Biomedical subjects

Li-ming Yu

Publications and source records attributed to Li-ming Yu.

4 recordsLinked to original sources

PubMed2006

[Preliminary study of intraoperative auditory monitoring techniques in acoustic neuroma surgery].

OBJECTIVE: To investigate the value of intraoperative auditory monitoring techniques in acoustic neuroma surgery. METHODS: Ten cases with acoustic neuroma were resected with retrosigmoid approach. Continuous hearing monitoring of auditory brainstem responses (ABR) and transtympanic electrocochleography (ECochG) was performed during operation. RESULTS: Before surgery, 3 patients had class A hearing, 4 had class B hearing, and 3 had class C hearing. With ABR monitoring, 5 patients had waves I , III and V, 5 had only waves I preoperation. After anesthesia,only 2 cases had waves I, III and V, 6 had wave I (Compound action potential, CAP N1 is equivalent to wave I of ABR) and 2 had no waves. The hearing was preserved in 2 cases, which had class A hearing post operation with tumor size <2 cm. With continuous hearing monitoring, the waves of I , III and V could be evoked in one case. In another case, the waves of I, III could be evoked after the tumor resection with the disappearance of wave V. The hearing was not preserved in 8 cases. The 6 out of 8 cases showed up CAP (waves I ) waveform. The CAP amplitudes decreased significantly in 4 cases and even dropped to zero while dissecting the tumor at the lateral end of the internal auditory canal (IAC) or clamping the internal auditory artery (IAA) during operation. After surgery, the CAP amplitudes were recovered to 50%-60% of normal level or normal. In one case, although the cochlear nerve was cut down, the CAP could still be recorded after the tumor resection. However, the CAP amplitudes was dropped to zero while pressurized and pulled cochlea nerve of brainstem lateral and the wave disappeared post-operation in another cases. The waves had not been recorded in two cases after anesthesia. One of them showed low amplitude of CAP wave when the tumor partially removed. The others had no wave all the time. CONCLUSIONS: In combination with ABR monitoring, ECochG proved to be a useful supplementary tool for hearing preservation in acoustic neurinoma surgery. Drilling of the IAC and tumor removal at the lateral end of the IAC were the most critical steps for achieving hearing preservation. The surgeon's experience are the most significant factors influencing the hearing outcome after removal of acoustic neuroma.

Adolescent↗

PubMed2004

[Characteristics of the response of vestibular evoked myogenic potentials to different stimulus modes].

OBJECTIVE: Vestibular evoked myogenic potential (VEMP) has been utilized in clinic to test the function of saccule. In the present study, 3 stimulus modes were applied to 21 normal adults and intended to draw in a clinical test protocol. METHODS: The normal latency and amplitude of VEMPs of 21 normal subjects were recorded and the ratio of bilateral amplitudes and asymmetry were calculated. RESULTS: The response to binaural clicks were similar to the response of the monaural clicks. The interindividual variation in amplitude were large, but the latency varied little. CONCLUSIONS: VEMPs is a stable myogenic potentials. Monaural and binaural clicks stimulus can be used in clinical practice. The latter is appropriate for normal hearing subjects. Amplitude measurement is probable to evaluate the asymmetry of bilateral saccular function and may reveal saccule lesion.

Acoustic Stimulation↗

PubMed2004

[Inferior vestibular nerve impairment in auditory neuropathy].

OBJECTIVE: To investigate if auditory neuropathy have inferior vestibular nerve (IVN) lesion and to explore the relation between AN and the IVN lesion by vestibular evoked myogenic potentials (VEMPs). METHODS: VEMPs were observed in 13 patients with auditory neuropathy. And the relation among the duration, hearing threshold of lower frequency and speech discrimination score with VEMPs were observed. RESULTS: Fifty-four percent patients in auditory neuropathy had abnormal VEMPs. They took the form of lower amplitude and no response. The statistical analysis showed that the abnormality of VEMPs had no correlation with lower frequency hearing loss, the duration and speech discrimination score. CONCLUSIONS: The IVN dysfunction may coexist with auditory neuropathy, having lesion in the IVN. However, there was no significant relation between the severity of AN and VEMPs, which meant that AN and inferior vestibular neuropathy had their independence to some extent.

Adolescent↗

PubMed2003

[Phanerogenetic retrocochlear low frequency hearing loss].

OBJECTIVE: To study the pathogenisis of retrocochlear low frequency hearing loss. METHODS: Clinical and audiologic findings [auditory brainstem response (ABR), evoked otoacoustic emission (EOAE), et al] of 29 cases with retrocochlear low frequency hearing loss were studied. RESULTS: The head injury, acoustic neuroma, peripheral neurophathy, hereditary hear loss, multiple sclerosis and brainstem disease can cause retrocochlear low frequency hearing loss. The typical clinical manifestations of retrocochlear low frequency hearing loss were normal EOAE which cannot be suppressed by contralateral white noise, but with abnormal ABR as well as with no acoustic reflex and -SP/AP > 0.44. CONCLUSIONS: The results suggest that phanerogenetic retrocochlear low frequency hearing loss should be a syndrome rather than a disease called "auditory neuropathy". The main lesions of the disease are brainstem, cochlear nuclei and auditory nerve.

Adolescent↗