Clinical features of neonatal seizures

Objectives: Identification of seizures in neonates is difficult. This study analyses the clinical features of seizures in a cohort of neonates.
Methodology: The clinical events of 41 neonates referred for investigation of suspected seizures were studied with prolonged video/electroencephalographic (EEG) telemetry.
Results: Sixteen neonates had no seizures recorded; 25 had confirmed seizures, 13 with clinical correlates. Each neonate with electroclinical seizures had paroxysms of abnormal movements in stereotyped patterns. These patterns were consistently found to have electrical correlates. Focal clonic movements were seen most frequently. Multiple clinical features characterized the seizure repertoire in six neonates. In five neonates the clinical features became less evident during monitoring and these seizures were difficult to recognize. This change was associated with anticonvulsant administration in three cases.
Conclusions: Electroclinical seizures are characterized by abnormal paroxysmal stereotyped behaviour, often with multiple clinical features. Recommendations for the management of abnormal neonatal events are proposed.     

Nucleus人工耳蜗电极阻抗测试的研究

目的探讨NucleusCI24M与NucleusCI24R．（CS）型人工耳蜗电极阻抗的区别。方法应用神经反应遥测技术（NRT）监测I6例NucleusCI24M与I0例NucleusCI24R（CS）型人工耳蜗电极的阻抗。结果所有电极阻抗值正常，两种类型的人工耳蜗电极阻抗差异存在显著性，并且人工耳蜗电极植入后，其阻抗会发生规律性变化，在术中测试电极阻抗数值存在从蜗底到蜗顶逐渐上升的现象。结论NucleusCI24M与NucleusCI24R（CS）的电极阻抗存在明显差异，电极植入后，其阻抗值随时间发生的规律性变化与机体生理活动有关。在相同条件下NucleusCI24R（CS）比NucleusCI24M更加节能有效。     

神经反应遥测技术在人工耳蜗术后调试中的应用

目的通过对小儿人工耳蜗植入者术后言语处理器调试中运用NRT（神经反应遥侧）技术效果的分析．探讨NRT在人工耳蜗术后调试中的应用价值。方法选取10例术后主观调试配合欠佳的儿童．用Cochlear公司NRT3．0编程软件进行ECAP波形检测并测定ECAP阈值，利用测试结果判断主观阈值（T-值）和最大舒适阈（C-值），并得出言语处理器映射图（Map）。术后6个月行声场听阈测听。结果86．2％的电极引出ECAP波形，开机调试时反应阈值较小，以后逐渐升高，3～4个月左右闽值逐渐趋于稳定，而且靠近蜗底的阈值比蜗尖高。声场平均听阈为30～40dBSPL。经过言语康复训练，获得良好的效果。结论NRT技术可为术后快速准确地调试言语处理器提供客观依据．     

Nucleus24型人工耳蜗使用者电诱发听神经复合动作电位的测定

目的 :探讨电诱发听神经复合动作电位 (ECAP)的特点及在人工耳蜗临床中的应用价值和意义。方法 :应用NRT(neuralresponsetelemetry)软件 ,通过体外言语处理器和耳蜗内的植入电极系统 ,采用单极模式电极刺激和近场记录方法 ,对 37例NucleusCI2 4M装置使用者进行ECAP的记录。对其中 12例使用者做了行为测试。结果 :87.6 %的使用者记录到ECAP波形。分析了有行为阈值的 12例测试者的ECAP阈值和行为阈值的关系 ,二者之间存在显著的相关性。结论 :ECAP的检出率高且波形稳定可靠 ,在临床人工耳蜗装置的调试中可作为对行为测试的补充 ;对于年幼儿童和首次开机的患者的调试尤其重要     

Repeated sensory contact with aggressive mice rapidly leads to an anticipatory increase in core body temperature and physical activity that precedes the onset of aversive responding

The present study investigated whether the 'psychological threat' induced by sensory contact with an aggressive conspecific would be a sufficient factor in inducing behavioural and physiological disturbances. Repeated sensory contact with an aggressive mouse (social threat) in a partitioned cage was compared with repeated exposure to a novel partitioned cage in male NMRI mice. We first examined parameters of stress responsiveness (body weight, plasma corticosterone levels, frequency of self-grooming and defecation). The temperature and physical activity responses to stress were also recorded during and after the 4 weeks of stress using radiotelemetry. Finally, cognitivo-emotional performance was assessed after acute stress and 2 and 4 weeks of stress by measuring decision making, sequential alternation performance and behaviour in the elevated T-maze. Social threat had a greater impact than novel cage exposure on most parameters of stress responsiveness, although mice did not habituate to either stressor. Social threat rapidly led to an anticipatory rise in core body temperature and physical activity before the scheduled stress sessions. Such anticipation developed within the first week and persisted for 9 days after ending the stress procedure. Some memory impairment in the sequential alternation test was found in stressed mice, independent of the stressor. After 4 weeks of stress, inhibitory avoidance in the elevated T-maze was enhanced in socially stressed mice and reduced in novel cage mice. The sustained anticipation of stress in the social threat group preceded aversive responding. It remains to be established whether anticipation contributes to the development of aversive responses.     

Comparison of telemetric and tail-cuff blood pressure monitoring in adrenocorticotrophic hormone-treated rats

1. The aim of the present study was to validate a telemetric blood pressure (BP) monitoring system against tail-cuff blood pressure in both adrenocorticotrophic hormone (ACTH)- and sham-treated rats. In the statistical analyses, we first tested whether there was a detectable effect on systolic blood pressure (SBP) of 10 days treatment with ACTH compared with saline. Second, we compared results of telemetered and tail-cuff measurements and, third, we developed a novel method for estimating the relative power of the two techniques. 2. Twenty-three male Sprague-Dawley rats were randomly divided into two groups: (i) ACTH (100 microg/kg per day, s.c; n = 12) treated; or (ii) sham treated (0.9% saline, s.c; n = 11). Systolic BP was measured by the telemetric system (sampled for 10 s every 2 min) continuously for 4 h (n = 16) or for 30 min (n = 23) and also by the indirect tail-cuff method daily (n = 23). Data were compared within and between groups; ordinary least products (OLP) regression analysis was then performed to test for bias between the two methods. Sample size/power estimations were also performed. 3. Adrenocorticotrophic hormone treatment raised telemetered SBP by 11 mmHg (P < 0.001) compared with 14 mmHg (P < 0.001) using the tail-cuff method. There was no fixed or proportional bias between the two methods of measurement, as shown by regression analysis. Power calculations indicate that a minimum sample size of six gives a power of telemetered to tail-cuff of 0.84/0.86 = 0.98. The power of 4 h versus 30 min BP measurements was 0.99/0.82 = 1.2. 4. Telemetry gave very similar results to the tail-cuff method. Telemetry allows for a longer period of measurement, giving greater power to the study so that fewer animals are needed.     

Validation du Sport Tester PE 3000 en fonction de l'enregistrement Holter

This study aims to validate the measurements of heart frequency (FC) as obtained both with the ‘Sport Tester PE 3000’ and the new ‘Long Range Telemetry PE 3000’ with respect to the same measurements recorded with the ‘Holter’ ECG as reference values. Twenty subjects were submitted to a variable 50 min work-out. The heart frequency was measured every 15 sec simultaneously with the three instruments. The telemetric device could be applied to only ten subjects. The results show that the choice of apparatus had no significant influence on the heart rate registration, with high correlations and unsignificant difference between the three types of measurement.In conclusion, the Sport Tester PE 3000 and its long range telemetry system are valid alternatives on field and for research purposes for the fragile and unwieldy Holter apparatus.     

The Rotterdam teletransducer: State of the device

Summary The developments of a telemetric device for monitoring intracranial pressure, the Rotterdam Teletransducer, are described. The major problem in telemetric pressure sensing devices consists of diffusion of water into the transducer, resulting in unpredictable zero drift. Therefore, special attention was paid to bonding techniques for sealing the transducer.The results of improved epoxy sealing, active metal brazing and glass bonding are described. In vitro tests showed transducers sealed with epoxy resin to be stable for two months. Using the more complicated tchniques of glass bonding and active metal brazing, hermetic seals could be achieved with stable transducers for over one year. In vivo functioning of the Rotterdam Teletransducer was tested in acute and chronic animal experiments. The in vivo results corresponded to those obtained in the in vitro experiments. Regression analysis between epidural and ventricular fluid pressure showed a one to one ratio.Results of clinical application of the device in 22 patients are described. Accurate depth setting of the transducer on the dura, according to the pressure depth curve, was shown to be essential.The device has also been used with success for non-invasive fontanelle pressure measurements in infants. The depth positioning of the transducer on the fontanelle according to a pressure depth curve is described.This paper has been awarded by the 1985 Casey Holter Memorial Prize by the Society for Research in Hydrocephalus and Spina Bifida.     

神经反应遥测技术在低龄幼儿人工耳蜗植入术后调试中的指导作用

目的:探讨神经反应遥测技术(NRT)在低龄幼儿人工耳蜗植入术后调试中的指导作用。方法:记录41例低龄幼儿开机时、3个月、半年的NRT阈值以及开机半年的行为反应C、T值。结果:对246个电极进行不同时期NRT测试,波形检出情况一致,205个(83.33％)引出NRT波形。而在行为反应测听中,246个(100％)电极均有明确的T、C值;NRT阈值与T、C值之间有相关性,NRT阈值介于T、C值之间,靠近C值;同一患者不同编号电极之间无论NRT阈值还是T、C值均变化不大,经t检验,无显著性差异(P>0.05);不同患者相同编号电极各值差距较大。结论:应用NRT阈值可以估算行为反应T、C值,为低龄幼儿开机初期的凋试提供帮助。     

Inappropriate Discharges by the Implantable Cardioverter Defibrillator During Postoperative Testing: Implications for Intraoperative Assessment

Inappropriate shocks were delivered to a patient while in sinus rhythm by an implantable cardioverter defibrillator (ICD) during routine prehospital discharge testing. This was induced by the standard programmer when the "read" telemetry sequence was initiated. The ICD was removed and found to suffer from electrical artifact that was sensed as ventricular tachycardia during telemetry. To avoid inadvertent telemetry-induced shocks during routine testing, all ICDs should be interrogated, using a standard programmer, intraoperatively, with the unit in "defibrillation on" mode.