Effects of stimulation rates on Cantonese lexical tone perception by cochlear implant users in Hong Kong.

High, moderate and low stimulation rates of 1800, 800 and 400 pulse per second (pps)/channel, respectively, were used to test the effects of stimulation rates on the discrimination and identification of Cantonese lexical tones in 11 Chinese post-lingually deafened adults with cochlear implants (CIs). The subjects were implanted with the MED-EL Combi 40+ CI system. They were randomly assigned to each of the stimulation rate conditions according to an ABC design. In both the Cantonese lexical tone perception tests, the subjects reached the highest scores in the high-stimulation-rate condition, and the lowest scores in the low-stimulation-rate condition (P < 0.01). Post hoc comparisons between different stimulation rates did not yield consistent results. This study demonstrated that the maximum stimulation rate of 1800 pps/channel could be an 'optimal' stimulation rate and an informed choice of parameter for the benefit of Cantonese-speaking CI users in lexical tone perception.

Relationship of motor and cognitive abilities to functional performance in stroke rehabilitation.

This study explored the relationships between the motor and cognitive abilities, and the functional performance of patients with stroke. Motor and cognitive abilities were measured by the Fugl-Meyer Assessment (FMA) and the Neurobehavioural Cognitive Status Examination (NCSE), and functional performance was measured by the Functional Independence Measure (FIM). All assessments were conducted at admission, after 2 and 4 weeks, and at discharge. A total of 37 patients with first stroke at mean age 62.3 years (SD=5.4) participated in the study. Results indicated that the lower extremity and balance scores on the FMA were highly correlated with the FIM (motor subscale) on all occasions (r = 0.65--0.92), whereas upper extremity and hand scores on the FMA were moderately correlated (r = 0.53--0.73). Cognitive abilities such as judgement, comprehension and repetition had moderate positive relationships with functional performance (r = 0.35--0.62). Consistent with previous studies, motor functional performance at discharge was best predicted by balance and judgement abilities at admission, or lower extremity abilities and balance at 2-weeks, or lower extremity and repetition abilities at 4-weeks. At admission, lower extremity and cognitive abilities were found to be the best predictors of patients' length of stay. The results from this study substantiated the fact that motor impairment, including balance and lower limb ability, strongly accounts for functional recovery in the rehabilitation of patients with stroke staying in hospital. This study provided good data for rehabilitation professionals on monitoring neurological recovery, especially balance and lower extremity abilities, to enhance the functional recovery of patients after stroke. More intensive intervention in these aspects should be provided to patients to promote more efficient functional regain and shortening of the length of stay.

Hirschsprung's disease: a more generalised neuropathy?

BACKGROUND/PURPOSE: Aberrant neural crest migration is implicated in the pathogenesis of hindgut aganglionosis in Hirschsprung's disease (HSCR). Neural crest progenitors also give rise to a variety of cell types outside the gut, including nerves of the inner ear and peripheral nervous system. This study aims to determine whether such nerves are also affected in HSCR. METHODS: Pure tone audiometry and oto-acoustic emission tests were performed on 53 patients with Hirschsprung's disease and 28 age-matched controls. Forty-two children with Hirschsprung's disease and 30 age-matched controls also underwent neurologic evaluation, including quantitative peripheral tests of sensory function. RESULTS: Moderate to severe sensorineural hearing loss (1 profound [Waardenburg syndrome] and 3 high frequency) was detected in 4 children (8%) from the Hirschsprung's group. Abnormal (absent or reduced) oto-acoustic emission was detected in 77 of 102 ears (41 of 51 patients) in the HSCR group and 8 out of 48 ears (6 of 24 children) in the control group (75% v 17%; P<.0001). Two HSCR children had marked abnormalities on tests of peripheral nerve function. Significantly higher thresholds for vibration sensation were detected in HSCR versus controls (P<.05). CONCLUSION: Hirschsprung's disease may have a more generalised neuropathy than just that involving the affected bowel.

Correlation of pure tone audiogram results and hearing benefit of tympanoplasty for chronic suppurative otitis media.

The aim of this study was to evaluate the correlation between pure tone audiogram results and the subjective sensation of hearing benefit of patients who had tympanoplasty for chronic suppurative otitis media. This is a prospective study of 115 patients who had tympanoplasty between 1992 and 1994. The outcome, including a pure tone audiogram and the subjective sensation of hearing benefit, was evaluated at 1 year after operation. There were 63 (55%) patients with subjective hearing benefit after the tympanoplasty. The subjective sensation of hearing benefit correlated with the magnitude of the air conduction (AC) threshold reduction, and increased from 39% for an AC reduction of less than or equal to 10 dB to 100% for an AC reduction of more than 30 dB. The effect of the interaural AC threshold difference on the subjective sensation of hearing was not significant; improvement was felt by 92% of patients when the operated ear became the better hearing ear, and by 73% of patients when the operated ear remained the worse hearing ear. There was considerable discrepancy between the subjective hearing benefit and the pure tone audiogram results. A combination of parameters, including the air-bone gap, the AC threshold, and the subjective hearing change, is recommended in reporting the results of tympanoplasty.

Chinese tonal language rehabilitation following cochlear implantation in children.

Cantonese language rehabilitation in 28 prelingually deaf children who underwent cochlear implantation was evaluated. All patients were implanted with multichannel devices and the operations went smoothly. They all had improved scores on audiological assessments and speech perception tests. The speech evaluation tests included the recognition of sounds, vowels, consonants and tone. Sentence recognition and story comprehension were both improved after training for 2 years. Cochlear implantation is a useful measure for the speech rehabilitation of prelingually profound deaf children when hearing aids are of no benefit. The multichannel implant device is of clinical significance in the rehabilitation of those patients using tonal language.

Long-term sensorineural hearing deficit following radiotherapy in patients suffering from nasopharyngeal carcinoma: A prospective study.

BACKGROUND: This was a prospective study to evaluate the effect of radical external irradiation on inner ear function after treatment of nasopharyngeal carcinoma. METHODS: Pure tone audiograms were performed at regular intervals before, after, and up to 4.5 years following completion of radiotherapy. RESULTS: Two hundred ninety-four patients (526 ears) were included. Within 3 months after radiotherapy, deterioration of bone conduction threshold at 4 kHz and pure tone average (average of 0.5 kHz, 1 kHz, and 2 kHz) were noted in 164 ears (31%) and 75 ears (14%), respectively. Patients older than 50 years and ears with threshold below 60 dB at 4 kHz before radiotherapy were significant factors (p < 0.01 and p < 0. 001) associated with a 4 kHz loss. In 40% of these ears, recovery was evident at 2 years. With follow-up for 4.5 years, the probability of significant threshold deterioration increased with time. CONCLUSION: Sensorineural hearing loss started soon after radiotherapy. Early changes could be reversible while the probability of persistent hearing loss continued to increase.

Constructing options for health care reform in Hong Kong.

The Harvard Report, published in April 1999 for public consultation in Hong Kong, proposed a fundamental restructuring in its health care delivery and financing systems. The Report claims to be evidence-based in its approach (Hsiao et al., 1999a). While 'evidence' has been widely collected by the consultancy team through surveys, consultations and focus groups, the recommendations put forth are not value-free. They carry clear ideological preferences. The value assumptions and ethical presuppositions underlying the report are discussed in this paper. The Harvard consultancy study is in favor of a positive government role in regulation and control, a single central body to administer compulsory health insurance for all citizens, and a purchaser-provider split to induce competition. Such preference is based on pre-existing ideology and generic health care management concepts, which are still in the experimental phase internationally. While value and ideology are inevitable factors in any policy choice, the challenge is to lay these values open for reflection and public debate. For Hong Kong, the challenge is also to take on local substantive issues in health care and deal with them head-on, rather than putting hope in a universal, generic solution.

Sensorineural hearing loss in patients treated for nasopharyngeal carcinoma: a prospective study of the effect of radiation and cisplatin treatment.

PURPOSE: The pattern of sensorineural hearing loss (SNHL) after primary treatment for nasopharyngeal carcinoma (NPC) was studied, and the effect of cisplatin, radiotherapy does, and fractionation were evaluated. METHODS AND MATERIALS: One hundred thirty-two patients, 227 ears, and 1100 audiogram reports were analyzed. Radiotherapy dose ranged from 59.5 to 76.5 Gy. Fifty-two patients received preirradiation cisplatin, total dose 100-185 mg/m(2). Serial postirradiation bone conduction thresholds at 0.5 kHz, 1 kHz, 2 kHz, and 4 kHz were compared with pretreatment thresholds at respective frequencies. Increase of at least 15 dB was considered as significant and was further grouped as transient or persistent SNHL. Univariate and multivariate analyses were performed to identify predicting factors for persistent SNHL. RESULTS: At median follow-up of 30 months, 24.2% of ears developed persistent SNHL. High frequency was more affected than low frequencies, 22 vs. 5.3%. Males were more affected than females, 29.4 vs. 15.5%, p = 0.0132. Incidence of persistent SNHL increased with age, with 0, 17.2, and 37.4% of patients aged under 30, between 30-50 and over 50 affected, respectively, p = 0.0001. High incidence was found in patient with postirradiation serous otitis media (SOM), 46.9%. Chemotherapy with cisplatin and radiation dose or fractionation had no significant effect. Multivariate analysis confirmed age, sex, and postirradiation SOM as significant prognostic factors for persistent SNHL. CONCLUSIONS: Transient and persistent SNHL occurred after radiotherapy, more commonly affecting high frequency. A low dose of preirradiation cisplatin did not increase the risk. A dose fractionation effect of radiotherapy was not confirmed in this study.