Local response caused by implant after cochlear implantation / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To approach the incidence rate, symptoms, etiologies, correlating reasons, consequences and treatments of local responses caused by implant after cochlear implantation and to provide reference for the future works.</p><p><b>METHODS</b>From 1995 to 2007 there were 997 cases adopted cochlear implantation in Peding Union Medical College Hospital. Ten cases experienced local responses were analyzed retrospectively.</p><p><b>RESULTS</b>The incidence of local response was 1.003%. There were 6 males and 4 females. The ages were between 13 months to 8 years old. The average age was 34 months. The devices mainly were made by Cochlear and Med-EL companies. The mainly symptoms and signs were local swellings, complaint of pruritus after ear, decrease of sound legibility and so on. Onset frequencies of this disease was 1 to 8 times. The bacterium cultured of displacing liquids was negative. But the IgE was detected in 2 cases. Results showed the patients were midrange status of hypersensitivity. Positive conservative treatments must be done including antibiotics, antihistamines, necessarily using immunotherapy.</p><p><b>CONCLUSIONS</b>Besides local infection of bacteria, the allergy caused by silicone of implant coupled be a reason. Although the diagnose of this disease was difficult, but the screening of source of hypersensitivity was necessary before operation. It was recurrent attacks and maybe liable by kindred patients. Onset age was more below 4 years old. The patch test should be done again when the symptoms were occurrence after operation. If severe secondary infection was occurred and the states could not be well controlled the devices in the body must be explanted immediately. When the conditions were stable reimplantation could be experienced by non-sensibilisinogen devices.</p>

Auditory pre-attentive processing of Chinese tones / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Chinese tones are considered important in Chinese discrimination. However, the relevant reports on auditory central mechanisms concerning Chinese tones are limited. In this study, mismatch negativity (MMN), one of the event related potentials (ERP), was used to investigate pre-attentive processing of Chinese tones, and the differences between the function of oddball MMN and that of control MMN are discussed.</p><p><b>METHODS</b>Ten subjects (six men and four women) with normal hearing participated in the study. A sequence was presented to these subjects through a loudspeaker, the sequence included four blocks, a control block and three oddball blocks. The control block was made up of five components (one pure tone and four Chinese tones) with equiprobability. The oddball blocks were made up of two components, one was a standard stimulus (tone 1) and the other was a deviant stimulus (tone 2 or tone 3 or tone 4). Electroencephalogram (EEG) data were recorded when the sequence was presented and MMNs were obtained from the analysis of the EEG data.</p><p><b>RESULTS</b>Two kinds of MMNs were obtained, oddball MMN and control MMN. Oddball MMN was obtained by subtracting the ERP elicited by standard stimulation (tone 1) from that elicited by deviant stimulation (tone 2 or tone 3 or tone 4) in the oddball block; control MMN was obtained by subtracting the ERP elicited by the tone in control block, which was the same tone as the deviant stimulation in the oddball block, from the ERP elicited by deviant stimulation (tone 2 or tone 3 or tone 4) in the oddball block. There were two negative waves in oddball MMN, one appeared around 150 ms (oddball MMN 1), the other around 300 ms (oddball MMN 2). Only one negative wave appeared around 300 ms in control MMN, which was corresponding to the oddball MMN 2. We performed the statistical analyses in each paradigm for latencies and amplitudes for oddball MMN 2 in discriminating the three Chinese tones and reported no significant differences. But the latencies and amplitudes for control MMN in discriminating the three tones all were significantly different.</p><p><b>CONCLUSIONS</b>There are evident waveforms for oddball and control MMN obtained in normal hearing persons, indicating that the change of Chinese tones could be detected in the pre-attentive stage. Because control MMN can eliminate reflects for physical characteristics of sound, it is the genuine memory-based pre-attentive processing. Since control MMN can reflect the differences of Chinese tones processing better than oddball MMN, it is more sensitive in evaluating pre-attentive processing in Chinese tones discrimination.</p>