Auditory neuropathy in Brown-Vialetto-Van Laere syndrome due to riboflavin transporter RFVT2 deficiency.

AIM: Mutations in the genes encoding the riboflavin transporters RFVT2 and RFVT3 have been identified in Brown-Vialetto-Van Laere syndrome, a neurodegenerative disorder characterized by hearing loss and pontobulbar palsy. Treatment with riboflavin has been shown to benefit individuals with the phenotype of RFVT2 deficiency. Understanding the characteristics of hearing loss in riboflavin transporter deficiency would enable early diagnosis and therapy. METHOD: We performed hearing assessments in seven children (from four families) with RFVT2 deficiency and reviewed results from previous assessments. Assessments were repeated after 12 months and 24 months of riboflavin therapy and after cochlear implantation in one individual. RESULTS: Hearing loss in these individuals was due to auditory neuropathy spectrum disorder (ANSD). Hearing loss was identified between 3 years and 8 years of age and progressed rapidly. Hearing aids were not beneficial. Riboflavin therapy resulted in improvement of hearing thresholds during the first year of treatment in those with recent-onset hearing loss. Cochlear implantation resulted in a significant improvement in speech perception in one individual. INTERPRETATION: Riboflavin transporter deficiency should be considered in all children presenting with an auditory neuropathy. Speech perception in children with ANSD due to RFVT2 deficiency may be significantly improved by cochlear implantation.

Steroid-dependent sensorineural hearing loss in a patient with Charcot-Marie-Tooth disease showing auditory neuropathy.

Charcot-Marie-Tooth disease (CMT) is the most common form of hereditary sensorimotor neuropathy and sometimes involves disorders of the peripheral auditory system. We present a case of steroid-dependent auditory neuropathy associated with CMT, in which the patient experienced 3 episodes of acute exacerbation of hearing loss and successful rescue of hearing by prednisolone. An 8-year-old boy was referred to the otolaryngology department at the University Hospital. He had been diagnosed with CMT type 1 (demyelinating type) at the Child Neurology Department and was suffering from mild hearing loss due to auditory neuropathy. An audiological diagnosis of auditory neuropathy was confirmed by auditory brainstem response and distortion-product otoacoustic emissions. At 9 years and 0 months old, 9 years and 2 months old, and 10 years and 0 months old, he had experienced acute exacerbations of hearing loss, each of which was successfully rescued by intravenous or oral prednisolone within 2 weeks. Steroid-responsive cases of CMT have been reported, but this is the first case report of steroid-responsive sensorineural hearing loss in CMT. The present case may have implications for the mechanisms of action of glucocorticoids in the treatment of sensorineural hearing loss.

[The curative effect analysis of combined medical therapy for auditory neuropathy spectrum disorder].

OBJECTIVE: To investigate the efficacy of combined medical treatment on auditory neuropathy spectrum disorder and the effect of related factors on the prognosis. METHOD: Eleven cases (22 ears) diagnosed as auditory neuropathy spectrum disorder using multiple criteria including pure tone auditory threshold, impedance audiometry, acoustic reflexes, distortion products otoacoustic emission (DPOAE) and auditory brainstem response (ABR) were subjected to combined medical treatment . Eleven auditory neuropathy spectrum disorder patients diagnosed during the corresponding period but refused treatment were selected as control group. The change of pure tone auditory threshold and speech discrimination score after treatment or follow-up were evaluated for both 2 groups, and the relationship between the patients' gender, age, accompanying symptoms and curative effect were also analyzed. Data were analyzed by SPSS 19.0 statistical software using pared-sample t-test, independent-sample test and Pearson's chi-square test. RESULT: The effective rate of combined medical therapy was 59.09% (13/22) in the therapy group. PTA levels before and after-treatment were (53.92 +/- 18.86) dB HL and (47.44 +/- 14.98) dB HL respectively in 22 ears with the combined medical therapy, the improvement of which showed statistically significance (t = 5.20, P < 0.05). No obvious hearing change was noted in the 11 patients who refused therapy (P > 0.05). Speech discrimination score before and after-treatment were (29.20 +/- 25.80)% and (41.60 +/- 22.90)% respectively for the treatment group. The average improvement of speech discrimination score was (12.40 +/- 13.80)% with statistically significant difference (t = 4.02, P < 0.05). Patients accompanied with tinnitus had relatively poorer effect compared with individuals without tinnitus (t = -3.85, P < 0.05). Age is negatively correlated with the prognosis (r = -6.72, P < 0.05). Gender had no effect on the prognosis (P > 0.05). CONCLUSION: The combined medical therapy with glucocorticoids helps improving the pure tone auditory threshold and speech discrimination score of auditory neuropathy spectrum disorder. In light of our findings we support the combined medical therapy as an option for patients with auditory neuropathy spectrum disorder.

Cobalt, chromium and molybdenum ions kinetics in the human body: data gained from a total hip replacement with massive third body wear of the head and neuropathy by cobalt intoxication.

INTRODUCTION: A patient with a total hip replacement developed optic, acoustic and peripheral neuropathy from metal ions intoxication, due to the wear products released from the prosthesis. Subsequently the kinetics of the metal ions was studied. MATERIALS AND METHODS: Massive wear and acute intoxication allowed a study of the metal ions kinetics and of EDTA treatment. RESULTS: Plasma and other organic fluids were saturated by each of the metal ions released from the exposed surface according to the solubility of each ion; a larger fraction of Co ions was bound within red cells, while the plasmatic fraction appeared more movable. In a patient with a prosthesis subjected to wear, the ions released are from the prosthetic and from the debris surface (spread in the body). The latter is a function of the number and size of particles. DISCUSSION: Revision of the prosthesis from the point of view of the metal ions kinetics corresponded to a reduction of the releasing surface because of debris washed out by irrigation and tissue excision; however, the metal particles spread by lymphatic circulation continued to release ions even though the source of wear had been removed. Early diagnosis of high metal wear can be ascertained with mass spectrometry and after revision high levels of metal ions can only be reduced with repeated chelating treatment. It is preferable not to revise fractured ceramic components with a polyethylene-metal articulation.

Auditory processing and learning/memory following erythropoietin administration in neonatally hypoxic-ischemic injured rats.

BACKGROUND: Hypoxia-ischemia (HI) is a common injury arising from prematurity/complications at birth and is associated with later language, auditory, and learning impairments. OBJECTIVE: To investigate the efficacy of two doses (300 or 1000 U/kg) of Erythropoietin (Epo) in protecting against neuropathological and behavioral impairments associated with HI injury in rats. METHODS: HI injury (right carotid artery cauterization and 120 min of 8% O(2)) was induced on postnatal day 7 (P7) and Epo or saline was administered i.p. immediately following the procedure. Auditory processing and learning/memory were assessed throughout development. RESULTS: Both doses of Epo provided behavioral protection following HI injury. Rats given 300 or 1000 U/kg of Epo performed significantly better than HI animals on a short duration complex auditory processing procedure, on a spatial Morris water maze assessing spatial learning/reference memory, and a non-spatial water maze assessing associative learning/reference memory. CONCLUSIONS: Given Epo's extant clinical use (FDA approved for pediatric patients with anemia secondary to prematurity), the current results add to a growing body of literature supporting the use of Epo as a potential protective agent for neurological and behavioral impairments following early HI injury in infants.

[Pharmacopuncture in combined treatment of children with neurosensory hypoacusis]. / Primenenie farmakopunktury v kompleksnom lechenii detei s sensonevral'noi tugoukhost'iu.

Pharmacopuncture treatment (cerebrolysin, cavinton, prozerin) was given to 120 children with neurosensory hypoacusis aged 4-15 years. The treatment consisted of 3 courses 10 days each with 7-10-day interval. The drugs were injected in the dose 0.1 ml in biologically active points according to the original technique. The treatment lowered tonal thresholds more than by 15 dB in 36% children. Speech intelligibility increased, head ache and nose in the ears relieved in 85% cases. Adaptation to the hearing aid was positive. Clinical evidence was confirmed by REG picture indicating normalization of hemodynamics. Pharmacopuncture is a promising method in the treatment of children with neurosensory hypoacusis.