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Brainstem auditory evoked responses were recorded in a neurosurgical intensive care unit in 38 patients who had all the clinical criteria for brain death. Of the brain-dead patients, 65.8% never showed a response. 3.42% showed a type I wave, which was unilateral in 26.3% and bilateral in the other 7.9%. Types II to VII waves were never seen. An increase in latency of type I waves (2.25 +/- 0.24 ms) was noted. The interest and the limits of this non invasive electrophysiologic technique for the diagnosis of brain death are discussed.  相似文献   

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Summary Thirty-three patients fulfilling the clinical criteria for brain death were tested by Brainstem Auditory Evoked Potentials (BAEP) and Radionuclide Cerebral Angiography and Brain Perfusion Studies. There was a significant correlation between the BAEP and radionuclide study outcomes. All patients with absence of BAEP showed no cerebral perfusion. These findings, added to the clinical findings, resulted in a final diagnosis of brain death in all patients. It is concluded that BAEP and Radionuclide Cerebral Perfusion studies are useful adjuncts for proving that brain death has really occurred.  相似文献   

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In 37 patients brainstem auditory evoked potentials were recorded within 48 hours from a mild head injury. About half of the patients had at least one abnormal neurophysiological parameter pointing to dysfunction of brainstem structure.  相似文献   

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We have used retrolabyrinthine vestibular neurectomy in 36 of 49 cases as the primary surgical procedure to relieve vertigo. Most of the patients (46 of 49) had Meniere's disease. Results indicate that 71% (35 of 49) of the patients had no vertigo after the operation, while 22% (11 of 49) had much improvement. Hearing was maintained within 20 dB of the preoperative level in 78% (38 of 49) of the patients. During surgery in the last 23 patients, direct nerve potentials were recorded from the middle ear promontory and the intracranial cochlear nerve. Brain stem auditory evoked responses were simultaneously recorded in the last 10 patients. It appears that the intraoperative direct cochlear nerve potentials can be used as a sensitive monitor of trauma to the cochlear nerve during and after vestibular neurectomy. If the latency of the eighth nerve action potential changes less than 0.3 msec and the waveform does not change after vestibular neurectomy, there is an excellent chance that hearing at 1 month after surgery will be within 15 dB of the level before surgery. The retrolabyrinthine vestibular neurectomy has replaced the middle fossa vestibular neurectomy and the endolymphatic subarachnoid shunt procedure in our clinic.  相似文献   

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利多卡因对脑干听觉诱发电位的影响   总被引:2,自引:1,他引:1  
目的 观察利多卡因对小脑幕下肿瘤患者脑干听觉诱发电位 (BAEPs)的影响。方法小脑幕下肿瘤病人 2 0例 ,随机分为A、B两组 ,每组 10例。A组为观察组 ,在术前以 0 33mg·kg-1·min-1的速度持续输注 2 %利多卡因 ,至总量达 10mg/kg止 ,并持续监测BAEP。B组为对照组 ,不用利多卡因。结果 A组从输注利多卡因后第 6min开始 ,Ⅰ、Ⅲ、Ⅴ波潜伏期及Ⅰ~Ⅲ、Ⅰ~Ⅴ波间潜伏期较注药前显著延长 ;且随着利多卡因输注剂量增加 ,各波潜伏期逐渐延长。其中Ⅰ、Ⅲ、Ⅴ波潜伏期及Ⅰ~Ⅲ、Ⅰ~Ⅴ波间潜伏期的延长值与利多卡因剂量呈线性相关。B组在全监测过程中BAEP无显著改变。结论 静脉注射一定剂量的利多卡因显著延长BAEP的潜伏期及波间潜伏期 ;在 0~ 10mg/kg剂量范围内 ,Ⅰ、Ⅲ、Ⅴ波潜伏期及Ⅰ~Ⅲ、Ⅰ~Ⅴ波间潜伏期的延长值与利多卡因的剂量呈线性相关  相似文献   

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Summary Bilateral recordings of brain stem auditory evoked responses were compared with the 40 Hz middle latency auditory evoked responses in 38 patients either brain dead or in coma grade IV. In 4 cases the 40 Hz auditory evoked potential was partly preserved, while the brain stem auditory evoked potential was not reproducible beyond wave II.Recording of the 40 Hz auditory evoked potential is found to be more sensitive in some rare instances.This study was supported in part by the Deutsche Forschungsgemeinschaft, grant Fi 390-1-857/88.  相似文献   

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Isolated fourth ventricle is an untoward but interesting complication caused by the shunt procedure, which has been recognized since the introduction of CT scanning. Auditory brain stem evoked potentials (BAEPs) were recorded in a patient with isolated fourth ventricle for assessment of brain stem function. Case 1. A 9-year-old boy. He had undergone repair of the lumbosacral meningocele at birth, followed by shunting procedures, including repeated shunt revision, for hydrocephalus which subsequently developed. CT scanning on admission revealed typical findings of isolated fourth ventricle, while neurological examination disclosed no abnormalities. BAEPs on admission revealed normal waves both in amplitude and latency. This patient has been doing well without further shunting procedures. Case 2. A 17-year-old male was admitted with complaints of headache, diplopia, nystagmus and ataxic gait. He had a history of operation for radical removal of cerebellar astrocytoma and lateral ventriculo-peritoneal shunt at 9 years of age. CT scanning on admission revealed a typical isolated fourth ventricle, and fourth ventricle-peritoneal shunt was performed. Postoperative serial BAEPs revealed gradual improvement of brain-stem function. Clinically he has been symptom-free thereafter except for slight nystagmus. Case 3. A 2-year-old female suffering from hydrocephalus developed after neonatal intraventricular hemorrhage and ventriculitis. After repeated revision of a lateral ventriculo-peritoneal shunt, she was admitted in semicoma with vomiting and opisthotonic posture. CT study revealed an isolated fourth ventricle and preoperative BAEPs showed marked abnormalities. Although fourth ventricle-peritoneal shunt was performed, no remarkable change in BAEPs was obtained, and neurological deficit of considerable degree persisted.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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Multimodally evoked potentials were registered in 85 patients who fulfilled the criteria for brain death. While samatosensory and visual evoked potentials have been found to be of limited value for the diagnosis of brain death, the stepwise abolition of brain stem auditory evoked potentials (BAEP) confirmed brain death in 26 out of 85 patients, i. e. 31%.Registration of the abolition of BAEP is concluded to be a safe and acceptable confirmatory test. It is, however, more feasible for institutions, in which BAEP are analysed routinely. In spite of all efforts sequential BAEP could not be used for the diagnosis of brain death in the majority of cases either because of absence of reproducible responses at the initial registration or because the patient was already apnoic at the time of the initial BAEP. Assuming that bilateral preservation of wave I has the same significance as the stepwise abolition of BAEP, since it also proves the integrity of the peripheral receptor, BAEP are relevant for the declaration of brain death in approximately 30% of patients.  相似文献   

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A series of 31 neurosurgical procedures in the posterior fossa monitored intraoperatively with ipsilateral brain stem acoustic evoked potentials (BAEPs) is analyzed for intraoperative potential changes. The evaluation of patients included pre- and postoperative BAEP recordings and pure tone audiometry. The series included 25 tumors, 4 neurovascular decompressions, 1 basilar artery aneurysm, and 1 arteriovenous malformation. Two intraoperative findings correlated significantly with a postoperative decrease in hearing: an amplitude reduction of more than 50% for Waves I to V and the loss of one of the waves, even if it was a wave that first appeared intraoperatively. We could attribute no significance to reversible or irreversible latency increases for all waves. The transient loss of one of the peaks followed by its reappearance was also insignificant with regard to postoperative hearing. A good prognostic sign was the intraoperative appearance of a peak undetectable on the preoperative recordings. These findings suggest that in intraoperative BAEP monitoring the observation of amplitude reduction is more important than that of latency increases. The surgeon should be informed when an amplitude reduction of more than 50% occurs before the peak is lost totally, as it is impossible to predict whether this peak will reappear intraoperatively.  相似文献   

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A monkey model of transtentorial brain herniation (TBH) was created to simulate the clinically encountered situation of a gradually expanding intracranial lesion. TBH was produced by extradural balloon inflation over a 4-hour period and documented by the appearance of the pupils as dilated or fixed at midposition. Intracranial pressure (ICP), brain stem auditory evoked potentials (BAEP), and short-latency somatosensory evoked potentials (SSEP) were recorded before, during, and after TBH. Statistical significance from baseline values to TBH was found for diminution of the BAEP amplitude, rise of the ICP, and diminution of the SSEP amplitude. An ICP rise to twice the baseline value and a 25% decrease in Wave V amplitude was found 1 hour before TBH. Changes in BAEP and SSEP took several minutes after deflation to return to baseline values. Analysis of Wave V of the BAEP was as sensitive as ICP in warning of TBH. Discussion centers upon previous animal studies of brain herniation and ICP elevation, and findings reported in humans deteriorating as a result of intracranial mass lesions. BAEP and SSEP monitoring may be used as noninvasive tests for brain stem compression in the setting of primate TBH, and in the future may be used to guide the effectiveness of therapy.  相似文献   

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The brain stem auditory evoked response (BAER) was monitored intraoperatively in 11 patients with tumors of the posterior fossa. A technique for the objective quantitative assessment of the BAER based on the variance of the phase angle between small group averages is described. The resulting component synchrony measure corroborated standard peak latency and amplitude changes of the BAER during operative manipulation. A discussion of the replication and use of the objective measure is presented.  相似文献   

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Symptomatic Arnold-Chiari malformation (Chiari II) is a recently described clinical entity, the natural history and surgical management of which remain controversial. The brain stem auditory evoked potentials (BAEPs) have been described as abnormal in 50 to 86% of children with myelomeningocele. We present the case of a full-term infant with myelomeningocele, shunted hydrocephalus, and Chiari II malformation who was surgically treated by decompression when she was 3 weeks old. BAEPs recorded immediately after decompression showed dramatic improvement over BAEPs recorded immediately before decompression, an improvement that could not be attributed to maturation of the central nervous system. It is postulated that in further large series the degree of abnormality in BAEPs may be of value in predicting the clinical course of these patients. The current status of BAEPs as they apply to the evaluation of posterior fossa anomalies is reviewed.  相似文献   

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We have encountered an example of the insensitivity of brain stem auditory evoked potentials (BAEPs) for monitoring the brain stem during a posterior fossa operation. The addition of somatosensory evoked potential recording to conventional BAEP protocols is readily accomplished and is likely to improve the sensitivity of intraoperative electrophysiological assessment of brain stem function.  相似文献   

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Complete cerebral ischemia lasting 20 and 30 min was produced in dog brains. Before and after complete ischemia early and middle latency auditory evoked potentials were recorded simultaneously. In all cases of complete ischemia for 30 min amplitudes of evoked potentials were diminished during the reperfusion period of 8 to 12 hours. In some cases evoked potentials reappeared only temporarily. After complete ischemia of 20 min duration, the amplitude of evoked potentials varied within a wide range. They could reach nearly normal values.  相似文献   

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SEP were recorded in 14 patients, who fulfilled the clinical and electroencephalographic criteria of brain death. The results are compared with the respective ones in healthy subjects. Beside the absence of cortical N 20 in each brain dead patient, reduction of amplitude or absence of near field negativity (N 13b) from upper neck regardless of the position of the reference electrode represents the predominant result. The near field potential from the lower neck (N 13a) was unaffected. The counterpart in the far field potential recorded from F z was amplitude reduction of P 13. These results suggest that the dissociation of N 13a and N 13b can confirm the diagnosis of brain death. Moreover these results support the view of two independent generators of N 13a and N 13b despite their identical amplitude and latency.  相似文献   

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对10例患者研究了脑干听觉诱发电位(BAEP)潜伏期与异氟醚麻醉浓度定性及定量关系。全麻诱导采用2.5%硫喷妥钠(3~5mg/kg),阿曲库铵(0.6mg/kg)。气管插管后麻醉维持采用1.15%、1.73.%、2.30%异氟醚及60%N2O,肌松维持用阿曲库铵。记录麻醉前、诱导后,1.15%、1.73%、2.30%及减至1.15%异氟醚时BAEP峰潜期(PL)和峰间潜伏期(IPL)值。结果表明,BAEP波VPL能稳定反映异氟醚麻醉浓度变化,具有等级性并呈正相关关系,BAEPPL、各波正常值似可作为判断异氟醚麻醉深度的参考标准。  相似文献   

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