A review of the diagnosis and management of sudden hearing loss in the military population

Sudden hearing loss can be both an immediately debilitating and long-term career-threatening condition within the military population. Careful assessment is key, particularly in an environment where heightened occupational risk factors may contribute to or confound diagnoses, and where access to basic investigation may be limited. This article looks at the patient with a new presentation of sudden hearing loss in a military setting and, by providing key features and a structured approach to examination and basic investigation, how to consider key diagnoses through clinical assessment alone. The acute management of sudden sensorineural hearing loss (SNHL) remains a difficult issue, particularly regarding the efficacy of treatment regimes to restore hearing. We have reviewed the evidence to help military medical personnel make well-informed decisions when treating and making occupational assessment of those they have diagnosed with sudden hearing loss.

Noise levels generated within the external auditory canal during microsuction aural toilet and the effect on hearing: a prospective controlled series

OBJECTIVES

To measure the noise generated during suction aural toilet and to determine whether there is any clinically measureable effect on audiometric thresholds.

STUDY DESIGN

Prospective, controlled study with 14 patients.

SETTING

The study was conducted in an aural toilet clinic in a district general ENT department.

PARTICIPANTS

Fourteen patients who attend regularly for suction aural toilet to clear cerumen.

MAIN OUTCOME MEASURES

Live direct measurement of noise levels during treatment. Pre-treatment and post-treatment pure tone audiometry.

RESULTS

Microsuction generated a broadband sound with a peak at 2 kHz. Sound levels peaked at over 120 dB(A) in two patients. We found no evidence of any shift in audiometric thresholds following microsuction aural toilet.

CONCLUSIONS

Microsuction is a noisy procedure that is uncomfortable for some patients. However, it does not appear to be sufficiently noisy to produce a clinically detectable threshold shift. We would suggest that it is safe but that the use of non-suction methods or a fine end may on occasion be preferable to improve patient comfort.

Accurate consent for insertion and later removal of grommets

Each year in the UK over 30 000 patients undergo insertion of grommets. The grommet insertion may cause many problems like persistent otorrhoea, scarred drum, retraction pockets and retention. The grommets may be extruded from the middle ears by the normal epithelial migration mechanism once they have served their purpose. These may become infected and require removal. We have analysed the Department of Health Hospital Episode Statistics relating to the insertion and removal of grommets (ventilation tubes). We have shown that 7.6 per cent of patients who have grommets inserted will have grommets removed.

Cognitive behavioural therapy for tinnitus

BACKGROUND

Tinnitus is an auditory perception that can be described as the experience of sound, in the ear or in the head, in the absence of external acoustic stimulation (not usually audible to anyone else). At present no specific therapy for tinnitus is acknowledged to be satisfactory in all patients. Cognitive behavioural therapy (CBT) uses relaxation, cognitive restructuring of the thoughts and exposure to exacerbating situations in order to promote habituation and may benefit tinnitus patients, as may the treatment of associated psychological conditions.

OBJECTIVES

To assess whether cognitive behavioural therapy is effective in the management of patients suffering from tinnitus.

SEARCH STRATEGY

Our search included the Cochrane ENT Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2006), MEDLINE and EMBASE. The last search date was June 2006.

SELECTION CRITERIA

Randomised controlled trials in which patients with unilateral or bilateral tinnitus as main symptom received cognitive behavioural treatment.

DATA COLLECTION AND ANALYSIS

One review author (PMD) assessed every report identified by the search strategy. The four review authors assessed the methodological quality, applied inclusion/exclusion criteria and extracted data.

MAIN RESULTS

Six trials comprising 285 participants were included. 1.

PRIMARY OUTCOME

subjective tinnitus loudness. CBT compared to a waiting list control group: we found no significant difference (Standardised Mean Difference (SMD) 0.06 (95% CI -0.25 to 0.37)). CBT compared to another intervention (Yoga, Education, Minimal Contact - Education and Education): we found no significant difference (SMD 0.1 (95% CI -0.22 to 0.42)).2.

SECONDARY OUTCOMES

a) Depression. CBT compared to a waiting list control group: we found no significant difference in either group (SMD 0.29 (95%CI -0.04 to 0.63)). CBT compared to another intervention (Yoga, Education and Minimal Contact - Education): we found no significant difference (SMD 0.01 (95% CI -0.43 to 0.45)). b) Quality of life: CBT compared to a waiting list control group: we found a significant difference in favour of CBT versus the waiting list group (SMD 0.7 (95% CI 0.33 to 1.08)). CBT compared to another intervention (Education, Minimal Contact - Education and Education): we also found a significant difference between CBT and the other intervention control group (SMD 0.64 (95% CI 0.29 to 1.00)). There were no adverse/side effects reported in any trial.

AUTHORS' CONCLUSIONS

We did not find a significant difference in the subjective loudness of tinnitus, or in the associated depression. However we found a significant improvement in the quality of life (decrease of global tinnitus severity) of the participants, thus suggesting that cognitive behavioural therapy has an effect on the qualitative aspects of tinnitus and contributes positively to the management of tinnitus.

Interventions for ear discharge associated with grommets (ventilation tubes)

BACKGROUND

The insertion of grommets (also known as ventilation or tympanostomy tubes) is one of the most common surgical procedures performed on children. Postoperative otorrhoea (discharge) is the most common complication with a reported incidence ranging from 10% to 50%. In the UK, many ENT surgeons treat with topical antibiotics/steroid combinations, but general practitioners, mainly through fears of ototoxicity, are unlikely to prescribe these and choose systemic broad-spectrum antibiotics.

OBJECTIVES

1. To identify the most effective non-surgical management of discharge from ears with grommets in place.2. To identify the risks of non-surgical management for this condition (e.g. ototoxicity), and to set benefits of treatment against these risks.

SEARCH STRATEGY

We searched the Cochrane Ear, Nose and Throat Disorders Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2005), MEDLINE (1966 to 2005) and EMBASE (1974 to 2005). We also searched the CINAHL, AMED, LILACS, ISI WEB OF KNOWLEDGE, ISI PROCEEDINGS, mRCT, NNR, ZETOC, KOREAMED, CSA, MEDCARIB, INDMED and SAMED databases. The date of the last search was February 2005.

SELECTION CRITERIA

Randomised controlled trials of adults or children, with any type of grommet and an ear with discharge were included. The trials compared treatment with placebo or one treatment with another. The primary outcome measure was the duration of the discharge.

DATA COLLECTION AND ANALYSIS

The trials were selected independently according to the above criteria by the four reviewers. Differences in opinion over the inclusion of studies were resolved by discussion. The studies were graded using the CASP critical appraisal tool. Analyses were based on the presence of discharge seven days from the onset of treatment.

MAIN RESULTS

There was very little good quality evidence. Four studies were included, all of them investigating different interventions and therefore a meta-analysis was not possible. Only one study demonstrated a significant difference. Oral amoxicillin clavulanate was compared to placebo in 79 patients. The odds of having a discharge persisting eight days after starting treatment was 0.19 (95% CI 0.07 to 0.49) . The number needed to treat to achieve that benefit is 2.5. Participants in both arms of this study also received daily aural toilet. The results will therefore not be applicable to most settings including primary care. No significant benefit was shown in the two studies investigating steroids (oral prednisolone with oral amoxicillin clavulanate and topical dexamethasone with topical ciprofloxacin ear drops), or the one study comparing an antibiotic-steroid combination (Otosporin(R)) drops versus spray (Otomize(R)) (although more patients preferred the spray form).

AUTHORS' CONCLUSIONS

The authors of this review have been unable to identify the most effective intervention or to assess the associated risks. Research is urgently needed into the effectiveness of oral versus topical antibiotics in this group of patients. Clinicians considering antibiotic treatment need to balance any potential benefit against the risks of side effects and antibiotic resistance.

The surgical arrest of post-tonsillectomy haemorrhage: hospital episode statistics

INTRODUCTION

In the consent of patients for tonsillectomy, the risk of returning to theatre for control of postoperative bleeding may be determined from data provided on Hospital Episode Statistics (HES) provided by the Department of Health website.

METHODS

HES data for England from 1998-2002 were used. The numbers of tonsillectomies and of surgical arrest of post-tonsillectomy haemorrhage were considered for children and adults.

RESULTS

Of 220,497 tonsillectomies performed over the 4-year period, 1804 (0.82%) returned to theatre for control of bleeding. However, this was 3.87 times more likely in adults than children (P <0.0001).

CONCLUSION

Adults are nearly four times more likely than children to require surgery for the arrest of post-tonsillectomy haemorrhage.

Quality without tears--practical applications of quality assurance in biotechnology

Expectations of society and funding bodies are increasing the application of quality management systems to research and development. Implementation of such systems needs to be performed sensibly to ensure that the creativity, which is at the core of the research process, can still thrive whilst increasing the visible reliability of outputs. This paper explores the application of quality principles to research and development and provide practical advice on their application.

Cholesteatoma causing facial nerve transection

Cholesteatoma is a well recognized cause of a facial nerve palsy. The usual mechanism for this complication is direct pressure on the nerve. We present a case in which the facial nerve has been transected by cholesteatoma and discuss the possible causes.

Thyroglossal duct remnants

Thyroglossal duct remnants presenting as a lump in the neck are usually called thyroglossal cysts. Meticulous dissection of the cyst and duct, along with the body of the hyoid bone (Sistrunk's operation) is necessary to avoid recurrence. The authors have reviewed the histology of 61 consecutive specimens diagnosed preoperatively as thyroglossal cysts and have found that a true cyst exists in only 46 per cent of cases.

The Great Ormond Street protocol for ward decannulation of children with tracheostomy: increasing safety and decreasing cost

Ward decannulation is the eventual endpoint for the majority of the 40 children managed by tracheostomy at Great Ormond Street Hospital each year. Our previous protocol dictated a 10 day stay in hospital for the 25 children decannulated annually. The aim of this retrospective study was to determine the minimum safe duration for this inpatient stay. In addition, we hoped to identify any factors which might distinguish potentially successful candidates from those likely to fail decannulation. Of 104 patients decannulated between January 1991 and January 1996, complete nursing and medical records were retrieved for 84 children. These notes were retrospectively reviewed and in this group of patients there were 101 attempted decannulations. Information about the initial pathology, interim course and details of the decannulation were collected. Summary statistics were generated. There was no relation between initial pathology or duration of tracheostomy and eventual success or failure of decannulation. Observations by the nursing staff of restlessness, anxiety and recession appeared more frequently in children who eventually failed decannulation. All failures occurred within 48 h of the 24 h trial of tracheostomy blocking. Our results suggest that a safe decannulation protocol can allow discharge after day five.

Detection of herpesviridae in postmortem multiple sclerosis brain tissue and controls by polymerase chain reaction

OBJECTIVE

To test for the presence of herpesviruses in postmortem brain samples from multiple sclerosis patients and controls using polymerase chain reaction.

BACKGROUND

Herpes simplex virus, varicella-zoster virus, Epstein-Barr virus, cytomegalovirus, and human herpesvirus-6 are common viruses capable of persistence and latency. All have been detected in the CNS.

METHODS

Active and inactive plaque tissue, unaffected white matter (WM) and gray matter (GM) from MS cases, and WM and GM controls (Alzheimer's disease, Parkinson's disease and non-neurological disease) were screened for the herpesvirus by PCR.

RESULTS

(1) 37% of the MS cases were positive for herpes simplex virus (HSV). Twenty-eight percent of controls cases were positive for HSV. Forty-one percent of active plaques were positive for HSV in contrast to only 20% of inactive plaques (Sanders et al, 1996). (2) 57% of the MS cases and 43% of the control cases were positive for HHV-6. Thirty-two percent of the active plaques contained HHV-6 compared to 17% of inactive plaques. (3) 43% of the MS cases and 32% of the control cases were positive for VZV. Fourteen percent of the active plaques and 10% of the inactive plaques were positive for VZV. (4) 27% of MS cases and 38% of control cases were positive for EBV. Five percent of the active plaques were positive for EBV and 10% of the inactive plaques were positive. (5) 16% of the MS cases and 22% of the controls were positive for CMV. Nine percent of the active plaques and 10% of the inactive plaques were positive. We also compared MS WM and GM with controls and found no significant difference.

CONCLUSIONS

HSV, HHV-6, and VZV were present in a greater frequency of MS cases compared to controls; however, no statistical differences were noted. The presence of herpesvirus in all tissue makes an etiologic association to MS uncertain. Cellular localization of virus and its relationship to pathology and latency may reveal an association.

Interferonlike factors from antigen- and mitogen-stimulated human leukocytes with antirickettsial and cytolytic actions on Rickettsia prowazekii. Infected human endothelial cells, fibroblasts, and macrophages

Unique features of the primary site of rickettsial replication in typhus fevers, i.e., within the endothelial cells of small blood vessels in tissues, suggest that effector mechanisms, other than those dependent on phagocytosis by activated macrophages with enhanced microbicidal properties, most likely are necessary to explain the cell-mediated immune control of intracellular rickettsial replication in these sites. Theoretically, such mechanisms might involve contact between infected endothelial cells and activated T lymphocyte subpopulations or macrophages or immunologically induced soluble factors or lymphokines. Support for the existence of at least one of these alternative effector mechanisms is presented here for Rickettsia prowazekii. Cultures of human blood leukocytes, upon immunologically specific stimulation with R. prowazekii antigen or nonspecific stimulation with the mitogen phytohemagglutinin, produce soluble factor(s) in the supernatant fluid which, in culture, have (a) an intracellular antirickettsial action on R. prowazekii-infected human endothelial cells, fibroblasts, and macrophages, and (b) a specific cytolytic action on R. prowazekii-infected, but not uninfected bystander, human fibroblasts. Neither action is demonstrable in R. prowazekii-infected chicken embryo fibroblasts. The factor(s) has no direct antimicrobial action on extracellular rickettsiae and is inactivated by heating at 56 degree C for 1 h or by acid treatment at pH 2. Expression of the antirickettsial action requires new host cell messenger transcription and protein synthesis, whereas the cytolytic action does not. The circumstances of production and action and the properties of the factor(s) responsible for the intracellular antirickettsial, and perhaps also the cytolytic action are consistent with those of immune interferon (IFN-gamma).

Penicillin-induced unstable intracellular formation of spheroplasts by rickettsiae

Penicillin G (greater than or equal to 20 micrograms/ml) is rapidly rickettsiacidal for intracellular Rickettsia prowazekii. Light and electron microscopic examinations revealed that penicillin G in culture medium induced a predictable transformation into typical enlarging spheroplasts deficient in the internal, putative peptidoglycan layer of the outer membrane. Under certain conditions, spheroplasts ruptured to discharge contents into host cell cytoplasm and to leave empty shells of defective outer membrane and diffuse amorphous intracytoplasmic antigen. Host cell destruction often accompanied spheroplast rupture. Penicillin G (100 micrograms/ml) caused similar spheroplast formation by Rickettsia rickettsii, but 1,000 micrograms/ml caused neither growth inhibition nor spheroplast formation in Rickettsia tsutsugamushi. The clinical and epidemiological significance of a practical rickettsiacidal drug for the treatment of louse-borne typhus fever is discussed. Practical pharmacologic considerations preclude the use of penicillin for the treatment of typhus or spotted fever.

Some characteristics of heavy and light bands of Rickettsia prowazekii on Renografin gradients

Suspensions of partially purified Rickettsia prowazekii yielded two bands of organisms when centrifuged to equilibrium in Renografin density gradients. Rickettsiae from the lower, heavy band were defective in their infective and metabolic activities, as compared to organisms from the light band. The greater density in Renografin of heavy-banding organisms was due to their lack of permeability barrier to it, as evidenced by the absence of plasmolysis in hypertonic Renografin. In contrast, light-banding rickettsiae were able to exclude Renografin, since they were plasmolyzed in it. The proportion of heavy-banding organisms in a rickettsial suspension was influenced by the growth phase they were in when harvested from infected yolk sacs, as well as by the conditions and media to which they subsequently were exposed. We have concluded that these defective forms arise from the degeneration of light-banding rickettsiae. This separation of two functional classes of rickettsiae in Renografin density gradients has been exploited (i) to increase the uniformity of the suspensions by removing many noninfectious particles and (ii) to determine rapidly the integrity of certain properties of the cytoplasmic membrane of organisms exposed to a variety of conditions.

In vitro studies of Rickettsia-host cell interactions: ultrastructural study of Rickettsia prowazekii-infected chicken embryo fibroblasts

Secondary chicken embryo fibroblasts infected in suspension with the Breinl strain of Rickettsia prowazekii and grown in monolayer culture were examined by both transmission and scanning electron microscopy at specific intervals after infection to study the effects of prolonged intracellular growth on the fine structure of the host cell and the rickettsiae. Cytopathological changes in the infected host cells were not apparent until late in the intracellular growth cycle when the cells began to rupture as a result of a large rickettsial burden. The only recognizable changes in heavily infected cells before lysis were the condensation of the intercristal matrix of some mitochondria and the apparent dissociation of ribosomes from the rough-surfaced endoplasmic reticulum. Although the effects of intracellular growth of rickettsiae on the fine structure of the host cell were rather unremarkable when compared with those imposed by Rickettsia rickettsii in a similar cell system, noticeable morphological changes in the rickettsiae were recognized during the intracellular growth cycle. These changes first became apparent about 40 h postinfection and consisted primarily of an increased electron density of the rickettsiae, the appearance of numerous vacuoles in the rickettsial cytoplasm, and a slight reduction in size of the rickettsiae. Changes of this nature may reflect transitional phases of growth characteristically seen in free-living bacterial cell systems.

DNA and gene therapy: uncoating of polyoma pseudovirus in mouse embryo cells

Pseudovirions (host DNA fragments encapsidated by polyoma virus-coat protein) and polyoma virions are produced after infection of primary mouse embryo cells with polyoma virus. Purified pseudovirions are adsorbed to, and uncoated by, mouse embryo cells. The evidence for this uncoating is based on the conversion by pancreatic DNase of the uncoated pseudovirus DNA from an acid-insoluble to an acid-soluble form. The implications of these experiments to the eventual use of DNA for gene therapy are discussed.