Anne-Lise Poirrier

Oxidative Stress in the Cochlea: An Update

This paper will focus on understanding the role and action of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the molecular and biochemical pathways responsible for the regulation of the survival of hair cells and spiral ganglion neurons in the auditory portion of the inner ear. The pivotal role of ROS/RNS in ototoxicity makes them potentially valuable candidates for effective otoprotective strategies. In this review, we describe the major characteristics of ROS/RNS and the different oxidative processes observed during ototoxic cascades. At each step, we discuss their potential as therapeutic targets because an increasing number of compounds that modulate ROS/RNS processing or targets are being identified.

Ototoxic drugs: Difference in sensitivity between mice and guinea pigs

The development of experimental animal models has played an invaluable role in understanding the mechanisms of neurosensory deafness and in devising effective treatments. The purpose of this study was to develop an adult mouse model of ototoxic drug-induced hearing loss and to compare the ototoxicity in the adult mouse to that in the well-described guinea pig model. Mice are a powerful model organism, especially due to the large availability of antibodies, probes and genetic mutants. In this study, mice (n=114) and guinea pigs (n=35) underwent systemic treatment with either kanamycin or cisplatin. Auditory brainstem responses showed a significant threshold shift in guinea pigs 2 weeks after the beginning of the ototoxic treatment, while there was no significant hearing impairment recorded in mice. Hair cells and neuronal loss were correlated with hearing function in both guinea pigs and mice. These results indicate that the mouse is not a good model for ototoxicity, which should be taken into consideration in all further investigations concerning ototoxicity-induced hearing loss.

Ephrin-A5/EphA4 signalling controls specific afferent targeting to cochlear hair cells

Hearing requires an optimal afferent innervation of sensory hair cells by spiral ganglion neurons in the cochlea. Here we report that complementary expression of ephrin-A5 in hair cells and EphA4 receptor among spiral ganglion neuron populations controls the targeting of type I and type II afferent fibres to inner and outer hair cells, respectively. In the absence of ephrin-A5 or EphA4 forward signalling, a subset of type I projections aberrantly overshoot the inner hair cell layer and invade the outer hair cell area. Lack of type I afferent synapses impairs neurotransmission from inner hair cells to the auditory nerve. By contrast, radial shift of type I projections coincides with a gain of presynaptic ribbons that could enhance the afferent signalling from outer hair cells. Ephexin-1, cofilin and myosin light chain kinase act downstream of EphA4 to induce type I spiral ganglion neuron growth cone collapse. Our findings constitute the first identification of an Eph/ephrin-mediated mutual repulsion mechanism responsible for specific sorting of auditory projections in the cochlea.

Is the Sino-Nasal Outcome Test-22 a suitable evaluation for septorhinoplasty?†

It is becoming increasingly important for clinicians to demonstrate the impact of their interventions. The Sino‐Nasal Outcome Test‐22 (SNOT‐22) questionnaire is a disease‐specific questionnaire involving 22 symptoms combining rhinologic issues with general health issues. We evaluated the SNOT‐22 score as a quality‐of‐life outcome measure in septorhinoplasty surgery.

Contribution of postero-anterior cephalometry in obstructive sleep apnea.

Lateral cephalometry has been widely used to characterize facial and maxillary morphology in obstructive sleep apnea (OSA) patients. It is a useful tool to assess orthodontic and maxillofacial procedures, but transverse dimensions of the airway (e.g., nasal framework) have not been well described yet by cephalometry. We explored whether postero‐anterior cephalometry could refine the analysis of the facial morphology, with a special attention paid to nasal morphology. We validated cephalometric measurements relevant to the diagnosis of OSA.

The need for an objective measure in septorhinoplasty surgery: are we any closer to finding an answer?

To assess the reliability of nasal inspiratory peak flow (NIPF) in providing a clinically accurate objective measure following functional septorhinoplasty by comparing it to the validated disease‐specific quality‐of‐life questionnaire, SNOT‐22. Studies so far have demonstrated poor correlation between bilateral NIPF and symptom‐specific nasal questionnaires following septorhinoplasty.

Sphenoid sinus fungall ball: A retrospective study over a 10-year period

A fungal ball consists of a dense conglomerate of fungal hyphae growing at the surface of the sinus mucosa without tissue infiltration. The maxillary sinus is by far the most commonly involved paranasal sinus cavity followed by the sphenoid sinus. The present study is a retrospective study of 25 consecutive cases treated during the last 10 years in the two hospitals be- longing to the Catholic University of Louvain (CHU Mont-Godinne and UCL Saint Luc). We report the symptomatology, the imaging and discuss the different surgical managements. We conclude that the clinician must have a high index of suspicion when dealing with a unilateral rhinosinusitis persisting despite a maximal and well conducted medical treatment. This is particularly so in elderly women when associated with facial pain and post nasal drip, particularly when the computed tomography shows an unilateral opacity of the sphenoid sinus with or without a sclerosis or an erosion of the bony walls, a polyp in the sphenoethmoidal recess or a hyperdensity mimicking a foreign body. An endonasal endoscopic sphenoidotomy is the treatment of choice in most cases, allowing good ventilation of the sinus and radical removal of all the fungal concretion. A biopsy of the sinus mucosa adjacent to fungal elements is of upmost important to confirm the non- invasiveness of the fungi within the tissue. Antifungal medication is not required in uncomplicated forms. All host factors producing some degree of immunosuppression must be corrected when present and must alert the clinician to rule out any forms of invasive disease.

French adaptation and validation of the Sino-Nasal Outcome Test-22: a prospective cohort study on quality of life among 422 subjects

ENT surgeons are facing an ever‐increasing demand to demonstrate their efficacy. The 22‐item Sino‐Nasal Outcome Test (SNOT‐22) is a fully validated and easy‐to‐use outcome measure in rhinology. Our goal was to translate and validate the SNOT‐22 in a cohort of 422 French‐speaking subjects.

Outcomes in Endoscopic Sinus Surgery : Olfaction, NOSE scale and Quality of Life in a Prospective Cohort Study.

To determine the efficacy of endoscopic sinus surgery (ESS) on olfactory function in chronic rhinosinusitis patients with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP) and to compare the nasal obstruction and symptom evaluation (NOSE) scale before and after surgery.

Anatomical variations of the lateral nasal wall: The secondary and accessory middle turbinates.

The aim of the current anatomical and clinical study was to audit our cases of patients who presented with secondary and/or accessory middle turbinates during a two‐year period. We investigated the incidence and the clinical impact of these variations. Twenty‐eight patients, 19 males and 9 females with a mean age of 41.5 years, representing different ethnic origins, were diagnosed with double middle turbinates based on endoscopic examination. Of those, 92.8% had a main symptom of refractory frontal headache. A secondary nasal symptom was sensation of blocked nose. Patients who underwent endoscopic surgery (n = 13) for reduction of the extra turbinate, reported significant symptom scores improvement (P < 0.0001) of frontal headache and blocked nose, from means of 9.07 ± 0.26 and 8.57 ± 1.39 to 1 ± 0.31, and 1.42 ± 0.35, respectively. Our results indicate that double middle turbinates may be encountered in rhinology practice (2%). Clinically they may present with refractory headache and blocked nose. Endoscopic surgical approach seems to be an effective way of improving the symptoms. Clin. Anat. 25:340–346, 2012.