Balloon dilatation of the Eustachian tube in adult patients with chronic dilatory tube dysfunction: a retrospective cohort study.

OBJECTIVES: The aim of this study is to assess the subjective and objective short-term results and safety of transnasal balloon dilatation of the Eustachian tube (BET) in adult patients with chronic dilatory Eustachian tube dysfunction (ETD). DESIGN: Retrospective cohort study. Data collection was performed preoperatively, 1 and 3 months after BET. SETTING: Tertiary referral hospital. PARTICIPANTS: A cohort of 42 consecutive patients (66 ears). MAIN OUTCOME MEASURES: ETDQ-7 score, bone conduction threshold, air-bone gap, the ability to perform Valsalva's and/or Toynbee's manoeuvre, tympanic membrane and middle ear conditions were collected pre- and postoperatively. Subjective satisfaction and complications were collected postoperatively. RESULTS: The ETDQ-7 score improved significantly from 4.28 to 3.09 1 month postoperatively and from 4.10 to 2.96 3 months postoperatively. Bone conduction thresholds did not differ significantly postoperatively. A significant improvement of air-bone gap was found postoperatively. The tympanic membrane and middle ear condition showed improvement in 62%. Subjective satisfaction 1 and 3 months postoperatively was around 43 and 48%. A small number of minor (self-limiting) complications did occur. CONCLUSIONS: BET has shown to be a safe intervention, which may have a positive effect on objective and subjective indicators for chronic dilatory ETD in adult patients. We observed subjective positive effects in less than half of the patients. For certain indications, there was a measurable positive effect on the findings of the eardrum and ETDQ-7, whereas in other patients it seemed not to have any effect at all. Careful patient selection may improve this success rate. Randomized controlled trials with a prolonged follow-up are required to assess the value of BET in comparison to grommets.

Analysis of failure of voice production by a sound-producing voice prosthesis.

OBJECTIVE: To analyse the cause of failing voice production by a sound-producing voice prosthesis (SPVP). METHODS: The functioning of a prototype SPVP is described in a female laryngectomee before and after its sound-producing mechanism was impeded by tracheal phlegm. This assessment included: perceptual voice evaluation of read-aloud prose by an expert listener; inspection of the malfunctioning SPVP; and aero-acoustical in vivo registrations using a computer-based data acquisition system. RESULTS: Sound-producing voice prosthesis speech is higher pitched, stronger, contains less aperiodic noise and requires a lower airflow rate than the patient's regular tracheoesophageal (TE) shunt speech. Tracheal phlegm caused malfunction of the vibrating silicone lip of the SPVP by causing it to stick to its stainless steel container in an opened position, thereby reducing the SPVP to no more than a regular TE shunt valve from a functional point of view. Tracheal phonatory pressure and dynamic vocal intensity range were not affected by the functional status of the SPVP. CONCLUSIONS: To exploit the advantages an SPVP could offer female laryngectomees with an atonic or severely hypotonic pharyngoesophageal segment, the sound-producing mechanism of the SPVP needs to be less vulnerable to tracheal phlegm.

Assessment of alaryngeal speech using a sound-producing voice prosthesis in relation to sex and pharyngoesophageal segment tonicity.

BACKGROUND: A pneumatic artificial sound source incorporated in a regular tracheoesophageal shunt valve may improve alaryngeal voice quality. METHODS: In 20 laryngectomees categorized for sex and pharyngoesophageal segment tonicity, a prototype sound-producing voice prosthesis (SPVP) is evaluated for a brief period and compared with their regular tracheoesophageal shunt speech. RESULTS: Perceptual voice evaluation by an expert listener and acoustical analysis demonstrate a uniform rise of vocal pitch when using the SPVP. Female laryngectomees with an atonic pharyngoesophageal segment gain vocal strength with the SPVP. Exerted tracheal pressure and airflow rate are equivalent to those required for regular tracheoesophageal shunt valves. However, communicative suitability and speech intelligibility deteriorate by the SPVP for most patients. Tracheal phlegm clogging the SPVP is a hindrance for most patients. CONCLUSIONS: The SPVP raises vocal pitch. Female laryngectomees with an atonic or severely hypotonic pharyngoesophageal segment can benefit from a stronger voice with the SPVP.

Female-pitched sound-producing voice prostheses--initial experimental and clinical results.

In order to improve voice quality in female laryngectomees and/or laryngectomees with a hypotonic pharyngo-oesophageal segment, a sound-producing voice prosthesis was designed. The new source of voice consists of either one or two bent silicone lips which perform an oscillatory movement driven by the expired pulmonary air that flows along the outward-striking lips through the tracheo-oesophageal shunt valve. Four different prototypes of this pneumatic sound source were evaluated in vitro and in two female laryngectomees, testing the feasibility and characteristics of this new mechanism for alternative alaryngeal voice production. In vivo evaluation included acoustic analyses of both sustained vowels and read-aloud prose, videofluoroscopy, speech rate, and registration of tracheal phonatory pressure and vocal intensity. The mechanism proved feasible and did not result in unacceptable airflow resistance. The average pitch of voice increased and clarity improved in female laryngectomees. Pitch regulation of this prosthetic voice is possible with sufficient modulation to avoid monotony. The quality of voice attained through the sound-producing voice prostheses depends on a patient's ability to let pulmonary air flow easily through the pharyngo-oesophageal segment without evoking the low-frequency mucosal vibrations that form the regular tracheo-oesophageal shunt voice. These initial experimental and clinical results provide directions for the future development of sound-producing voice prostheses. A single relatively long lip in a container with a rectangular lumen that hardly protrudes from the voice prosthesis may have the most promising characteristics.

Alternative voice after laryngectomy using a sound-producing voice prosthesis.

OBJECTIVE: To improve the voice quality of female laryngectomees and/or laryngectomees with a hypotonic pharyngoesophageal (PE) segment by means of a pneumatic artificial source of voice incorporated in a regular tracheoesophageal (TE) shunt valve. STUDY DESIGN: Experimental, randomized, crossover trial. METHODS: The new sound source consists of a single silicone lip, which performs an oscillatory movement driven by expired pulmonary air flowing along the outward-striking lip through the TE shunt valve. A prototype of this pneumatic sound source is evaluated in vitro and in six laryngectomees. In vivo evaluation includes speech rate, maximal phonation time, perceptual voice evaluation of read-aloud prose by an expert listener, speech intelligibility measurements with 12 listeners, and self-assessment by the patients. Moreover, extensive acoustical and aerodynamic in vivo registrations are performed using a newly developed data acquisition system. RESULTS: The current prototype seems beneficial in female laryngectomees with a hypotonic PE segment only. For them the sound-producing voice prosthesis improves voice quality and increases the average pitch of voice, without decreasing intelligibility or necessitating other pressure and airflow rates than regular TE shunt speech. Pitch regulation of this prosthetic voice is possible, yet limited. CONCLUSIONS: The mechanism is feasible and does not result in unacceptable airflow resistance. For this new mechanism of alaryngeal voice to become an established technique for postlaryngectomy voice restoration, a voice suitably pitched for male laryngectomees has to be generated and a large part of the melodic and dynamic range of the sound source has to be attainable within physiological airflow rates.

Aero-acoustics of silicone rubber lip reeds for alternative voice production in laryngectomees.

To improve voice quality after laryngectomy, a small pneumatic sound source to be incorporated in a regular tracheoesophageal shunt valve was designed. This artificial voice source consists of a single floppy lip reed, which performs self-sustaining flutter-type oscillations driven by the expired pulmonary air that flows through the tracheoesophageal shunt valve along the outward-striking lip reed. In this in vitro study, aero-acoustic data and detailed high-speed digital image sequences of lip reed behavior are obtained for 10 lip configurations. The high-speed visualizations provide a more explicit understanding and reveal details of lip reed behavior, such as the onset of vibration, beating of the lip against the walls of its housing, and chaotic behavior at high volume flow. We discuss several aspects of lip reed behavior in general and implications for its application as an artificial voice source. For pressures above the sounding threshold, volume flow, fundamental frequency and sound pressure level generated by the floppy lip reed are almost linear functions of the driving force, static pressure difference across the lip. Observed irregularities in these relations are mainly caused by transitions from one type of beating behavior of the lip against the walls of its housing to another. This beating explains the wide range and the driving force dependence of fundamental frequency, and seems to have a strong effect on the spectral content. The thickness of the lip base is linearly related to the fundamental frequency of lip reed oscillation.

Testing the central vestibular functions: a clinical survey.

In vestibular examinations anomalies in the saccade and smooth pursuit tests as well as the fixation suppression after caloric stimulation might indicate central lesions in the vestibular system. Additionally, a high gain in the torsion test is suspicious of cerebellar dysfunction. In this study, 141 patients out of 973 had at least one of these anomalies. For 125 patients we were able to compare the initial findings in the vestibular examination with the final diagnosis by otologists, neurologists and general practitioners. The complaints of 37.6% of the patients with these electronystagmographic (ENG) anomalies appeared to be of central origin. Abnormal saccades, an abnormal smooth pursuit, and an elevated gain in the torsion test were not independently diagnostic for central vestibular disease. The fixation suppression index appeared to be lower for subjects with peripheral vestibular disease. Otologists more often referred their patients to a neurologist if the fixation index was elevated.

Design and in vitro testing of a voice-producing element for laryngectomized patients.

A voice-producing element has been developed to improve speech quality after laryngectomy. The design process started with the formulation of a list of requirements. The lip principle has the best potential for fulfilling the requirements. A numerical model was made to find the optimal geometry of an element based on the lip principle. Extensive in vitro tests were performed to check all requirements. For this a test set-up with realistic acoustic and aerodynamic properties was developed. Results show that the protruding lip length dominates fundamental frequency, cross-sectional area dominates flow resistance and relation between flow and fundamental frequency. Most requirements have been fulfilled; both for males and females a potentially good functioning prototype could be selected. Clinical experiments will be performed to confirm the quality of the voice-producing prosthesis.

Loading dose of quinine in African children with cerebral malaria.

The majority of deaths from cerebral malaria occur within 48 h after admission to hospital. Because of the possibility of inadequate treatment within this period, the use of a loading dose of quinine has been proposed. We reviewed clinical and laboratory data for 113 children with cerebral malaria, who were treated with intravenous quinine, 10 mg/kg every 8 h, at Macha Mission Hospital in rural Zambia. In 1990-1991, 39 children were not given a loading dose of quinine while, in 1992-1993, 74 children received a loading dose of 20 mg/kg. Elevated serum iron levels, as reflected in transferrin saturation, were strongly associated with higher mortality. A loading dose of quinine was associated with faster recovery from coma and enhanced clearance of parasitaemia and fever. The loading dose was also associated with trends to lower mortality and higher haemoglobin levels, but these differences were not statistically significant.