Stimulation Crosstalk Between Cochlear And Vestibular Spaces During Cochlear Electrical Stimulation.

OBJECTIVES: Possible beneficial "crosstalk" during cochlear implant stimulation on otolith end organs has been hypothesized. The aim of this case-control study is to analyze the effect of electrical cochlear stimulation on the vestibule (otolith end-organ), when using a cochleo-vestibular implant, comparing vestibular stimulation (VI) and cochlear stimulation (CI). METHODS: Four patients with bilateral vestibulopathy were included. A double electrode array research implant was implanted in all cases. Dynamic Gait Index (DGI), VOR gain measured by using vestibular head impulse test (vHIT), acoustic cervical myogenic responses (cVEMP) recordings, and electrical cVEMP were used in all cases. Trans-impedance Matrix (TIM) analysis was used to evaluate the current flow from the cochlea to the vestibule. RESULTS: While patients did not have any clinical vestibular improvement with the CI stimulation alone, gait metrics of the patients revealed improvement when the vestibular electrode was stimulated. The average improvement in the DGI was 38% when the vestibular implant was activated, returning to the normal range in all cases. Our findings suggest that any current flow from the cochlear space to the otolith organs was insufficient for effective cross-stimulation. The functional results correlated with the data obtained in TIM analysis, confirming that there is no current flow from the cochlea to the vestibule. CONCLUSION: The only way to produce effective electrical otolith end-organ stimulation, demonstrated with this research implant, is by direct electrical stimulation of the otolith end organs. No effective cross-stimulation was found from cochlear electrode stimulation. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:2349-2355, 2024.

Assessing the Placement of the Cochlear Slim Perimodiolar Electrode Array by Trans Impedance Matrix Analysis: A Temporal Bone Study.

New cochlear implant (CI) electrode arrays provide softer insertion dynamics; however, due to their high flexibility, the possibilities of fold-overs or intraoperative displacements must be taken into account. The position of each individual electrode can only be determined by using high-resolution computed tomography or cone-beam CT. The trans-impedance matrix test (TIM) is an electrophysiological method based on electric field imaging that can provide images of electrode position and electrode folding. OBJECTIVE: In this experimental research, we evaluated the result of TIM as a method of monitoring cochlear insertion for a precurved slim modiolar electrode array in fresh human temporal bones by analyzing the transimpedance matrix patterns and their correlation with electrode position using high-resolution computed tomography. MATERIAL AND METHODS: Sixteen slim modiolar electrode arrays were inserted into eight fresh Human Temporal Bones. Eight electrodes were inserted according to the correct methodology of insertion, and eight were intentionally folded over. After all insertions, a trans-impedance matrix analysis and a Cone Beam CT (CBCT) were performed in each temporal bone. RESULTS: If we correlated the TIM patterns with the radiological electrode position, we observed that better electrode intracochlear positions indicated more "homogeneous" TIM patterns (intracochlear voltage dropped monotonically as the distance between stimulation and recording contact increased, both toward the apex and toward the base). A correlation where fold-over was detected in the TIM results was found in all eight temporal bone radiological findings. CONCLUSIONS: Trans-Impedance Matrix patterns were correlated with the radiological CI electrode position. When a tip fold-over appeared, a matrix with a secondary ridge in addition to the primary ridge was observed in all cases. TIM can be an effective method in the control of electrode positioning.

Papilomatosis confluente y reticulada de Gougerot-Carteaud / CONFLUENT AND RETICULATED PAPILLOMATOSIS OF GOUGEROT-CARTAUD

La papilomatosis confluente y reticulada de Gougerot-Cartaud es una dermatosis poco frecuente, de etiología incierta. Afecta a adolescentes y adultos jóvenes, con leve predilección por el sexo masculino. Se presenta como pápulas parduzcas que confluyen formando placas centrales con patrón reticulado en la periferia, asintomáticas o levemente pruriginosas. La localización característica es tronco anterior y posterior, a nivel de la línea media. Los antibióticos orales, principalmente la minociclina, constituyen el tratamiento de elección. Debe diferenciarse de otras entidades, entre ellas pitiriasis versicolor, acantosis nigricans y dermatosis terra firma-forme. Se presenta una paciente de 17 años con papilomatosis confluente y reticulada de GougerotCarteaud que respondió satisfactoriamente al tratamiento con minociclina vía oral y tretinoína 0,025% tópica.

Confluent and reticulated papillomatosis of Gougerot-Cartaud is a rare dermatosis, of still uncertain etiology. It affects adolescents and young adults, with a slight predilection for males. It presents as asymptomatic or slightly pruritic brownish papules that converge to form central plaques with a reticulated pattern on the periphery. The characteristic location is midline anterior and posterior trunk. Oral antibiotics, mainly minocycline, are the treatment of choice. It must be differentiated from other entities, including pityriasis versicolor, acanthosis nigricans, and terra firme-forme dermatosis. We present a 17-year-old patient with confluent Gougerot-Carteaud papillomatosis who responded satisfactorily to treatment with oral minocycline and topical tretinoin 0.025%.

Cochlear Implants in Single-Sided Deafness. Comparison Between Children and Adult Populations With Post-lingually Acquired Severe to Profound Hearing Loss.

Objective: To determine audiological and clinical results of cochlear implantation (CI) comparing two populations with single-sided deafness (SSD): post-lingually deaf children between 6 and 12 years of age, and post-lingually deaf adults, in order to evaluate the effect of CI in different age groups. Design: Retrospective case review. Setting: Tertiary clinic. Patients and Method: Twenty-three children and twenty-one adult patients that were candidates for CI with single-side deafness were included. In all cases we evaluate: Speech perception thresholds; disyllabic words test (65 dB SPL) were performed in the modalities S0-SCI-SNH and Auditory Lateralization Test. The Speech, Spatial, and Qualities of Hearing Scale (SSQ) questionnaire was also used. All results were obtained after 12 months of CI activation. Results: In children, the most common etiology was idiopathic sensory-neural hearing loss. They showed positive results in the Auditory Lateralization Test. In the Speech Test, word recognition in noise improved from 2% preoperatively to 61.1% at a mean follow-up of 1 year (S0 condition) in children [test with signal in CI side 60% and signal normal hearing side (plugged) 31%]. The processor was used for >12 h in all cases. With respect to the SSQ questionnaire, parents were more satisfied within the postoperative period than within the preoperative period. For adults, the most common etiology was idiopathic sudden sensorineural hearing loss (SNHL). Positive results in the Auditory Lateralization Test were found. With respect to the Speech Test in quiet conditions: Word recognition in noise improved from 5.7% preoperatively to 71.8% at a mean follow-up of 1 year [test with signal in CI side 68% and signal normal hearing side (plugged) 41%]. The processor was used for >12 h. In the SSQ questionnaire, the post-operative results showed a beneficial effect of the CI. No adverse events were reported during the study period. No differences were found between children and adults in all tests in this study. Conclusions: Cochlear implantation in post-lingually deaf adults and children with SSD can achieve a speech perception outcome comparable with CI in conventional candidates. Improvements in spatial hearing were also observed. Careful patient selection and counseling regarding potential benefits are important to optimize outcomes.