Audiologic manifestations of patients with post-treatment Lyme disease syndrome.

OBJECTIVE: The purpose of this study was to characterize auditory function in patients diagnosed with post-treatment Lyme disease syndrome (PTLDS). DESIGN: Eighteen patients with PTLDS were evaluated and compared to a normal population. Evaluations consisted of pure tone and speech thresholds, word recognition (WRS), acoustic immittance battery, auditory brain stem response (ABR), and loudness discomfort level (LDL). Both seropositive and seronegative patients were evaluated. Audiologists were blinded to patient status. RESULTS: Forty four percent of the patients had one or more abnormal pure tone thresholds compared to gender- and age-adjusted norms. Thirty-one percent showed abnormally reduced LDLs, and 17% had abnormal acoustic reflexes at one or more frequencies. CONCLUSIONS: This paper catalogs previously unstudied long-term auditory system sequelae resulting from PTLDS. Our most significant finding was the dramatically reduced loudness tolerance in the presence of either normal or minimally impaired hearing. The clinician is encouraged to consider PTLDS when confronted with these or similar findings in patients having history of Borrelia burgdorferi infection and continued complaints.

The Stickler syndrome: genotype/phenotype correlation in 10 families with Stickler syndrome resulting from seven mutations in the type II collagen gene locus COL2A1.

PURPOSE: To evaluate a cohort of clinically diagnosed Stickler patients in which the causative mutation has been identified, determine the prevalence of clinical features in this group as a whole and as a function of age, and look for genotype/phenotype correlations. METHODS: Review of medical records, clinical evaluations, and mutational analyses of clinically diagnosed Stickler patients. RESULTS: Patients with seven defined mutations had similar phenotypes, though both inter- and intrafamilial variability were apparent and extensive. The prevalence of certain clinical features was a function of age. CONCLUSION: Although the molecular determination of a mutation can predict the occurrence of Stickler syndrome, the variability observed in the families described here makes it difficult to predict the severity of the phenotype on the basis of genotype.

Auditory function associated with Col11a1 haploinsufficiency in chondrodysplasia (cho) mice.

Heterozygosity for mutations in the fibrillar collagen gene COL11A1 causes sensorineural hearing loss in patients with Stickler syndrome or Marshall syndrome. Chondrodysplasia (cho) is a functional null allele of Col11a1 that causes lethal chondrodysplasia in cho/cho newborn mice, and osteoarthritis in cho/+ heterozygotes. To determine if Col11a1 haploinsufficiency causes hearing loss in cho/+ mice, auditory brainstem response (ABR) thresholds were measured at 2, 4, 6, 8 and 10 months of age. There was no difference in ABR thresholds for click and tone burst stimuli between cho/+ and +/+ mice at all ages. In contrast to the conclusion of a previous report, our results indicate that Col11a1 haploinsufficiency does not cause significant hearing loss on the C57BL/6 strain background. We conclude that Stickler syndrome and Marshall syndrome mutations in COL11A1 cause hearing loss via dominant negative effects upon wild-type fibrillar collagen polypeptides in the extracellular matrices of the cochlea.

Auditory manifestations of Keratitis-Ichthyosis-Deafness (KID) syndrome.

OBJECTIVE: Evaluation of the auditory manifestations of Keratitis-Ichthyosis-Deafness (KID) syndrome, a rare genodermatosis characterized by follicular hyperkeratosis, vascularizing keratitis, and congenital hearing loss. STUDY DESIGN: Five individuals with sporadic KID syndrome were evaluated in the outpatient audiology clinic at the Warren Grant Magnuson Clinical Center of the National Institutes of Health. METHODS: Audiologic examinations included pure-tone audiometry, speech audiometry, and middle ear immittance testing. Auditory brainstem responses and otoacoustic emissions were analyzed in 2 subjects. RESULTS: Four subjects had prelingual, bilateral, profound sensorineural hearing loss, whereas the fifth subject had significant residual hearing that exhibited no progression on serial audiograms. All 5 subjects had a history of non-erosive keratosis obturans and cutaneous cysts in the external ear canals that prevented continuous use of ear molds. CONCLUSIONS: The sensorineural hearing loss in KID syndrome is generally prelingual and profound. This combination of auditory and cutaneous phenotypes is similar to those previously reported for KID syndrome. KID syndrome presents a difficult challenge for communication rehabilitation because keratitis may impair the perception of sign and spoken language, and the cutaneous manifestations routinely curtail use of external amplification devices.