Najeh Beltaief

Clinical and genetic analysis of two Tunisian otosclerosis families

Otosclerosis is caused by an abnormal bone homeostasis of the otic capsule resulting in a conductive hearing loss when the free motion of the stapes is compromised. An additional sensorineural hearing loss arises in some patients, most likely due to otosclerotic foci that invade the cochlear endosteum. Otosclerosis is a very common hearing impairment among Caucasians with a prevalence of about 0.3–0.4% among white adults. In the majority of cases, otosclerosis can be considered as a complex disease, caused by both genetic as environmental factors, but autosomal dominant forms of otosclerosis exist. However, families large enough for genetic analysis are very rare and often show reduced penetrance. To date five loci have been reported, but none of the genes have been cloned yet. In this study, we analyzed two new autosomal dominant otosclerosis families from Tunisia, and genotyped them with microsatellite markers for the known loci, the collagen genes COL1A1 and COL1A2, and NOG gene. In the family LK, linkage to all known loci was excluded. However, the family LS shows suggestive linkage to the OTSC3 region on chromosome 6p21.3–p22.3. This result points out that, besides the five reported loci, there must be at least one additional locus for autosomal dominant otosclerosis.

Compound heterozygosity for dominant and recessive GJB2 mutations in a Tunisian family and association with successful cochlear implant outcome.

OBJECTIVES Mutations of GJB2 encoding connexin 26 are the most common cause of hearing loss. They are responsible for up to 50% of ARNSHL. The pathogenic mutations in this gene are generally inherited recessively. Dominant mutations in GJB2 also cause hearing loss, either in isolated non-syndromic form or as part of a syndrome associated with various skin disorders. METHODS We screened a Tunisian child affected by congenital, bilateral, profound, sensorineural hearing loss for mutations in GJB2 gene using PCR and direct sequencing. RESULTS The proband was found to be compound heterozygous for recessive and dominant GJB2 mutations respectively p.V37I (c.109G > A) and p.R143Q (c.428G > A). Surprisingly the hearing mother is a carrier for this dominant GJB2 mutation. This proband underwent a cochlear implant at four years old. The evaluation using APCEI and IT-MAIS tests at six months post implantation indicates a successful cochlear implant outcome since the deaf child began to acquire language abilities and auditory sensation. CONCLUSIONS The p.R143Q mutation was described for the first time in Tunisia. We confirm the low penetrance of this mutation since the proband mother is a carrier despite her normal hearing. We show the effectiveness of cochlear implant to restore the communication abilities and auditory sensation for our patient.

Paralysie faciale périphérique suite à une otite moyenne aiguë

OBJECTS To discuss clinical presentation and therapeutic approaches of facial paralysis in acute otitis media. METHODS We present five cases of facial palsy in children with acute otitis media managed in our ENT department during a period of 12 years (2001-2012). RESULTS The mean age was 14.2 years; sex ratio was 0.66. All patients presented with a facial asymmetry, but only 3 of them had otalgia before the onset of facial asymmetry. The facial palsy delay was 3.3 days. The ear examination showed that the tympanic membrane was congestive in 4 patients, associated with a bulging in 2 patients, and a small perforation in one patient. Our patients presented grade III to IV initial facial palsy according to House and Brackmann staging. Computed tomography scan revealed a dehiscence of the bony facial canal in one patient. Antibiotic therapy associated with intravenous corticosteroids was administered in all patients. All patients underwent a facial kinesis therapy. A progressive improvement of facial palsy was observed in 4 patients and complete recovery of facial function in one case. DISCUSSION Conservative treatment associating intravenous antibiotic and corticosteroids with or without myringotomy is the standard approach.

HLA class I polymorphisms in Tunisian patients with otosclerosis.

Background: Otosclerosis is a common form of hearing impairment among Western-Eurasian adults. The cause of otosclerosis remains unknown. Autoimmune reaction against the otic capsule has been suggested as a possible aetiologic factor in otosclerosis. Aim: The present study is the first report to evaluate the relationship between class I major histocompatibility complex (MHC) genes (HLA-A, HLA-B and HLA-Cw) and genetic susceptibility to otosclerosis in Tunisian patients. Subjects and methods: Fifty unrelated Tunisian patients exhibiting clinical otosclerosis were typed for HLA-A, HLA-B and HLA-Cw antigens and compared with 100 ethnically-matched healthy controls. Results: Increased frequencies of HLA-A*03 (OR = 4.16, Pc < 0.043), HLA-B*35 (OR = 2.76, Pc < 0.043) and HLA-Cw*03 (OR = 4.57, Pc < 0.043) antigens were found in the patients with otosclerosis compared with healthy controls. Individuals with HLA-A*30 (OR = 0.25, Pc < 0.043), HLA-B*51 (OR = 0.11, Pc < 0.043), HLA-Cw*16 (OR = 0.08, Pc < 0.043) and Cw*06 (OR = 0.32, Pc < 0.043) antigens have a protective effect against otosclerosis. Conclusions: In conclusion, the data suggest that a variation in class I HLA antigens could be a genetic factor involved in susceptibility to otosclerosis in the Tunisian population.

Acute Otomastoiditisin Children: Clinical Presentations and Management

Acute mastoiditis (AC) is a serious complication of acute otitis media (AOM) affecting, in most cases, the pediatric population. Diagnosis is usually easy in front of a retro auricular swelling associated to OM. However, this disease may cause significant and even life threatening complications beyond the tympanomastoid system such as peripheral facial nerve palsy, Bezold’s abscess, meningitis, subperiosteal abscess and brain abscess. Management of AC remains controversial raging from conservative treatment in the form of IV antibiotics to more aggressive interventions such as mastoidectomy. This retrospective study represents our experience in the management of AC in the pediatric population. Our purpose was to review and discuss clinical presentations and main treatment modalities of AM.

Imaging of Paranasal Sinus Mucoceles

Introduction: Mucoceles are cystic masses developing after obstruction of the sinus ostium. The symptoms are not specific. Computed Tomography scan (CT scan) and Magnetic Resonance Imaging (MRI) confirm the diagnosis. Objectives: We herein review the radiologic characteristics of mucoceles in CT scan and MRI. Materials and Methods: We report a retrospective study of 43 patients diagnosed with paranasal sinuses mucoceles. CT scans were performed for all patients, but MRI was carried out only in selected cases. Results: Our study was constituted of 27 males and 16 females with a mean age of 47 years. The CT scan appearence of mucoceles were in all cases as a well circumscribed expansile sinus mass with an effect on the neighbor bone structure. This mass was hypodense in 26 cases, isodense in 14 cases and hyperdense in 3 patients. The paranasal sinuses most frequently affected in our series were the fronto-ethmoidal sinuses. The most affected bone eroded was the lamina papiracea. Intracranial extension was seen in four cases. CT scan allowed to predict the cause of mucoceles in some cases and to provide information about anatomic variants. MRI was realized for 15 patients in addition to the CT scan. It allowed to study the extension of mucoceles to the neighboring organs especially orbital and endocranial ones. Conclusion: The presentations of mucoceles on imaging are quite variable. CT scan provides precious information about the location, bone erosion and extension of the mucoceles. MRI is indicated in some cases especially in cases of orbital or cranial extension.