis with predominant upper motor neuron impairment from patients with suspected motor neuron disorder. • Susceptibility-weighted imaging/quantitative susceptibility mapping-based assessment of the magnetic susceptibility provides a diagnostic marker for amyotrophic lateral sclerosis with upper motor neuron predominance.

Impact of Cochlear Implant Array Placement on Speech Perception

PURPOSE

To assess the role of flat panel computed tomography (FPCT) in the evaluation of cochlear implant (CI) electrode position and its relation to speech perception.

METHODS

From March 2015 to March 2019, we retrospectively enrolled deaf subjects ≥ 18 years who underwent unilateral CI by one surgeon, imaged with FPCT and assessed with disyllabic words score before CI and at 6 months of follow-up. We calculated the disyllabic score difference before CI and after CI (ΔSDS) and divided the subjects in favorable and unfavorable outcome groups using the median ΔSDS as a cutoff. We compared the demographic, clinical, electrode characteristics, and the CI positioning variables scalar position, surgical insertion depth (SID), linear insertion depth (LID), angular insertion depth (AID) and wrapping factor (WF).

RESULTS

We studied 50 subjects (F/M = 27/23; median age = 60.5 years, IQR: 50-70 years). The median ΔSDS was 80% (interquartile range [IQR]: 60-100%) in quiet and 80% (IQR: 47.5-100%) in noise. Of the subjects 23 demonstrated a favorable outcome and had earlier age at CI (median 52 years; IQR 45-67 years versus median 62 years; IQR: 56-71 years p = 0.032) and a significantly higher SID (median: 4.02 mm IQR: 3.00-5.35 mm versus median: 2.94 mm IQR: 2.06-3.90 mm; p = 0.029). No difference was found for LID (p = 0.977), AID (p = 0.302), and WF (p = 0.224). A logistic regression model built with the age at CI, number of CI electrodes, and the SID was significant χ2 ((df = 3, N = 50) = 14.517, p = 0.002). The model explained 33.7% (Nagelkerke R2) of ΔSDS variance and correctly classified 76% of the cases.

CONCLUSION

The SID measured by FPCT predicts the ΔSDS at 6 months follow-up, alongside with age at implantation and number of CI electrodes.

Assessment of Frequency-Place Mismatch by Flat-Panel CT and Correlation With Cochlear Implant Performance

OBJECTIVE

To calculate the frequency allocation mismatch in a group of very selected cochlear implant (CI) recipients and to contrast it with the speech perception performances.

STUDY DESIGN

Cross-sectional observational prospective study.

SETTINGS

Tertiary Audiological Department, University hospital.

PATIENTS

Fifteen adults receiving the same CI array by the same surgeon through a posterior tympanotomy, round window approach.

MAIN OUTCOME MEASURES

1) High definition flat panel computed tomography (FPCT) control of the intracochlear position of each electrode contact, and computation of the relative frequency allocation mismatch; 2) analysis of speech perception outcomes in relation with the mismatch.

RESULTS

Despite a consistent and reproducible surgical procedure with the same intracochlear array, significant deviations from the frequency allocation tables (FAT) assigned by default by the manufacturer were observed in this study.Their influences on speech perception performances were negligible in the simple tasks of words or sentences recognition in quiet (and, to a lesser extent also in noise). The greatest effect of a significant mismatch was observed for the vocal-consonant-vocal (VCV) sequences recognition under noise masking, the emotional and the linguistic prosody recognition, and the phonemes discrimination of the Auditory Speech Sound Evaluation (A§E) test.

CONCLUSIONS

The greatest frequency-to-place occurred at the high frequencies. The effect was rather irrelevant on simple words and sentences recognition, while it negatively impacted on the more complex perceptual tasks.

Audiovestibular Phenotypes and Advanced Magnetic Resonance Imaging Features of Cochlin Gene Mutation Carriers

OBJECTIVE

To describe clinical and imaging findings in a group of patients affected by nonsyndromic deafness A9 (DFNA9), using advanced magnetic resonance imaging (MRI) with 3-dimensional (3D) fluid-attenuated inversion recovery (FLAIR) sequence.

METHOD

A retrospective case review was conducted in a tertiary referral center in Italy. Four sequential adult DFNA9-affected patients, who had undergone MRI at our Department between January 2017 and June 2018, were enrolled (male = 2, female = 2; median age: 65.6 years; 8 diseased ears analyzed). Three patients were relatives; the fourth was unrelated. The main outcome measures - age, sex, records of audiological and vestibular testing, genetic assessment, MRI findings - were analyzed.

RESULTS

All subjects suffered from bilateral progressive sensorineural hearing loss, more severely at the high frequencies and with a typical clinical pattern of bilateral chronic degenerative cochleovestibular deficit. Aural fullness was reported at the onset of the disease. All patients revealed a pathogenic heterozygous mutation in the Limulus factor C, Coch-5b2 and Lgl1 domain of cochlin. None of the patients showed a significant vestibular and cochlear endolymphatic hydrops at MRI, while high bilateral contrast enhancement on 4-h delayed postcontrast 3D FLAIR sequence was observed in all ears.

CONCLUSIONS

Increased perilymph enhancement on 4-h delayed postcontrast 3D FLAIR sequence is the common imaging feature of DFNA9 ears, suggesting that blood-labyrinthine barrier breakdown may play the main role in the pathophysiology of this disease. Significant hydrops has been excluded by MRI. This finding might be clinically useful in differentiating DFNA9 disease from other pathologies with similar clinical findings like Ménière's disease.