Predictivity of Plasma Prolactin Levels in Differentiating Epilepsy from Pseudoseizures: A Prospective Study

The predictivity of raised plasma prolactin (PRL) concentrations in differentiating seizure from syncopal attack was prospectively assessed in all patients consecutively admitted to the Clinica Neurologica of Brescia, Italy in a 12-month period who fulfilled the criteria for either a seizure or syncopal attack. Postictal plasma prolactin concentration (P1) was assessed as soon as possible after the event. Three further assessments were performed: P2 was sampled 1 h after P1, P3, and P4 were sampled in the morning for the next 2 days. Patients who had had a seizure showed significantly increased P1 concentrations, when P1 was sampled within 60 min of the attack. In seizure patients assessed >1 h after the event, P1 was not significantly different from either P2, P3, or P4. In patients who had had a syncopal attack, PRL concentration never increased. In patients assessed ≤60 min after the seizure, cutoff criterion of P1 exceeding by + 3 SD the mean calculated on P2, P3, and P4 yielded a positive predictive value of 89% and a negative predictive value of 61%. These findings confirm that plasma prolactin concentration is highly predictive of true epilepsy but barely predictive of pseudoseizures.     

Vasodepressor reactions after orthotopic cardiac transplantation: Relationship to reinnervation status

Ventricular vagal nerve endings are thought to trigger vasodepressor syncope. Reports of vasodepressor reactions associated with donor bradycardia after cardiac transplantation have led to speculation that vagal reinnervation occurs. We assessed reinnervation status in seven patients 23–36 months (median 24 months) post-transplantation. Heart rate responses to vagal manoeuvres (respiration, Valsalva) and sympathetic stimuli (exercise and injection of tyramine into the coronary artery supplying the sinus node) were measured. All patients underwent 60 min of 60° head-up tilt with foot plate support. During tilt four of the seven had vasodepressor reactions with a fall in mean arterial pressure of 20–90 mmHg. During vasodepression two patients had falls in donor heart rate of 13 and 40% relative to peak heart rate during tilt. These two patients had evidence of functional sympathetic reinnervation. By contrast the two patients without donor bradycardia during vasodepression had only limited or no evidence of sympathetic reinnervation. No patient had consistent evidence of parasympathetic reinnervation as judged by the heart rate response to vagal manoeuvres. Headup tilt can thus produce vasodepressor reactions with donor bradycardia after cardiac transplantation in the absence of consistent evidence of vagal reinnervation. Left ventricular nerve endings may not be the only mediators of tilt-induced vasodepressor reactions in man. Donor bradycardia during vasodepression may reflect sympathetic withdrawal and not vagal reinnervation.     

直立倾斜试验加硝酸甘油含化诊断血管迷走性晕厥的临床研究

目的评价硝酸甘油(NTG)含化加异丙肾上腺素倾斜试验(ITTT)诊断血管迷走性晕厥(VS)的价值.方法将72例VS患者和36例正常对照组随机均分成ITTT和ITTT+NTG组.结果ITTT+NTG组敏感性高于ITTT(93.1%和76%,P＜0.05)有显著性差异.结论ITTT+NTG含化是一种安全、耐受性好、敏感性高,特异性强的诊断VS的方法.     

Observations on the arterial baroreflex in neurally mediated vasodepressor syncope

The arterial baroreflex was studied in subjects who had recently had an episode of vasodepressor syncope. This was determined using 2–3 mcg/kg intravenous boluses of phenylephrine and assessing the bradycardic response. The values were measured in ms/mmHg and expressed as the angular coefficient of the regression line between the increase in R—R interval on the electrocardiograph and the systolic arterial pressure. In subjects examined immediately after the vasodepressor syncope episode the bradycardic response was much more marked than in controls (p < 0.01) and in the subjects themselves 6 months after the episode, provided that they were symptom-free (p < 0.01). It is concluded that in vasodepressor syncope there is a phase in which the baroreflex is highly sensitive and that this is due not to a lowering of the stimulation threshold but to a gain in the efferent arc, which explains a vagotonic response.     

Ondine's curse and neurally mediated syncope -- a new and important association

A 6-year-old boy with congenital central hypoventilation syndrome(Ondine's curse) presented with presyncope. Investigation revealeda diagnosis of neurally mediated syncope. This previously unreportedassociation provides strong evidence that autonomic dysfunctionis implicated in both these conditions.     

儿童不明原因晕厥的临床特征与直立倾斜试验关系的研究

目的　分析直立倾斜试验阳性与不明原因晕厥患儿临床特征的关系。方法　对 47例不明原因晕厥患儿 ,根据其直立倾斜试验的结果分为二组 :直立倾斜试验阳性组和阴性组 ,将其临床特征进行对比分析研究 ,并对其各个临床特征与直立倾斜试验的结果进行Logistic回归分析。 结果　不明原因晕厥患儿的性别、年龄、有无晕厥诱因及有无晕厥先兆对直立倾斜试验的结果有影响 ,根据Logistic回归分析 ,对直立倾斜试验结果有显著影响的因素依次为晕厥诱因、晕厥先兆和年龄。结论　对于发生于青春期女孩不明原因的晕厥 ,而患儿又有较明确的晕厥诱因和晕厥先兆者 ,其直立倾斜试验阳性的可能性较大 ,临床可诊断为血管迷走性晕厥。     

基础直立倾斜试验对儿童不明原因晕厥的诊断研究

为探讨基础直立倾斜试验对不明原因的晕厥患儿的诊断价值，应用直立倾斜试验（倾斜角度６０度，试验持续时间４５分钟）对４２例不明原因的晕厥患儿进行诊断研究，并以１３名正常小儿作对照。结果：基础直立倾斜试验在不明原因晕厥患儿的阳性率为６７％，对照组阳性率为０。诊断敏感度、特异度及诊断价值分别为６７％、１００％及７４％。阳性反应诱发时间为２２±１２分钟。在２８例阳性反应患儿中，１５例为血管抑制型反应，表现为血压明显下降，心率增快；３例为心脏抑制型反应，表现为心率明显下降，血压不变；１０例为混合型反应，其血压、心率均明显下降。提示：基础直立倾斜试验可较好地、客观地对血管迷走性晕厥进行诊断。     

直立倾斜试验对血管迷走神经性晕厥的诊断价值

目的　探讨直立倾斜试验对血管迷走性晕厥的诊断价值及其局限性。方法　对 12 9例不明原因晕厥患者及 5 4名无晕厥病史健康对照者进行直立倾斜试验 ,先进行基础倾斜试验 (倾斜 70°、持续 30 min) ,阴性者再进行两阶段的异丙肾上腺素的激发试验。结果　 112 9例晕厥患者中 ,倾斜试验阳性者 88例 (阳性率 6 8.2 % ) ,5 4名对照组中阳性者 6名 (阳性率 11.1% ) ,晕厥组阳性率明显高于对照组 ,差异有显著性 (P<0 .0 0 5 )。本次试验的灵敏度 6 8.2 % ,特异度 88.9%。 2患者年龄越大阳性反应率越低 (P<0 .0 5 ) ,性别对试验的阳性反应率影响不显著 (P=0 .31)。结论　倾斜试验设备简单、易于操作、是血管迷走性晕厥的一项比较安全有效的诊断方法。     

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目的探讨米多君对血管迷走性晕厥儿童的治疗效果。方法将2003-07—2004-12在北京大学第一医院儿科就诊的46例晕厥反复发作、直立倾斜试验(HUT)阳性的血管迷走性晕厥患儿,分为米多君组、美托洛尔组及基础治疗组。首先应用HUT评价患儿的治疗反应及调整药物,所有患儿随访6个月后,如没有晕厥的发作者则停药,并继续随访。进一步评价患儿晕厥复发情况及药物的不良反应。结果米多君组、美托洛尔组及基础治疗组3组患儿HUT转阴率分别为75·0%、65·0%及20·0%。米多君组及美托洛尔组患儿的HUT转阴率明显高于基础治疗组(P均<0·05),而给药治疗的两组患儿的HUT转阴率差异无显著性(P>0·05)。在随访过程中,米多君组及美托洛尔组晕厥复发率分别为22·2%及30·7%,而基础治疗组的晕厥复发率为80·0%,前两组晕厥复发率显著低于后组(P均<0·05)。前两组之间的复发率差异无显著性(P>0·05)。结论米多君可有效治疗血管迷走性晕厥儿童。