Sensorineural hearing loss caused by mitochondrial DNA mutations: special reference to the A1555G mutation

Mutations in mitochondrial DNA, which are maternally inherited, have been thought to be one of the causes of sensorineural hearing loss. Two mitochondrial mutational sites (A1555G, A7445G) have been reported to be responsible for non-syndromic hearing impairments. The A1555G mutation causes increased susceptibility to aminoglycoside antibiotic-induced hearing loss as well as non-syndromic sensorineural hearing loss. Our wide screening study showed that there may be a great number of subjects within the Japanese population who have the A1555G mutation. Recent reports suggest that high-risk populations may exist throughout the world. The aminoglycoside-induced hearing loss associated with a mitochondrial mutation is commonly bilateral, symmetric, high frequency involved, and is sometimes associated with progressive sensorineural hearing loss.     

Sensorineural hearing loss in patients reaching chronic renal failure in childhood

An analysis of 25 patients with carcinoids of the colon (1,94% of the amount of patients with cancer of the colon) was made. In the recent decade this disease has become 2 times more frequent. Sixteen patients had carcinoids of the rectum, 9 patients had carcinoids of the right half of the colon. Malignant carcinoids were diagnosed in 16 cases, 8 of them being located in the right half. Radical operations are recommended for all carcinoids of the right half of the colon and for tumors of the rectum if more than 2 cm.     

Cephalosporin-induced recurrent aseptic meningitis

A 66-year-old woman had several episodes of aseptic meningitis associated with exposure to cephalexin, cefazolin, and ceftazidime. The cerebrospinal fluid IgG index was elevated, specific IgG-ceftazidime binding was shown, and skin allergy testing with cefazolin provoked a recurrence of meningitis. We postulate an acute hypersensitivity reaction involving an antigen-specific humoral immune response.     

Sensorineural hearing loss in the mdx mouse: a model of Duchenne muscular dystrophy

Sensorineural hearing loss has been identified in several types of muscular dystrophy, but few studies have investigated any relationship between Duchenne muscular dystrophy and hearing. An animal model of Duchenne muscular dystrophy, the mdx mouse, exhibits the same genetic defect as humans. We performed brainstem auditory evoked responses on mdx and control mice in order to assess sensorineural hearing loss. The amplitude and latency of wave I for each animal were measured at increasing sound pressure levels. A significant increase in threshold and a decrease in wave I amplitude were found in the mdx mice. These results indicate that significant sensorineural hearing loss is associated with muscular dystrophy in the mdx mouse. Possible cellular mechanisms contributing to the hearing deficit are presented.     

Prevention of hearing loss in experimental pneumococcal meningitis by administration of dexamethasone and ketorolac

Pneumococcal meningitis remains a significant cause of morbidity, particularly sensorineural hearing loss. Recent literature has suggested that a vigorous host immune response to Streptococcus [corrected] pneumoniae is responsible for much of the neurologic sequelae, including deafness, after bacterial meningitis. This study used a rabbit model of hearing loss in experimental pneumococcal meningitis to evaluate the therapeutic effect of two anti-inflammatory agents, dexamethasone and ketorolac, coadministered with ampicillin. Both adjunctive drugs minimized or prevented sensorineural hearing loss compared with placebo. Dexamethasone, administered 10 min before ampicillin, was particularly effective in minimizing mean hearing threshold change compared with placebo for both clicks (dexamethasone: 6.7-dB sound pressure level [SPL] vs. placebo: 33. 4-dB SPL, P=.0078) and 10-kHz tone bursts (dexamethasone: 8.4-dB SPL vs. placebo: 53.4-dB SPL, P=.0003). These findings support the beneficial role of anti-inflammatory agents in reducing the incidence of hearing loss from pneumococcal meningitis, especially if therapy is instituted early in the course of infection.     

Ramsay Hunt syndrome with aseptic meningitis

A case of Ramsay Hunt Syndrome with characteristic vesicles on the lateral aspect of the left pinna, evidence of infranuclear palsy of the left 7th cranial nerve, associated with same sided loss of taste sensation in the presulcal area of the tongue and perceptive deafness without vestibular disturbances is reported here. The patient had evidence of aseptic meningitis.     

Detection of Leptospira DNA in patients with aseptic meningitis by PCR

Samples of cerebrospinal fluid from 103 patients with aseptic meningitis were tested by PCR for detection of leptospires, and the results were compared with those of the microscopic agglutination test (MAT) and an enzyme-linked immunosorbent assay for detection of immunoglobulin M (ELISA-IgM). Of these samples, 39.80% were positive by PCR and 8.74 and 3.88% were positive by MAT and ELISA-IgM, respectively.     

Chronic neutrophilic meningitis caused by Candida albicans

Meningitis caused by Candida albicans is a very infrequent entity. We present 3 intravenous drug users with chronic neutrophilic meningitis caused by Candida albicans. The clinical, microbiological and radiological features of the 3 patients are reviewed. The interval between the onset of the disease and the diagnosis was long (from 4 to 12 months). Candida albicans was cultured from cerebrospinal fluid (CSF) in the 3 patients. All of them developed hydrocephalus, meanwhile arachnoiditis was disclosed in two. The therapy with amphotericyn, 5-flucytosine and fluconazole produced clinical improvement and the sterilisation of the CSF in all the 3 cases. Clinicians should be aware of this entity because of diagnosis may be delayed in several months.     

Acquisition of noise-induced hearing loss by railway workers

Lead-contaminated water, soil, and paint have been recognized as potential sources of children's lead exposure for decades, but their contributions to lead intake among urban children remain poorly defined. This analysis was undertaken to estimate the relationship of environmental lead exposures to lead intake among a random sample of urban children, adjusted for exposure to lead-contaminated house dust. Analyses of 183 urban children enrolled in a random sample, cross sectional study were conducted. Children's blood and multiple measures of household dust, water, soil, and paint were analyzed for lead, and interviews were conducted to ascertain risk factors for childhood lead exposure. Environmental sources of lead, including house-dust, soil lead, and water lead, were independently associated with children's blood lead levels. In contrast, paint lead levels did not have a significant effect on blood lead levels after adjusting for other environmental exposures. An increase in water lead concentration from background levels to 0.015 mg/L, the current EPA water lead standard, was associated with an increase of 13.7% in the percentage of children estimated to have a blood lead concentration exceeding 10 micrograms/dL; increasing soil lead concentration from background to 400 micrograms/g was estimated to produce an increase of 11.6% in the percentage of children estimated to have a blood lead level exceeding 10 micrograms/dL, and increasing dust lead loading from background to 200 micrograms/ft2 is estimated to produce an increase of 23.3% in the percentage of children estimated to have a blood lead level exceeding 10 micrograms/dL. These data support the promulgation of health-based standards for lead-contaminated dust and soil and the progressive lowering of standards for lead-contaminated water as the definition of undue lead exposure has been modified.     

Cigarette smoking and hearing loss: the epidemiology of hearing loss study

CONTEXT: Clinical studies have suggested that cigarette smoking may be associated with hearing loss, a common condition affecting older adults. OBJECTIVE: To evaluate the association between smoking and hearing loss. DESIGN: Population-based, cross-sectional study. SETTING: Community of Beaver Dam, Wis. PARTICIPANTS: Adults aged 48 to 92 years. Of 4541 eligible subjects, 3753 (83%) participated in the hearing study. MAIN OUTCOME MEASURES: The examination included otoscopy, screening tympanometry, and pure-tone air-conduction and bone-conduction audiometry. Smoking history was ascertained by self-report. Hearing loss was defined as a pure-tone average (0.5, 1, 2, and 4 kHz) greater than 25-dB hearing level in the worse ear. RESULTS: After adjusting for other factors, current smokers were 1.69 times as likely to have a hearing loss as nonsmokers (95% confidence interval, 1.31-2.17). This relationship remained for those without a history of occupational noise exposure and in analyses excluding those with non-age-related hearing loss. There was weak evidence of a dose-response effect. Nonsmoking participants who lived with a smoker were more likely to have a hearing loss than those who were not exposed to a household member who smoked (odds ratio, 1.94; 95% confidence interval, 1.01-3.74). CONCLUSIONS: These data suggest that environmental exposures may play a role in age-related hearing loss. If longitudinal studies confirm these findings, modification of smoking habits may prevent or delay age-related declines in hearing sensitivity.     

Cytokine autoantibodies in multiple sclerosis, aseptic meningitis and stroke

BACKGROUND AND OBJECTIVE: To determine and then compare the time-kill profiles of Enterococcus to antibiotics used for intravitreal therapy. PATIENTS AND METHODS: The time-kill profiles of four endophthalmitis isolates of Enterococcus faecalis, one vancomycin-resistant E. faecalis isolate, and three vancomycin-resistant isolates of E. faecium were determined against vancomycin, amikacin, cefazolin, gentamicin, ampicillin, ciprofloxacin, ceftazidime, clindamycin, and the combinations of vancomycin and amikacin, vancomycin and ceftazidime, vancomycin and gentamicin, vancomycin and ampicillin, cefazolin and gentamicin, and ampicillin and gentamicin. RESULTS: No single antibiotic or combination was bactericidal (defined as 99.9% kill) to all isolates of Enterococcus. Gentamicin was bactericidal to all E. faecalis isolates. None of the tested antibiotics were bactericidal to vancomycin-resistant E. faecium. CONCLUSIONS: The time-kill profiles demonstrated that vancomycin and ceftazidime did not produce a 99.9% kill for E. faecalis in this small study. Gentamicin combined with either cefazolin or ampicillin had somewhat better bactericidal activity and should be considered as an alternative therapy. Novel therapy may be necessary to treat endophthalmitis because of vancomycin-resistant Enterococcus, depending on the susceptibility patterns of the individual isolate and the response to initial therapy.     

The aseptic meningitis syndrome: a complication of posterior fossa surgery

The syndrome of aseptic meningitis is characterized by spiking fever and meningismus. CSF analysis generally shows increased pleocytosis, hypoglycorrhachia, elevated protein and negative cultures. In an earlier series, 70% of children with posterior fossa operations developed the syndrome. In a new review the incidence was slightly more than 30%. The incidence of aseptic meningitis following operation for structural lesions was 44%, which was higher than the tumor group, where the meningitic syndrome was seen in 25% of the children. It is the purpose of this paper to reexamine the impact that steroids have made on the prevalence of the aseptic meningitis syndrome, and to review recent studies that have attempted to distinguish between aseptic and bacterial meningitis.