Naima Deggouj

Tinnitus specifically alters the top-down executive control sub-component of attention: Evidence from the Attention Network Task.

Tinnitus can be defined as the perception of noxious disabling internal sounds in the absence of external stimulation. While most individuals with tinnitus show some habituation to these internal sounds, many of them experience significant daily life impairments. There is now convincing evidence that impairment in attentional processes may be involved in tinnitus, particularly by hampering the habituation mechanism related to the prefrontal cortex activity. However, it is thus still unclear whether this deficit is an alteration of alerting and orienting attentional abilities, or the consequence of more general alteration in the executive control of attention. In the present study, 20 tinnitus patients were compared to 20 matched healthy controls using the Attention Network Test, to clarify which attentional networks, among alerting, orienting, and executive networks, show differences between the groups. The results showed that patients with tinnitus do not present a general attentional deficit but rather a specific deficit for top-down executive control of attention. This deficit was highly correlated with patient characteristics of years of tinnitus duration and the frequency of coping strategies employed to alleviate tinnitus distress in daily life. These findings are discussed in terms of recent neurobiological models suggesting that prefrontal cortex activity might especially be related to tinnitus habituation. Therapeutic perspectives focusing both on rehabilitation of the executive control of attention and neuromodulation are also discussed.

Prognostic Value of Olfactory Bulb Volume Measurement for Recovery in Postinfectious and Posttraumatic Olfactory Loss

Objectives Several prognostic factors influencing the recovery from olfactory dysfunction have been described. The aim of this study was to investigate whether olfactory bulb volume could be used as a new predictor of olfactory recovery in postinfectious and posttraumatic olfactory loss. Study Design Cohort study; Level of evidence, 4. Setting Tertiary university clinic, department of otolaryngology. Subjects and Methods A cohort of 60 patients with postinfectious (n = 28) and posttraumatic olfactory loss (n = 32) was investigated. Assessment of olfactory function was performed using orthonasal (Sniffin’ Sticks test) and retronasal psychophysical olfactory tests, at the time of the diagnosis (t1) and 15 months later (t2). All patients were examined on 3 tesla magnetic resonance imaging, and the olfactory bulbs volume was assessed using planimetric contouring at the time of the diagnosis (t1). Results Recovery rate was 25% in patients with posttraumatic olfactory loss and 36% in patients with postinfectious olfactory loss. There was a correlation between both orthonasal and retronasal olfactory testing and the initial measurement of the total olfactory bulb volume. In addition, we observed a significant correlation between changes in olfactory functions and initial measurement of the total olfactory bulb volume, with larger volumes relating to higher improvement of olfactory function. Finally, we found that none of the patients with a total olfactory bulb volume of 40 mm3 or less exhibited recovery of olfactory function. Conclusion Olfactory bulb volume seems to be a predictor of olfactory recovery in patients with postinfectious and posttraumatic olfactory loss.

Non-sinonasal-related olfactory dysfunction: A cohort of 496 patients.

INTRODUCTION AND AIM There is a high prevalence of olfactory dysfunction in the general population. Several causes of olfactory dysfunction have been reported and this disorder is classically divided into sinonasal and non-sinonasal-related olfactory dysfunction. The aims of this study were firstly, to evaluate the frequency of the various aetiologies of olfactory dysfunction in a population of patients with non-sinonasal-related olfactory dysfunction and secondly, to evaluate the degree of olfactory impairment associated with these various aetiologies. MATERIAL AND METHODS We retrospectively reviewed a cohort of 496 patients with non-sinonasal-related olfactory dysfunction. The aetiology of the olfactory dysfunction was recorded for each patient. The aetiology was determined by a complete clinical assessment, including medical history, complete otorhinolaryngological examination, psychophysical testing of olfactory function, recording of olfactory event-related potentials and brain magnetic resonance imaging. Six groups of patients were defined on the basis of the aetiology of the disease and orthonasal and retronasal psychophysical olfactory performances were evaluated in each group. RESULTS Post-infectious and post-traumatic aetiologies were the most common causes, representing 37.9% and 33.1% of patients, respectively, followed by idiopathic (16.3%), congenital (5.9%), toxic (3.4%) and neurological (3.4%) olfactory dysfunction. Anosmia was significantly more frequent in congenital (93.1%) and post-traumatic (62.8%) olfactory dysfunction, whereas hyposmia was more frequent in the post-infectious group (59.6%). Orthonasal and retronasal olfactory function tests were significantly correlated in all groups except for the congenital group. CONCLUSIONS The data of this study confirm that the most common causes of non-sinonasal-related olfactory dysfunction are post-infectious and post-traumatic. Post-infectious olfactory dysfunction is mainly observed in middle-aged women and is mainly associated with hyposmia, whereas post-traumatic olfactory dysfunction is mainly observed in young men and is associated with a high rate of anosmia.

A European Perspective on Auditory Processing Disorder-Current Knowledge and Future Research Focus

Current notions of “hearing impairment,” as reflected in clinical audiological practice, do not acknowledge the needs of individuals who have normal hearing pure tone sensitivity but who experience auditory processing difficulties in everyday life that are indexed by reduced performance in other more sophisticated audiometric tests such as speech audiometry in noise or complex non-speech sound perception. This disorder, defined as “Auditory Processing Disorder” (APD) or “Central Auditory Processing Disorder” is classified in the current tenth version of the International Classification of diseases as H93.25 and in the forthcoming beta eleventh version. APDs may have detrimental effects on the affected individual, with low esteem, anxiety, and depression, and symptoms may remain into adulthood. These disorders may interfere with learning per se and with communication, social, emotional, and academic-work aspects of life. The objective of the present paper is to define a baseline European APD consensus formulated by experienced clinicians and researchers in this specific field of human auditory science. A secondary aim is to identify issues that future research needs to address in order to further clarify the nature of APD and thus assist in optimum diagnosis and evidence-based management. This European consensus presents the main symptoms, conditions, and specific medical history elements that should lead to auditory processing evaluation. Consensus on definition of the disorder, optimum diagnostic pathway, and appropriate management are highlighted alongside a perspective on future research focus.

EDNRB mutations cause Waardenburg syndrome type II in the heterozygous state

Waardenburg syndrome (WS) is a genetic disorder characterized by sensorineural hearing loss and pigmentation anomalies. The clinical definition of four WS types is based on additional features due to defects in structures mostly arising from the neural crest, with type I and type II being the most frequent. While type I is tightly associated to PAX3 mutations, WS type II (WS2) remains partly enigmatic with mutations in known genes (MITF, SOX10) accounting for only 30% of the cases. We performed exome sequencing in a WS2 index case and identified a heterozygous missense variation in EDNRB. Interestingly, homozygous (and very rare heterozygous) EDNRB mutations are already described in type IV WS (i.e., in association with Hirschsprung disease [HD]) and heterozygous mutations in isolated HD. Screening of a WS2 cohort led to the identification of an overall of six heterozygous EDNRB variations. Clinical phenotypes, pedigrees and molecular segregation investigations unraveled a dominant mode of inheritance with incomplete penetrance. In parallel, cellular and functional studies showed that each of the mutations impairs the subcellular localization of the receptor or induces a defective downstream signaling pathway. Based on our results, we now estimate EDNRB mutations to be responsible for 5%–6% of WS2.

Altered inhibitory control and increased sensitivity to cross-modal interference in tinnitus during auditory and visual tasks.

Tinnitus is the perception of sound in the absence of external stimulus. Currently, the pathophysiology of tinnitus is not fully understood, but recent studies indicate that alterations in the brain involve non-auditory areas, including the prefrontal cortex. In experiment 1, we used a go/no-go paradigm to evaluate the target detection speed and the inhibitory control in tinnitus participants (TP) and control subjects (CS), both in unimodal and bimodal conditions in the auditory and visual modalities. We also tested whether the sound frequency used for target and distractors affected the performance. We observed that TP were slower and made more false alarms than CS in all unimodal auditory conditions. TP were also slower than CS in the bimodal conditions. In addition, when comparing the response times in bimodal and auditory unimodal conditions, the expected gain in bimodal conditions was present in CS, but not in TP when tinnitus-matched frequency sounds were used as targets. In experiment 2, we tested the sensitivity to cross-modal interference in TP during auditory and visual go/no-go tasks where each stimulus was preceded by an irrelevant pre-stimulus in the untested modality (e.g. high frequency auditory pre-stimulus in visual no/no-go condition). We observed that TP had longer response times than CS and made more false alarms in all conditions. In addition, the highest false alarm rate occurred in TP when tinnitus-matched/high frequency sounds were used as pre-stimulus. We conclude that the inhibitory control is altered in TP and that TP are abnormally sensitive to cross-modal interference, reflecting difficulties to ignore irrelevant stimuli. The fact that the strongest interference effect was caused by tinnitus-like auditory stimulation is consistent with the hypothesis according to which such stimulations generate emotional responses that affect cognitive processing in TP. We postulate that executive functions deficits play a key-role in the perception and maintenance of tinnitus.

Dynamic Posturography (Equitest): Outcome after Vestibular Neurotomy or Acoustic Neuroma Removal

Objectives: This study has two aims. First, we analyze the results of dynamic computerized posturography (Equitest) achieved by patients who have undergone acoustic neuroma removal or vestibular neurotomy. The examination is performed during the preoperative assessment and at several postoperative consultations. Secondly, after analyzing the results, we evaluate the interest of this type of examination for such patients during preoperative assessment and postoperative follow-up. Patients: 25 patients underwent acoustic neuroma removal and 8 vestibular neurotomy from June 1996 until September 1997. All patients included in the study underwent dynamic posturography follow-up. The schema proposed was an examination before surgery and then 10 days and 1 and 3 months after the operation. Not all patients underwent all examinations (it is a retrospective study). Method: Retrospective case review. Results: 50% of the patients (n = 8) who underwent vestibular neurotomy achieved a normal score at the sensory organisation test (SOT) of the Equitest within the first 6 postoperative weeks. 60% of the patients (n = 25) undergoing acoustic neuroma removal developed a central vestibular compensation 3 months after surgery. Two patients developed an inadequate balance strategy with excessive visual dependence detected by the SOT. Conclusions: According to our experience, the SOT is a useful examination during the follow-up period of patients who have undergone neurootologic surgery. It provides information about the progress of postoperative central vestibular compensation. The dynamic posturography also detects inadequate balance strategies, therefore, allowing a personalized vestibular reeducation adapted to each patient.

A key role of the prefrontal cortex in the maintenance of chronic tinnitus: An fMRI study using a Stroop task

Introduction Since we recently showed in behavioural tasks that the top-down cognitive control was specifically altered in tinnitus sufferers, here we wanted to establish the link between this impaired executive function and brain alterations in the frontal cortex in tinnitus patients. Method Using functional magnetic resonance imaging (fMRI), we monitored the brain activity changes in sixteen tinnitus patients (TP) and their control subjects (CS) while they were performing a spatial Stroop task, both in audition and vision. Results We observed that TP differed from CS in their functional recruitment of the dorsolateral prefrontal cortex (dlPFC, BA46), the cingulate gyrus and the ventromedial prefrontal cortex (vmPFC, BA10). This recruitment was higher during interference conditions in tinnitus participants than in controls, whatever the sensory modality. Furthermore, the brain activity level in the right dlPFC and vmPFC correlated with the performance in the Stroop task in TP. Conclusion Due to the direct link between poor executive functions and prefrontal cortex alterations in TP, we postulate that a lack of inhibitory modulation following an impaired top-down cognitive control may maintain tinnitus by hampering habituation mechanisms. This deficit in executive functions caused by prefrontal cortex alterations would be a key-factor in the generation and persistence of tinnitus.

European 17 countries consensus endorses more approaches to APD than reported in Wilson 2018

It was a pleasure reading Wilson’s paper: “Evolving the concept of APD” (2018) insightful article on different approaches to APD set to promote understanding of the disorder. The interpretation of ...

The development of a new questionnaire for cognitive complaints in vertigo: the Neuropsychological Vertigo Inventory (NVI)

Vertigo patients frequently complain of emotional and associated cognitive problems, yet currently, there is no satisfactory questionnaire to measure these associated problems. In the present paper, we propose a new internet-based Neuropsychological Vertigo Inventory (NVI; French) that evaluates attention, memory, emotion, space perception, time perception, vision, and motor abilities. The questionnaire was created using four steps: (1) open interviews with patients suffering from vertigo; (2) semi-structured interviews with an analysis grid to quantify and define the various cognitive and emotional problems reported by the patients; (3) a first version of an internet questionnaire tested on 108 vertigo participants; and (4) the selection of subscale items using principal component analyses (PCA). From the development phase, the revised NVI was composed of seven subscales, each with four items (28 items). In the validation phase, Cronbach’s alphas were performed on the revised NVI for total and each subscale score, and to test extreme groups validity, the analyses of covariance (ANCOVAs) taking into account age were performed between 108 vertigo and 104 non-vertigo participants. The Cronbach’s alphas showed good to satisfactory coefficients for the total and for all subscale scores, demonstrating acceptable reliability. The extreme groups validity analyses (ANCOVAs) were reliable for the total scale and for four subscales. Supplementary analyses showed no effect of hearing difficulties and an inverse age effect for attention and emotion subscales, with reduced problems with increased age in the vertigo participants. The NVI provides a useful new questionnaire to determine cognitive and emotional neuropsychological complaints that are associated with vertigo.