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No description available.

Four genes for otosclerosis have been mapped to chromosomes 15q25-q26 (OTCS 1), 7q34-q36 (OTCS 2), 6p21.3-22.3 (OTCS 3) and 3q22-24 (OTSC5).  None of the genes have been cloned.  Further, an association between otosclerosis and the type I collagen genes (implicated in osteogenesis imperfecta) has been suggested.  The aim of the present study was to determine whether any further evidence of linkage at the known otosclerosis gene loci exists. Isolated cases, sib-pairs and nuclear families with otosclerosis were ascertained and clinically assessed.  Twenty-five families with otosclerosis were identified in which at least two of their members were affected.  Majority of the families revealed an autosomal dominant pattern of inheritance.  Genetic linkage analysis was carried out in all these families, using microsatellite markers for the known otosclerosis gene loci on chromosomes 15q25-q26, 7q34-q36 and 6p21.3-22.3 and at the COL1A1 and COL1A2 gene loci. Statistically significant exclusion of the COL1A1 locus was demonstrated in one family, as linkage analysis revealed negative LOD scores with values lower than -2.  There was supporting evidence for linkage of the disease in the OTSC1, OTSC2, OTSC3, and COL1A2 loci in few families.  Maximum LOD score value (+1.75) was obtained using multipoint linkage analysis in OTSC2 locus.  However, most of the families revealed negative LOD score values but they were not low enough (<-2) to formally exclude linkage to these regions. Additional techniques used in complex genetics will be required to identify genes involved in the otosclerosis pathology.  Knowledge of these genes could lead to substantial improvements in our ability to diagnose and possible even prevent this type of hearing deterioration.

Ménière’s disease affects 1 in 1000 people and produces vertigo and hearing loss (Morrison, 1981). Endolymphatic sac decompression has been advocated on the basis that endolymphatic hydrops is the underlying pathology. The endolymphatic sac is said to be the terminal dilatation of the membranous labyrinth. It has been proposed that endolymph flows from the semicircular canals and cochlea to the endolymphatic sac. Portman (1927) devised a procedure for ‘decompressing’ the endolymphatic sac by removal of the bone from the posterior cranial fossa to relieve the symptoms of Ménière’s disease. Surgery on the endolymphatic sac remains controversial. Shea (1979) and Bagger-Sjöbäck et al (1990, 1993) have studied the endolymphatic sac using different techniques. There are discrepancies in the results between the two studies. The hypothesis that the endolymphatic sac can be safely approached and decompressed by a transmastoid route was tested. A total of thirteen cadaver heads and ten isolated temporal bones were used. A series of dissections were performed to examine the endolymphatic sac, perform measurements and analyse surgical approaches to the sac. Histological and electron microscopic study were performed. The lumen of the endolymphatic sac was not always identifiable in the dura of the posterior cranial fossa or it frequently lay over the sigmoid sinus. In the dura of the posterior cranial fossa where the endolymphatic sac is located was a thickening of the dura. This thickening was present even in the absence of the endolymphatic sac. The endolymphatic sac can be safely approached by a transmastoid approach, if there is an extraosseous component to the endolymphatic sac. The proximal endolymphatic sac can be approached by posterior cranial fossa route.

Μελετήσαμε σ'αυτή την εργασία τις παραμέτρους των ABR σε 33 ασθενείς με νόσο Meniere (42 άρρωστα αυτιά και 24 υγιή αυτιά των αρρώστων) και τις συγκρίναμε με αντίστοιχες των ABR 20 αυτιών υγιών ατόμων, αναλόγου ηλικίας και φύλου. Σχηματίσαμε δύο ειδών καμπύλες λανθάνοντος χρόνου-έντασης (ΛΧ/Ε) για τα κύματα I, III και V. Η μία με την ένταση του click μετρημένη σε dB HL και η μία σε dB SL. Επίσης σχηματίσαμε τις αντίστοιχες καμπύλες διακυματικού λανθάνοντα χρόνου (ΔΛΧ/Ε). Συγκρίναμε τις καμπύλες αυτές με τις αντίστοιχες των φυσιολογικών ατόμων οπτικά και στατικά στα σημεία 70 dB HL και 70 dB SL. Παρατηρήσαμε σημαντική παράταση του ΛΧ του V των αρρώστων στην HL μέτρηση και μείωση στη μέτρηση SL, σε σχέση με τα φυσιολογικά αυτιά. Ο ΛΧ επίσης των I και III κυμάτων παρουσιάζεται αυξημένος στην πρώτη μέτρηση, ενώ ελαττωμένος στη δεύτερη. Ο ΔΛΧ I-V και στις δυο μετρήσεις παρουσιάζει μια μείωση όχι όμως σημαντική. Οι καμπύλες ΛΧ\Ε για τη μέτρηση HL είναι πιο κάθετες (παρουσιάζουν τη μορφή L) σε σύγκριση με τις φυσιολογικές, ενώ για τη μέτρηση SL είναι παράλληλες με αυτές. Στη συσχέτιση των καμπυλών ABR με το ακουόγραμμα, οι κατηγορίες τωνβ Meniere αυτιών με επίπεδη βαρηκοΐα (FB) και κατερχόμενη βαρηκοΐα (KB), παρουσιάζουν πιο εντυπωσιακά τα περιγραφέντα παραπάνω χαρακτηριστικά των καμπυλών ΛΧ\Ε και για τις δυο κατηγορίες μετρήσεων HL και SL. Εμφανίζουν επίσης σαφέστατα τα χαρακτηριστικά των μεταβολών του ΛΧ, σε όλα τα κύματα και στις δυο μετρήσεις. Όσο μονιμότερες είναι οι βλάβες, τόσο εντονότερα εμφανίζονται οι επιπτώσεις τους στις ABR καμπύλες. Αξιοσημείωτο είναι ότι τα υγιή αυτιά των αρρώστων παρουσιάζουν μια σταθερή σχέση με τα αυτιά μάρτυρες και στις δυο μετρήσεις. Μεταξύ των δυο αυτιών των αρρώστων η διαφορά του ΔΛΧ I-V στις μετρήσεις μας κυμαίνεται μεταξύ 0 και 0.2 msec. Ο λόγος εύρους V\I είναι σταθερά μεγαλύτερος του ένα. / Auditory brainstem responses of 33 patients suffering from Meniere´s disease (42 involved ears) were studied and compared to those of healthy controls. Stimulus intensity was assessed both as sensation loudness (SL) and absolute loudness (HL). Latency of waves I, III and V of the ABR was measured and corresponding latency/ intensity curves were constructed for SL and HL testing. In comparison to controls, latency of wave V latency was significantly prolonged in HL testing, while it was decreased in SL testing. Latency of waves I and III was similarly found increased in HL and decreased in SL testing. Interwave latency between waves I and V was decreased during both HL and SL testing, although this difference was not statistically significant. Latency/intensity curves appear steeper than normal in HL testing, while they are parallel (shifted upward/ downward/to the left/to the right) in SL testing. Notably, ABRs of the healthy ear of Meniere´s patients were similar to those of the involved ear. Difference of interwave latency I-V between the health and involved ear of patients ranged from 0 to 0.2 mse