RESUMO
OBJECTIVES: To describe the occurrence of both peripheral and central auditory system dysfunction in sickle cell anaemia (SCA) patients and discuss the different mechanisms hypothesised to be responsible for these alterations. METHODS: An electronic search was conducted using PubMed Central® (MEDLINE), LILACS® and Scopus® databases. This systematic review was performed in accordance with the PRISMA statement. Original observational studies that utilised audiological tests for auditory system evaluations in SCA were included. RESULTS: A total of 183 records were found in the databases searched. Twenty-one of these studies met the inclusion criteria. Pooled prevalence of sensorineural hearing loss (SNHL) was 20.5% (CI: 10.3-33%). Retrocochlear involvement was detected with the auditory brainstem response, which assesses integrity of the cochlea, 8th cranial nerve and brainstem structures. In addition, the increase in otoacoustic emission amplitudes in SCA patients indicates changes in cochlear micromechanics and precedes the expression of a detectable cochlear pathology. CONCLUSION: The prevalence of the SNHL is higher than in the general population. Dysfunction of the auditory system may be present in SCA patients, with the most probable mechanism being the presence of circulatory disturbances resulting from the chronic inflammatory state of the disease.
DYSFONCTIONNEMENT DU SYSTÈME AUDITIF DANS L'ANÉMIE FALCIFORME: REVUE SYSTÉMATIQUE ET MÉTA-ANALYSE: OBJECTIFS: Décrire l'apparition de dysfonctionnements du système auditif périphérique et central chez les patients atteints d'anémie falciforme (AF) et discuter des différents mécanismes supposés responsables de ces altérations. MÉTHODES: Une recherche électronique a été effectuée dans les bases de données PubMed Central® (MEDLINE), LILACS® et Scopus® . Cette revue systématique a été réalisée conformément au PRISMA Statement. Des études observationnelles originales utilisant des tests audiologiques pour évaluer le système auditif dans l'AF ont été incluses. RÉSULTATS: Un total de 183 enregistrements ont été trouvés dans les bases de données consultées. Vingt et une de ces études répondaient aux critères d'inclusion. La prévalence poolée de la perte auditive neurosensorielle (SNHL) était de 20,5% (IC: 10,3% à 33%). L'atteinte rétrocochléaire a été détectée avec la réponse du tronc cérébral auditif, qui évalue l'intégrité de la cochlée, du huitième nerf crânien et de la structure du tronc cérébral. De plus, l'augmentation des amplitudes des émissions otoacoustiques chez les patients atteints de l'AF indique des modifications de la micromécanique cochléaire et précède l'expression d'une pathologie cochléaire détectable. CONCLUSION: La prévalence de la SNHL est plus élevée que dans la population générale. Un dysfonctionnement du système auditif peut être présent chez les patients AF, le mécanisme le plus probable étant la présence de troubles circulatoires résultant de l'état inflammatoire chronique de la maladie.
Assuntos
Anemia Falciforme/epidemiologia , Perda Auditiva Neurossensorial/epidemiologia , Adolescente , Criança , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Feminino , Humanos , Masculino , Emissões Otoacústicas Espontâneas/fisiologia , Doenças Retrococleares/epidemiologiaRESUMO
INTRODUCTION: The assessment of cortical excitability (CE) measurements has been increasingly used in neuropsychiatric research. However, there is scant information on the normative values of these measurements, as well as the possible effect of hemisphere laterality, gender and age on these variables. OBJECTIVES: To obtain normative data for CE measurements by transcranial magnetic stimulation, to assess inter-/intra-investigator variability and the influence of sex, age and oral contraception use. METHODS: A sample of 216 healthy volunteers matched according to age and gender was evaluated. Bilateral rest motor thresholds, motor evoked potentials (MEP), intracortical inhibition and facilitation were measured in the first dorsal interosseous muscle area representation of the primary motor cortex with a circular transcranial magnetic stimulation coil delivering biphasic pulses. Normative data were obtained for 200 participants (in a 1:1 male:female ratio) in a balanced proportion between five age groups (18-30; 31-40; 41-50; 51-60; >60 years). Inter/intra-investigator variability was assessed in 20 healthy volunteers in two sessions performed within a 30-minute interval. Measurements were also performed in a subgroup of 16 healthy female volunteers, using oral contraception and during the menstrual phase. RESULTS: Age had a dichotomous effect on CE measurements, providing significantly different normative data for subjects <50 and >50 years old, with smaller MEP's and intracortical inhibition in older individuals. There were no differences between genders or between left and right hemispheres. Also, CE parameters did not significantly differ with use of contraceptive treatment compared to the menstrual phase of the cycle. The inter-/intra-investigator reliability assessment showed some variability that may not be clinically significant. CONCLUSIONS: Age had a non-linear effect on CE. There were non-significant differences between genders, hemispheres or with use of oral contraceptives. There was good inter-/intra-investigator correlation for rest motor thresholds and motor evoked potentials while intracortical inhibition and facilitation had low correlations but acceptable reliability.