Using a Bone Conduction Hearing Device as a Tactile Aid.

BACKGROUND: With the advent of cochlear implants, tactile aids for the profoundly deaf became obsolete decades ago. Nevertheless, they might still be useful in rare cases. We report the case of a 25-year-old woman with Bosley-Salih-Alorainy Syndrome and bilateral cochlear aplasia. METHODS: After it was determined that cochlear or brainstem implants were not an option and tactile aids were not available anymore, a bone conduction device (BCD) on a softband was tried as a tactile aid. The usual retroauricular position and a second position close to the wrist, preferred by the patient, were compared. Sound detection thresholds were measured with and without the aid. Additionally, three bilaterally deaf adult cochlear implant users were tested under the same conditions. RESULTS: At 250-1000 Hz, sounds were perceived as vibrations above approximately 45-60 dB with the device at the wrist. Thresholds were approximately 10 dB poorer when placed retroauricularly. Differentiation between different sounds seemed difficult. Nevertheless, the patient uses the device and can perceive loud sounds. CONCLUSIONS: Cases where the use of tactile aids may make sense are probably very rare. The use of BCD, placed, e.g., at the wrist, may be useful, but sound perception is limited to low frequencies and relatively loud levels.

Cognition and proprioception in persons with multiple sclerosis and healthy controls: Nascent findings.

BACKGROUND: Although proprioception and cognitive dysfunction are commonly associated with balance impairment and fall risk in persons with multiple sclerosis (MS), the relationship between cognitive functioning and a quantitative measure of proprioception has not been examined in MS. OBJECTIVE: The primary goals of this study were to determine differences in vibratory sensation, a proxy measure of proprioception between persons with MS and healthy controls, examine relationships between cognition and vibration sensation, and determine the contribution of cognitive function and demographics to vibratory sensation between persons with MS and healthy controls. METHODS: One hundred and twenty-two individuals with MS, aged 20-60, with Expanded Disability Status Scale (EDSS) scores ≤5.5 and 48 healthy controls completed reaction time testing, the Stroop test and lower extremity vibratory sensation. RESULTS: Persons with MS performed significantly worse than controls on measures of vibratory sensation (p = 0.001), two-choice reaction time (p = 0.018), and Stroop Incongruent (p < 0.001) Relative Incongruent Score (RIS) (p = 0.047). In MS, average vibration was significantly related to age (p = 0.002), sex (p = 0.038), disease severity (EDSS; p < 0.001), years since diagnosis (p = 0.016), and Stroop Word (p = 0.041). A model with demographics; including age and disease severity, two-choice reaction time, and RIS explained 33.2% of the variance vibratory sensation in persons with MS. CONCLUSIONS: These results provide early evidence for the relation between cognitive functioning and proprioception in persons with MS and add to prior work linking cognitive functioning, postural control and falls in persons with MS. This work provides a basis for future studies combining quantitative measures of proprioception and cognitive and postural control assessment to improve fall prediction.

Assessment of vibratory sensation with a tuning fork at different sites in Japanese patients with diabetes mellitus.

The current study compared the vibratory sensations at different sites, using a retrospective database of 547 Japanese diabetic patients. The vibratory sensation was assessed with a 128-Hz tuning fork at the medial malleolus, the great toe and the fifth toe. The vibratory sensations at different sites were significantly associated with one another (all P < 0.01). The vibratory sensation at one site corresponding to 10 s at another site was calculated to be 9-11 s. Although the vibratory sensations at the three sites had different associations with the pressure sensation and the ankle reflex, they showed similar C-statistics for the impaired pressure sensation and the disappeared ankle reflex. In conclusion, the vibratory sensations at different sites were strongly associated with one another. They would be clinically acceptable alternatives to one another in the assessment of diabetic peripheral neuropathy.

Dependency of temporary threshold shift of vibratory sensation in fingertip on 1/3 octave-band hand-arm vibration exposure period.

OBJECTIVES: To investigate the dependency of temporary threshold shift of vibratoty sensation (TTS(v)) in fingertip on hand-arm vibration exposure period. METHODS: Six healthy students were instructed to grip a vibrating or nonvibrating handle in the experimental room. The gripping force was 40 N. The vibratory sensation threshold at 125 Hz was measured before and after the exposure in the exposed middle fingertip. The exposure vibration was vertical and the 1/3 octave-band vibration with had a central frequency of 200 Hz and an intensity of 39.2 m/s(2). The exposure periods were 8, 15, 30, 60, 120, 240 and 600 s. TTS(v,t) was evaluated as the difference in vibratory sensation threshold between immediately before and t seconds after the exposure. RESULTS: TTS(v) recovered exponentially as in several previous studies and its use enabled us to estimate the time constant and TTS(v,0). TTS(v,0) with vibration exposure was significantly larger than that without it. The regression analysis of the relationship between vibration exposure period (T) and TTS(v,0) (T) for each subject confirmed the good fit of the equation TTS(v,0)(T)=B(0)+B(1) (*)Log(10)(T), where B(0) and B(1) are the calculated constants (adjusted R(2)=0.56-0.87). The time constants did not show such a clear dose effect relationship of exposure period as TTS(v,0). CONCLUSION: The dependency of TTS(v,0) on vibration exposure period was asymptotically proportional to the logarithm of gripping period. To more quantitatively confirm the relationship of the time constants for recovering time course of TTS(v), it may be necessary to improve the measurement method for TTS(v).

Dependency of Temporary Threshold Shift of Vibratory Sensation in Fingertip on 1/3 Octave-Band Hand-Arm Vibration Exposure Period

Objectives: To investigate the dependency of temporary threshold shift of vibratoty sensation (TTSv) in fingertip on hand-arm vibration exposure period. Methods: Six healthy students were instructed to grip a vibrating or nonvibrating handle in the experimental room. The gripping force was 40 N. The vibratory sensation threshold at 125 Hz was measured before and after the exposure in the exposed middle fingertip. The exposure vibration was vertical and the 1/3 octave-band vibration with had a central frequency of 200 Hz and an intensity of 39.2 m/s2. The exposure periods were 8, 15, 30, 60, 120, 240 and 600 s. TTSv, t was evaluated as the difference in vibratory sensation threshold between immediately before and t seconds after the exposure. Results: TTSv recovered exponentially as in several previous studies and its use enabled us to estimate the time constant and TTSv, 0. TTSv, 0 with vibration exposure was significantly larger than that without it. The regression analysis of the relationship between vibration exposure period (T) and TTSv, 0 (T) for each subject confirmed the good fit of the equation TTSv, 0 (T) = B0 + B1 * Log10 (T), where B0 and B1 are the calculated constants (adjusted R2 = 0.56 − 0.87). The time constants did not show such a clear dose effect relationship of exposure period as TTSv, 0. Conclusion: The dependency of TTSv, 0 on vibration exposure period was asymptotically proportional to the logarithm of gripping period. To more quantitatively confirm the relationship of the time constants for recovering time course of TTSv, it maybe necessary to improve the measurement method for TTSv.

Dependency of temporary threshold shift of vibratory sensation in fingertip on 1/3 octave-band hand-arm vibration exposure period

<p><b>OBJECTIVES</b>To investigate the dependency of temporary threshold shift of vibratoty sensation (TTS(v)) in fingertip on hand-arm vibration exposure period.</p><p><b>METHODS</b>Six healthy students were instructed to grip a vibrating or nonvibrating handle in the experimental room. The gripping force was 40 N. The vibratory sensation threshold at 125 Hz was measured before and after the exposure in the exposed middle fingertip. The exposure vibration was vertical and the 1/3 octave-band vibration with had a central frequency of 200 Hz and an intensity of 39.2 m/s(2). The exposure periods were 8, 15, 30, 60, 120, 240 and 600 s. TTS(v,t) was evaluated as the difference in vibratory sensation threshold between immediately before and t seconds after the exposure.</p><p><b>RESULTS</b>TTS(v) recovered exponentially as in several previous studies and its use enabled us to estimate the time constant and TTS(v,0). TTS(v,0) with vibration exposure was significantly larger than that without it. The regression analysis of the relationship between vibration exposure period (T) and TTS(v,0) (T) for each subject confirmed the good fit of the equation TTS(v,0)(T)=B(0)+B(1) (*)Log(10)(T), where B(0) and B(1) are the calculated constants (adjusted R(2)=0.56-0.87). The time constants did not show such a clear dose effect relationship of exposure period as TTS(v,0).</p><p><b>CONCLUSION</b>The dependency of TTS(v,0) on vibration exposure period was asymptotically proportional to the logarithm of gripping period. To more quantitatively confirm the relationship of the time constants for recovering time course of TTS(v), it may be necessary to improve the measurement method for TTS(v).</p>