ABSTRACT
OBJECTIVES/HYPOTHESIS: 1) To evaluate the efficacy of, and problems with, intratympanic gentamicin injection (ITG) in medically intractable definite Ménière's disease (MD) and secondary endolymphatic hydrops (EH); and 2) to review the vestibular status and treatment options of intractable vertigo even after ITG. STUDY DESIGN: Retrospective case review and survey. METHODS: 780 patients with definite MD and secondary EH were enrolled. Long-term outcomes and problems of applied treatment options including ITG and exploratory tympanotomy and gentamicin application (ETG) were analyzed. RESULTS: Of the 780 patients, 95 patients received ITG. Class A and B control of vertigo was achieved in 85 (89.5%) patients; two patients were class C and eight patients were class F (ETG: 6; labyrinthectomy: 1; vestibular neurectomy: 1). Among seven patients who received ETG including 1 patient who skipped ITG due to chronic otitis media, five patients improved to class A, showing a 71.4% success rate; and labyrinthectomies were performed subsequently in the two remaining patients. Vertigo was controlled (class A) in all the patients who received labyrinthectomies (n = 4) or vestibular neurectomy (n = 1). Eight patients (8.4%) experienced more than 10 dB worsening, and two patients (2.1%) progressed to bilateral Ménière's disease. CONCLUSION: ITG failed to control vertigo in 10.5% of cases. ETG may be a reasonable option to facilitate the delivery of gentamicin into the inner ear by direct application of gentamicin over the round window and the oval window. Labyrinthectomy and vestibular neurectomy still have roles in the era of ITG.
Subject(s)
Gentamicins/administration & dosage , Meniere Disease/diagnosis , Meniere Disease/drug therapy , Tympanic Membrane/drug effects , Adult , Aged , Cohort Studies , Endolymphatic Hydrops/diagnosis , Endolymphatic Hydrops/drug therapy , Female , Follow-Up Studies , Gentamicins/adverse effects , Hearing Tests , Humans , Injections, Intralesional , Male , Middle Aged , Recurrence , Retrospective Studies , Risk Assessment , Severity of Illness Index , Treatment Outcome , Vertigo/epidemiology , Vertigo/physiopathologyABSTRACT
OBJECTIVES/HYPOTHESIS: To determine the distribution of the number and types of mutant alleles of SLC26A4 and their correlations with hearing phenotypes in Korean bilateral enlargement of vestibular aqueduct (EVA) patients. STUDY DESIGN: Prospective cohort study. METHODS: To determine the number and type of mutant alleles, Sanger sequencing of coding region of SLC26A4 was performed for 56 patients with bilateral EVA who were consecutively recruited. Their correlations with hearing phenotypes were analyzed based on 0.5-, 1-, 2-, and 3-kHz air conduction averages of pure-tone audiometry. RESULTS: Most patients with bilateral EVA (83.9%) carried two mutant alleles of SLC26A4 (M2), and all others (16.1%) had only one detectable mutant allele of SLC26A4 (M1) in the Korean population. There were no cases with zero mutations. p.H723R/p.H723R was the most frequently observed mutant allelic pair (34%), followed by p.H723R/c.919-2A>G (20%). There was no significant difference in hearing threshold, progression, or fluctuation of hearing level between the M1 and M2 groups. However, focusing on the type of mutations exclusively in the M2 group, cases with p.H723R/c.919-2A>G were associated with more frequent progression of hearing loss during the follow-up period. The cases with p.H723R/c.919-2A>G tended to show slightly better hearing than p.H723R homozygotes, although the difference was not statistically significant. There appears to be a different genotype-auditory phenotype correlation among ethnicities. CONCLUSIONS: Our data suggest that the auditory phenotype of Korean bilateral EVA patients is more strongly correlated with the type rather than the number of mutations in SLC26A4. LEVEL OF EVIDENCE: NA.
Subject(s)
Hearing , Membrane Transport Proteins/genetics , Mutation , Vestibular Aqueduct , Vestibular Diseases/genetics , Vestibular Diseases/physiopathology , Adolescent , Adult , Alleles , Asian People , Child , Child, Preschool , Female , Genotype , Humans , Infant , Male , Phenotype , Prospective Studies , Sulfate Transporters , Young AdultABSTRACT
This study provides the first demonstration that central cannabinoids modulate the antinociceptive actions of metabotropic glutamate receptors (mGluRs) on formalin-induced temporomandibular joint (TMJ) nociception. Noxious scratching behavior induced by formalin injection in the TMJ was used as a model of pain. Intracisternal injection of 30mug of WIN 55,212-2, a non-subtype selective cannabinoid receptor agonist, attenuated the number of scratches by 75% as compared with the vehicle-treated group, whereas vehicle alone or 3 or 10 microg of WIN 55,212-2 had no effect. To explore the postulated interaction between central cannabinoid receptors and mGluRs, effects of combined administration of sub-analgesic doses of WIN 55,212-2 and group II or III mGluR agonists were tested. Group II or III mGluRs agonists were administered intracisternally 10 min after intracisternal administration of WIN 55,212-2. Neither 100 nmol APDC, a group II mGluRs agonist, nor L-AP4, a group III mGluR agonist, altered nociceptive behavior when given alone but significantly inhibited the formalin-induced nociceptive behavior in the presence of a sub-threshold dose ( 3microg) of WIN 55,212-2. The ED50 value of APDC or L-AP4 was significantly reduced upon co-treatment with WIN 55,212-2 than in the vehicle-treated group, highlighting the important therapeutic potential of the combined administration of group II or III mGluR agonists with cannabinoids to effectively treat inflammatory pain associated with the TMJ. Potentiating effects of group II or III mGluRs agonists will likely permit the administration of cannabinoids at doses that do not achieve significant accumulation to produce undesirable motor dysfunction.
