The blink reflex in migraine

The blink reflex is an objective and useful method to study the trigeminal system. It was recorded in 43 migraine patients and the findings compared with those of 31 healthy controls. The latencies of the R1 component were in the normal range in both groups. The R2 latencies ranged between 30 and 32 ms in the control group. In contrast, more than half of the patients with migraine had R2 latencies between 32 and 35 ms in the migraine group. Some migraine patients had latencies above 35 ms. The R2 latency was statistically significantly different between controls and migraineurs (p < 0.0001). Our findings indicate that trigeminal afferents and/or polysynaptic pathway in brainstem may be altered in migraine.     

Sympathetic skin responses from frontal region in migraine headache: a pilot study

Frontal sympathetic skin responses (F-SSRs) were recorded to investigate sympathetic nervous system activity in migraine headache (MH). Thirty-five patients with unilateral MH and 10 healthy volunteers were studied by evoking bilateral F-SSRs with electrical stimulation of the median nerve in attack, post-attack and interictal periods. The mean latencies were longer and the maximum amplitudes were smaller on the symptomatic side compared with the asymptomatic side ( P  < 0.05 for both amplitude and latency) in attack and in interictal periods. In five patients, F-SSRs were absent bilaterally, in four patients the responses were absent only on the symptomatic side during the attack period. In the post-attack period, F-SSRs on the symptomatic side had higher amplitudes and shorter latencies compared with the asymptomatic side ( P  < 0.01 for both amplitude and latency). There is an asymmetric sympathetic hypofunction on the symptomatic side in attack and interictal periods, whereas there is a hyperfunction in the post-attack period.     

Cranial magnetic resonance imaging findings in patients with migraine

OBJECTIVE: To investigate the frequency of cranial magnetic resonance imaging abnormalities in patients with migraine and their relationship to type, duration, and frequency of migraine attacks. METHODS: Forty-five patients (43 women, 2 men) with migraine whose ages ranged between 19 and 53 years (mean, 40.91 [SD, 7.69]) were evaluated. Of the 45 patients, 20 had migraine with aura and 25 had migraine without aura, according to the diagnostic criteria of the International Headache Society. RESULTS: In 13 (28.8%) of 45 patients, white matter foci were present on magnetic resonance imaging. Eight of these patients (61.5%) had migraine with aura, and 5 patients (38.4%) had migraine without aura. The presence of white matter foci was significantly higher in the patients with aura (8 [40%] of 20) than in those without aura (5 [20%] of 25). It was found that as the frequency of attacks per month increased, the number of patients with white matter foci also increased. Although the mean duration of migraine was longer in patients with white matter foci (149.5 months [SD, 87.9]) than in those without white matter foci (134.1 months [SD, 88.3]), there was no significant difference (P >.05). CONCLUSION: Although there are no specific magnetic resonance imaging findings peculiar to migraine, detection of white matter foci should be taken into consideration in patients with migraine (especially migraine with aura). Frequency of attacks is an important indicator of existence of white matter foci.     

Passive paradigm single-tone elicited ERPs in tension-type headaches and migraine

The active 'oddball' event-related potential (ERP) P3 is elongated or reduced in migraine and tension-type headaches, indicating a deficit of active attention in these primary headaches. It is then reasonable to study the passive attention function in these headaches through the technology of passive paradigm single-tone elicited ERPs. We invited 32 patients suffering from chronic tension-type headache (CTTH), 17 from frequent episodic tension-type headache (FETH) and 32 from interictal migraine without aura, as well as 28 healthy subjects to undergo passive paradigm single-tone ERPs. There were no statistically significant differences when the mean latencies and amplitudes of N1, P2, N2 or the mean latencies of P3 of the four groups were considered. In contrast, the P3 amplitudes were significantly reduced in the patient groups when compared with healthy controls. However, no further significant difference was found between patient groups when considering P3 amplitude. Our study demonstrated a deficit of passive attention in CTTH, FETH and migraine, but could not separate these headache types in this regard. The reduced P3 in patients might be due to the head pain experienced.     

Visual, long-latency auditory and brainstem auditory evoked potentials in migraine: relation to pattern size, stimulus intensity, sound and light discomfort thresholds and pre-attack state

We aimed to estimate primary sensory evoked potential (EP) amplitude, amplitude-intensity functions and habituation in migraine patients compared with healthy control subjects and to investigate the possible relation to check size, sound and light discomfort thresholds, and the time to the next attack. Amplitudes of cortical visual evoked potentials (VEP, check size 8' and 33'), cortical long latency auditory evoked potential (AEP NIP1; 40, 55 and 70 dB SL tones) and brainstem auditory evoked potential (BAEP wave IV-V; 40, 55 and 65 dB SL clicks) were recorded and analysed in a blind and balanced design. The difference between the response to the first and the second half of the stimulus sequence was used as a measure of habituation. Twenty-one migraine patients (16 women and five men, mean age 39.3 years, six with aura, 15 without aura) and 22 sex- and age-matched healthy control subjects were studied (18 women and four men, mean age 39.5 years). Low sound discomfort threshold correlated significantly with low levels of BAEP wave IV-V amplitude habituation (r = -0.30, P = 0.05). VEP an AEP amplitudes, habituation, and amplitude-intensity function (ASF) slopes did not differ between groups when ANOVA main factors were considered. Control group VEP habituation was found for small check stimuli (P = 0.04), while potentiation was observed for medium sized checks (P = 0.02). The eight migraine patients who experienced headache within 24 h after the test tended to have increased BAEP wave IV-V ASF slopes (P = 0.08). This subgroup did also have a significant VEP habituation to small checks (P = 0.04). No correlation was found between different modalities. These results suggest that: (i) VEP habituation/potentiation state and brainstem activatio state may depend on the attack-interval cycle in migraine; (ii) VEP habituation/ potentiation may depend on spatial stimulus frequency; (iii) phonophobia (and possibly photophobia) may depend more on subcortical (brainstem) function than on cortical mechanisms; (iv) low cortical preactivation in migraine could not be confirmed; (v) EP habituation and ASF analysis may reflect sensory modality-specific, not generalized, central nervous system states in migraine and healthy control subjects.     

偏头痛患者认知量表和事件相关电位的研究

目的:研究偏头痛患者认知量表、事件相关电位(ERP)P3的改变及其相关性,探讨偏头痛对认知功能障碍的影响。方法:确诊为偏头痛的患者23例纳入偏头痛组,并根据发作前有无先兆分为无先兆偏头痛亚组16例及有先兆偏头痛亚组7例;纳入年龄、性别、教育水平相匹配的健康志愿者15例为对照组。均参与情绪量表、认知量表测评和ERP检查。采用"Oddball"经典范式为刺激任务,同步记录脑电信号。分别比较偏头痛患者与对照组认知量表测评得分,ERP P3成分潜伏期、波幅的变化及相关性分析。结果:(1)偏头痛组焦虑自评量表(SAS)得分较对照组高(P0.05),2组抑郁自评量表(SDS)得分差异无统计学意义。(2)偏头痛组的蒙特利尔认知评估量表(MOCA)量表、Rey-复杂图形测验--延迟回忆得分较对照组降低(P0.05)。(3)偏头痛患者Fz、Cz、Pz部位的P3潜伏期均较对照组显著延长(P0.05),波幅差异无统计学意义。同组内不同部位的P3潜伏期、波幅差异无统计学意义(P0.05)。有先兆偏头痛亚组与无先兆偏头痛亚组的P3波幅和潜伏期差异无统计学意义(P0.05)。(4)Rey-复杂图形测验-延迟回忆与P3潜伏期呈负相关,其相关系数为-0.519(F=8.853,P=0.007)。余量表与ERP无显著相关性(P0.05)。结论:偏头痛患者总体认知功能和视空间记忆能力较健康人下降,对信息加工处理的速度减慢。偏头痛患者有轻度认知功能障碍。     

Influence of disease duration on visual evoked potentials in migraineurs

OBJECTIVE: To determine the possible influence of the duration of migraine on pattern-reversal visual evoked potentials. METHODS: An investigation was conducted in 49 patients with migraine without aura according to the International Headache Society criteria. Twenty-two of these patients had had migraine for 2 years or less (group 1), and the other 27 patients had had the disease for 10 years or more (group 2). The control group consisted of 17 healthy subjects. RESULTS: Comparison of the mean P100 latency and amplitude showed no significant difference among the groups. There was, however, a good negative correlation between age and latency (r = -0.59, P =.003) in group 1, but no such correlation was observed for group 2 or the control group. CONCLUSIONS: It was concluded that the duration of migraine has no influence on pattern-reversal visual evoked potentials and that the pathogenesis of early- and late-onset migraine may be different.     

Abnormalities of Na/K ATPase in migraine with aura

It has been previously shown from our laboratory that abnormal functioning of Na/K ATPase can cause spreading depression, the likely mechanism of migraine aura. We used lymphocytes to investigate whether or not membrane Na/K ATPase is altered in migraine with aura patients. Lymphocytes were prepared from such patients, aged 20-45 years, and from age-matched healthy volunteers (controls). The binding of 3H- ouabain was studied using increasing concentrations (0.5-25 nm) of this radioligand, specific for Na/K-ATPase. We studied 19 migraine with aura patients and 22 healthy volunteers, matched for age and sex. B(max) (fmol/mg protein) and K(D) (nM) were not different between patients and controls. However, their ratio (B(max)/K(D)) was higher in patients than in controls. B(max) was (mean +/- SD) 270 +/- 110 fmol/mg protein in controls, and 360 +/- 230 in migraine with aura patients (P = 0.10, t-test). K(D) was (mean +/- SD) 2.8 +/- 1.5 nm in controls, and 2.9 +/- 3.2 nm in migraine with aura patients (P = 0.88, t-test). B(max)/K(D) was (mean +/- SD) 120 +/- 78 in controls, and 210 +/- 190 in migraine patients (P = 0.046, t-test). Moreover, no control patient had a B(max)/K(D) ratio greater than 398, while three migraine patients had ratios of 417, 572 and 722, respectively. Ouabain binding is affected by Na/K ATPase structure (K(D)) and expression (B(max)). While these parameters were not altered in migraine with aura patients, the difference in their ratio suggests an imbalance between the enzyme's ouabain affinity and its expression, with higher-affinity subtypes being more expressed than normal. Moreover, single patients had values quite different from the control population. Our data suggest that (i) ouabain binding to lymphocyte membranes may be a useful tool in the diagnosis of migraine with aura and (ii) Na/K ATPase abnormalities may be involved in migraine aura.     

Effect of interelectrode distance on sural nerve action potential parameters

OBJECTIVE: To assess differences in amplitude, latency, and duration, using a 3-cm vs. 4-cm distance between the active and reference electrodes when performing sural nerve conduction studies (NCS). Current normative data in lower-limb studies are generally based on 3-cm interelectrode differences, although 4-cm differences have been reported to be optimal in the upper limb. DESIGN: Prospective study comparing the onset latency, peak latency, duration, and amplitude for the sural sensory nerve action potential (SNAP) recording at two interelectrode distances in adult volunteers. RESULTS: Forty-three sural nerves were studied in 22 normal subjects. Peak latencies recorded with a 4-cm interelectrode distance were significantly longer than those recorded with a 3-cm distance (mean difference = 0.06 msecs [SD = 0.09, P = 0.0073]). Duration was significantly longer (mean difference = 0.03 msecs [SD = 0.07, P = 0.0270]), conduction velocities were significantly slower (mean difference = -0.7 msecs [SD 1.0, P = 0.0012]), and onset latency and amplitude were not found to differ significantly. Average differences in peak latencies, duration, velocity, onset latency, and amplitude were not correlated with gender, age, or BMI. CONCLUSIONS: In contrast to studies of upper-limb sensory NCS, sural SNAP parameters obtained with 3- and 4-cm interelectrode distances did not differ for onset latencies and amplitude. Peak latencies, duration, and conduction velocity differences, though statistically significant, were of insufficient magnitude to be clinically meaningful. By using a 4-cm instead of a 3-cm interelectrode difference for sural nerve studies, the small prolongation of 0.06 msecs in peak latency and tiny increment of 0.27 muV observed in our investigation is unlikely to influence the electrodiagnostician's interpretation of the study.     

Quantification of T wave shape changes following exercise

T wave shape is increasingly used to provide insights into cardiac repolarization and, although shape is known to change as heart rate changes, there are no published quantitative clinical data. The aim of this study was to quantify these changes. Heart rate (HR), T wave amplitude, and two measures of T wave symmetry (SRarea--ratio of areas about the peak, SRtime--ratio of centrality of peak), were quantified over a period of 360 seconds following exercise in 20 healthy human subjects. As HR decreased, in all subjects the T wave became more asymmetrical (SRarea 20/20, SRtime 20/20, P < 0.0001). Resting reference HR and symmetry ratios were (mean +/- SD), HR 63 +/- 10 beat/min, SRarea 1.68 +/- 0.25, and SRtime 2.13 +/- 0.39. Fifty seconds postexercise, HR was significantly higher than reference at 92 +/- 11 beat/min (P < 0.0001), and symmetry ratios were significantly less at SRarea 1.04 +/- 0.15, SRtime 1.24 +/- 0.36 (P < 0.0001). Significant differences in HR and both symmetry ratios remained at 300 seconds postexercise. Amplitude increases had returned to their reference values at 300 seconds. T wave shape was significantly more symmetrical at higher HRs. These findings confirm qualitative reports of shape changes.     

正常人标准胸导联和Mason-Likar胸导联心电图波段定量比较

目的：对我国正常人群标准12导联（标准导联）和Mason-Likar导联系统所记录胸导联心电图的波段进行定量比较。方法：选择84例冠状动脉造影和心脏超声检杏结果均正常者作为研究对象，其均接受标准导联加Mason-Likar导联心电网记录检查，观察2种导联系统胸导联心电图中以下测定值的相关性及差异，包括R波振幅、QRS波振幅、ST段值[J点（ST on）、J点后0．08s（ST80 ms）和终点（ST end）]、ST段斜率及T波振幅。结果：标准导联与Mason-Likar导联系统所记录的胸导联心电图存在良好相关性，但也存在统计学差异（P〈0．001）与标准胸导联相比，Mason-Likar胸导联心电网差异包括部分导联QRS波振幅明显降低、ST段显著下移伴V1～V0导联T波振幅下降，V1导联中各波段降低均较显著（P均〈0．001）；Mason-Likar各胸导联中ST段的降低幅度均超过同一导联QRS波和T波的幅度改变,以V6导联变化最显著。平均体重指数（BMI）与V1、V3导联QRS波振幅的改变呈负相关：V1、V2导联ST80ms与T波振幅、QRS波振幅的改变呈正相关。结论：标准导联与Mason-Likar导联系统所记录心电图波段有一定差异。     

Interictal potentiation of passive "oddball" auditory event-related potentials in migraine

We have studied habituation of the P3a component of the passive "oddball" auditory event-related potential which reflects automatic processing of a "novel" stimulus in 24 patients suffering from migraine without aura and in 21 healthy volunteers. Three blocks of responses to 160 standard and to 40 novel tones were sequentially averaged at Cz and analyzed for latencies and peak-to-peak amplitudes. Latencies of components N1 and P2 elicited by standard tones and of components N1, P2, N2, and P3a elicited by novel tones were not significantly different between sequential blocks or between subject groups, nor were mean N1-P2 amplitudes. The N2-P3a amplitude tended to be lower in migraine, but not significantly so. The most striking result in migraineurs was a significant potentiation of N2-P3a in successive blocks, contrasting with an habituation in controls. Our previous evoked- and event-related potential studies and the present one suggest that deficient habituation, or even potentiation, represents interictally a fundamental dysfunction of cortical information processing in migraine, which might increase energy demands and play a role in etiopathogenesis.     

Fetal middle cerebral artery peak systolic velocity in the investigation of non-immune hydrops.

OBJECTIVE: In some cases of non-immune hydrops there is congenital or acquired fetal anemia. The aim of this study was to investigate the potential value of fetal middle cerebral artery peak systolic velocity (MCA-PSV) in the assessment and management of non-immune hydrops due to anemia. METHODS: Fetal MCA-PSV and fetal hemoglobin concentration, in blood obtained by cordocentesis, were measured in 16 singleton pregnancies referred to our unit for further investigations because of a diagnosis of non-immune hydrops fetalis. In all cases a detailed ultrasound examination demonstrated moderate or severe ascites, with or without skin edema, and pericardial or pleural effusions. Furthermore, there were no obvious malformations to account for the hydrops. In each fetus the measured MCA-PSV and hemoglobin concentration were expressed as delta values (the difference in SD from the normal mean for gestation). Regression analysis was used to determine the significance of the association between delta MCA-PSV and delta fetal hemoglobin concentration. In addition, we searched our database to identify the sonographic features and hemoglobin concentration of fetuses with congenital infection. RESULTS: In the 16 cases of non-immune hydrops there were seven with parvovirus B19 infection, one each of alpha-thalassemia and primary cardiomyopathy and seven with no obvious explanation for the hydrops. There was a significant association between delta MCA-PSV and delta hemoglobin concentration (delta hemoglobin = (delta MCA-PSV + 0.1437)/-0.4154; R(2) = 0.7202; P < 0.0001). In 10 of the cases the fetal hemoglobin concentration was more than 4 SD below the normal mean for gestation and in all these cases the MCA-PSV was more than 2 SD above the normal mean for gestation. Our computer search identified an additional nine fetuses with parvovirus B19 infection and in all cases the predominant sonographic finding was ascites and the hemoglobin concentration was more than 4 SD below the normal mean. In contrast, only 3/14 fetuses with cytomegalovirus, toxoplasmosis, coxsackie B or Treponema infection had ascites and only 2/14 had a hemoglobin deficit of 4-6 SD. CONCLUSION: In the management of non-immune hydrops, measurement of fetal MCA-PSV can help identify the subgroup with fetal anemia.     

Visual evoked potentials in diabetic patients

Visual evoked potentials (VEPs) were assessed in 50 adult type I (insulin-dependent) and 19 type II (noninsulin-dependent) diabetes mellitus patients and in 54 controls. P100 wave latency was significantly longer in diabetic patients (P less than .001). Twenty-eight percent of diabetic patients had P100 wave latencies above the normal range. There was no correlation between P100 latency and type or duration of diabetes mellitus, quality of metabolic control, or presence of degenerative complications. The significance of VEP abnormalities in diabetes mellitus remains speculative.     

Determining Optimal Atrial Sensitivity Settings for Single Lead VDD Pacing: The Importance of the P Wave Histogram

In order to provide atrioventricular synchrony, VDD pacing systems require reliable atrial sensing. Variations in atrial signals with exercise and daily activities may lead to undersensing, with loss of physiological pacing. The aim of this study was to determine, for a single lead VDD pacing system, the maximal variation in atrial signals in order to facilitate optimal programming of atrial sensitivity. Fifteen patients underwent implantation of a Vitatron Saphir VDD pacemaker with a Vitatron Brilliant electrode. At a mean (± SD) follow-up of 67.3 ± 38.8 days, resting P wave amplitude was compared with the P wave amplitude histogram obtained from the pacemaker, which recorded atrial signals over the preceding 30 days. Resting P wave amplitude was also compared with P wave amplitudes during variations in posture, respiration, and during exercise. P wave amplitude showed great variation with changes in posture and respiration, but there was no consistent increase or reduction. During exercise, the mean P wave amplitude fell hy 36.6%± 31.3% compared with the resting value (P < 0.05). During daily activities, 22.6% of P wave amplitudes recorded on the P wave histogram were < 0.5 mV. The smallest P wave amplitudes were detected by the P wave histogram in 11 (79%) of 14 patients. These data suggest that atrial sensitivity may need to be programmed higher than that indicated by single readings or exercise. The P wave amplitude histogram is the most reliable indicator of the smallest atrial signal and should be used to opthnize atrial sensitivity settings.     

Influence of colors on habituation of visual evoked potentials in patients with migraine with aura and in healthy volunteers

OBJECTIVE: To investigate whether colored glasses influence the habituation of visual evoked potentials. BACKGROUND: We have previously shown that during pattern-reversal stimulations lasting 2 minutes the amplitude of the visual evoked potential increases in migraine with and without aura between attacks, whereas it decreases in healthy volunteers. Red light was found to increase visually evoked EEG fast activity only in children with migraine with aura. Wearing rose-tinted glasses for 4 months decreased attack frequency in parallel with a reduction of the visually evoked EEG fast activity. METHODS: We compared the change in amplitude of the visual evoked potential using five different tinted glasses in 12 patients with migraine with aura and in 10 healthy volunteers. During continuous stimulation at 3.1 Hz, five blocks of 50 responses were sequentially averaged using red, yellow, green, blue, and grey glasses and without glasses in a random order and analyzed in terms of latencies and N1-P1 amplitudes. Amplitude changes were calculated for each block by comparison with the first block in every condition and analyzed statistically using Zerbe's method. RESULTS: In healthy volunteers, the visual evoked potential amplitude increased with red glasses compared to without glasses (P = .05) or with green glasses (P = .03). In patients with migraine with aura, no significant difference was detected using colored glasses. Our findings in healthy volunteers are in line with earlier reports of increased excitability of the human visual cortex when exposed to red light. The lack of such a pattern in patients with migraine with aura suggests that the visual cortex is interictally hypoexcitable rather than hyperexcitable, which is consistent with studies of transcranial magnetic stimulation.     

Effects of pan- and subtype-selective N-methyl-D-aspartate receptor antagonists on cortical spreading depression in the rat: therapeutic potential for migraine

Spreading depression (SD) has long been associated with the underlying pathophysiology of migraine. Evidence that the N-methyl-D-aspartate (NMDA) glutamate receptor (NMDA-R) is implicated in the generation and propagation of SD has itself been available for more than 15 years. However, to date, there are no reports of NMDA-R antagonists being developed for migraine therapy. In this study, an uncompetitive, pan-NMDA-R blocker, memantine, approved for clinical use, and two antagonists with selectivity for NMDA-R containing the NR2B subunit, (1S,2S)-1-(4-hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)-1-propanol (CP-101,606) and (+/-)-(R*,S*)-alpha-(4-hydroxyphenyl)-beta-methyl-4-(phenylmethyl)-1-piperidine propanol (Ro 25-6981), were investigated to assess their protective effects against SD in the rat. Under isoflurane anesthesia, d.c. potential and the related cortical blood flow and partial pressure of O2 (pO2) were recorded simultaneously at separate cortical sites. Drugs (1, 3, and 10 mg/kg i.p.) were given 1 h or 30 min before KCl application to the brain surface. Core temperature and arterial pCO2,pO2, and pH measurements confirmed physiological stability. KCl induced 7.7+/-1.8 (mean+/-S.D.) SD events with d.c. amplitude of 14.9+/-2.8 mV. Memantine and CP-101,606 dose-dependently decreased SD event number (to 2.0+/-1.8 and 2.3+/-2.9, respectively) and SD amplitude at doses relevant for therapeutic use. Ro 25-6981 also decreased SD events significantly, but less effectively (to 4.5+/-1.6), without affecting amplitude. These results indicate that NR2B-containing NMDA receptors are key mediators of SD, and as such, memantine- and NR2B-selective antagonists may be useful new therapeutic agents for the treatment of migraine and other SD-related disorders (e.g., stroke and brain injury). Whether chronic, rather than acute, treatment may improve their efficacy remains to be determined.     

Assessments of chronodispersion and tacheodispersion of F waves in patients with spinal cord injury

OBJECTIVE: To evaluate the chronodispersion and tacheodispersion of F waves in patients with spinal cord injury and to determine whether these parameters are more sensitive than those of standard F waves. DESIGN: F chronodispersion and F tacheodispersion as well as F wave latencies, amplitude, and persistence were measured in tibial nerves of 23 male patients with different scales of spinal cord injury and 23 normal subjects. Spasticity was measured and correlated with F chronodispersion in spinal cord injury patients. RESULTS: F chronodispersion of 6.4 +/- 1.9 msec (mean +/- SD) obtained in spinal cord injury patients was found to be significantly greater than the results of 3.9 +/- 1.6 msec in normal controls (P < 0.05). F chronodispersion was greater in spinal cord injury patients with complete cord lesion. A positive correlation was found between F chronodispersion and Ashworth Scores in spinal cord injury patients. There were no significant differences in minimal latency, amplitude, persistence of F waves, and F tacheodispersion between spinal cord injury patients and normal subjects. CONCLUSIONS: Measurement of F chronodispersion may provide a useful and sensitive electrophysiologic assessment in evaluation of spinal cord injury and serve as an evident tool for differentiating pathologic from normal state motoneuron excitability in spinal cord lesion.     

糖尿病患者诱发电位的反应与临床参量的关系

目的了解2型糖尿病(DM)患者的视觉诱发电位(VEP),脑干听觉诱发电位(BAEP)、体感诱发电位(SEP)、事件相关电位(ERP)的表现与临床参量的关系。方法用NicoletVikingTV型肌电图/诱发电位仪对30例2型DM患者(DM组)及年龄和性别与之匹配的本院医务人员正常人30例(对照组)进行VEP,BAEP,SEP,ERP检测。应用SPSS统计软件分析DM组的EP表现及其与临床参量(病程、血糖、血脂、肾功能、血管病变)的关系。结果DM组(1)VEP异常20例,BAE异常18例,MNSEP异常为20例,PTNSEP异常22例,ERP异常1例。(2)VEP的P100潜伏期(PL)明显延长,BAEP的左侧Ⅰ波PL、双侧Ⅴ波PL,波幅(Amp)和各波间期(IPL)明显异常,SEP周围电位N9至皮层电位P25/P38的PL,Amp以及ERP中N2,P3a,P3b的PL,Am都有明显异常,与对照组比较(F=5.131～45.213,t=2.695～3.472P<0.05～0.01)。(3)EP改变与各临床参量有关。结论DM患者VEP,BAEP,SEP,ERP都有不同程度异常。异常程度和病程平行。     

Experience and Implantation Techniques with a New Single-Pass Lead VDD Pacing System

Thirty-six patients were implanted with a single-lead atrial-synchronous ventricular pacing (VDD) system at our center in the first and second phases of a clinical trial between October 1987 and December 1989. The clinical system comprised a pulse generator in conjunction with a pacing lead incorporating two diagonal atrial bipolar (DAB) electrodes designed to lie in the mid-to upper-right atrium and a distal tip electrode for ventricular pacing and sensing. Twenty five of the patients had complete heart block, ten had second-degree block, and one had AV nodal block. A modified Bruce protocol limiting treadmill speed to 1.7 miles per hour was used to establish sinus node competency as evidenced by sustained sinus rate increase in a more-or-less linear fashion. The mean acute P wave amplitude measured at implant was 1.66 mV +/- 1.04 SD; the mean P wave amplitude (minimum and maximum, both sitting and supine) for all patients at all follow-up (N = 420) was 1.54 mV +/- 0.9 SD. The follow-up interval for all patients ranged from a minimum of 13 days and a maximum of 762 days, with a mean of 261 +/- 206 days as of December 1, 1989. Four dislodgments of the ventricular electrode occurred with the more pliable of two passive fixation mechanisms used on the lead; atrial sensing remained intact at all times with both fixation systems. Changes in atrial sensing threshold were quite frequent during the early follow-up visits due to electrode movement in the right atrium; however, adequate ventricular tracking of the atrial rate was achieved in all cases once the threshold values were established initially, even though several patients required atrial sensing of 0.2 mV at some of the follow-up visits. Two patients presented with pacemaker-mediated tachycardia associated with retrograde conduction, which was resolved with reprogramming; they are presently maintaining atrial synchrony in the VDD mode. Successful single-lead VDD pacing with consistent P wave sensing has been achieved with this atrial rate responsive system.