Ictal tachycardia its discriminating potential between temporal and extratemporal seizure foci

1、Ictal tachycardia: its discriminating potential between temporal and extratemporal seizure foci發(fā)作性心動(dòng)過(guò)速：顳葉及顳葉外致癇灶間的潛在差別A wide variety of CNS lesions have been associated with changes in heart rate (HR). However, in epileptic patients their value to lateralize seizure onset remains controversial. This

2、 study aims to assess if HR changes associated with partial onset seizures could be useful in lateralizing seizure onset.許多中樞神經(jīng)系統(tǒng)病灶與心率變化相關(guān)。但是，在癲癇患者中，他們對(duì)于發(fā)作開(kāi)始定側(cè)價(jià)值仍然是有爭(zhēng)議的。這研究旨在評(píng)估是否與部分發(fā)作開(kāi)始相關(guān)的心率變化在發(fā)作開(kāi)始定側(cè)方面是有用的。We analysed HR changes on 100 seizures from 38 consecutive patients (mean age: 27.5 years) adm

3、itted for video-EEG telemetry monitoring. We evaluated the RR interval 30 seconds before the seizure onset and 10, 20 and 120 seconds after the onset. We assessed whether there was a correlation between HR changes and seizure type, left/right differences and different semiological components for eac

4、h seizure.我們分析了行視頻腦電監(jiān)測(cè)的38例連續(xù)患者（平均年齡：27.5）100次發(fā)作心率變化。我們?cè)u(píng)估了發(fā)作開(kāi)始前30秒R-R間期以及發(fā)作開(kāi)始后10秒、20秒以及120秒R-R間期。我們?cè)u(píng)估了心率變化與發(fā)作類(lèi)型，左右側(cè)差別，每次發(fā)作不同的癥狀學(xué)表現(xiàn)之間是否有相關(guān)性。We recorded 100 seizures. Three non-lateralized seizures were excluded from the analysis; 63/97 (65%) had left hemisphere onset, mainly from the temporal lobe (57

5、.7%). The mean baseline HR was 77 beats per minute Ictal tachycardia (HR: 107.06 beats per minute) was detected in 32 seizures, with ictal onset from the mesial temporal lobe structures in 23/32; 16/32 occurred during the first 10 seconds and 16/32 during the next 20 seconds from the seizure onset i

6、ndependently of the site of origin. Among the different semiological components for each seizure, only dystonic posturing and automatism correlated with HR increments. We did not find bradycardia in our series.我們記錄了100次發(fā)作。三次非單次發(fā)作從分析中被排除。63/97（65%）有左側(cè)半球區(qū)起始發(fā)作，主要來(lái)自顳葉（57.7%）。平均基線心率是每分鐘77次，觀察到32次發(fā)作中有發(fā)作性心

7、動(dòng)過(guò)速（HR：107.06次/分），這32次發(fā)作中有23次發(fā)作開(kāi)始來(lái)源于顳葉內(nèi)側(cè)結(jié)構(gòu)，這32次發(fā)作中有16次發(fā)生在起源區(qū)獨(dú)立癲癇發(fā)作開(kāi)始第一個(gè)10秒，剩余16次發(fā)生在接下來(lái)20秒。在每次發(fā)作的不同癥狀學(xué)表現(xiàn)中，僅僅姿勢(shì)性肌張力障礙和自動(dòng)癥與心率增量相關(guān)。在我們的研究中我們沒(méi)有發(fā)現(xiàn)心動(dòng)過(guò)緩。Ictal tachycardia occurs most frequently with seizures arising from the mesial temporal lobe and it may not reliably predict the lateralization of seizure

8、onset.發(fā)作性心動(dòng)過(guò)速最常發(fā)生于顳葉內(nèi)側(cè)起始區(qū)發(fā)作，并且它可能無(wú)法可靠地預(yù)測(cè)發(fā)作開(kāi)始區(qū)的定側(cè)。Key words: heart rate; epilepsy; ictal onset.關(guān)鍵詞：心率、癲癇、發(fā)作期開(kāi)始 INTRODUCTION背景介紹The putative role of the cerebral hemispheres in modu-lating the autonomic cardiac balance is still poorly un-derstood. Along with other higher cortical functions, hemispheri

9、c lateralization in cardiac autonomic con-trol has been suggested based upon the observation of heart rate and/or blood pressure changes following brain lesions, but these changes do not directly reflect the intrinsic cardiac sympathovagal regulation1. Such differences may result from different left

10、/right cere-bral hemispheric influences upon the brainstem auto-nomic centers and can be evaluated by cerebral inac-tivation or stimulation2. Such changes have been re-ported following a wide variety of brain lesions includ-ing stroke, epilepsy, cerebral trauma, encephalitis and brain tumors.大腦半球在調(diào)節(jié)

11、自主神經(jīng)心臟平衡方面上的假定的作用仍被理解地很差。與其他更高級(jí)的皮質(zhì)功能一起，大腦半球在心臟自主神經(jīng)控制方面上的定側(cè)被認(rèn)為是建立在腦損傷后心率或血壓變化基礎(chǔ)之上，但是這些變化不能直接反應(yīng)固有的心臟交感迷走調(diào)節(jié)。這些不同可能源于左/右側(cè)大腦半球?qū)δX干自主神經(jīng)中心不同影響以及能夠被腦失活或刺激所評(píng)估。這些變化被報(bào)道說(shuō)發(fā)生在各種各樣的腦損傷后包括卒中，癲癇，腦外傷，腦炎和腦部腫瘤。In epileptic patients most of these disturbances, seen primarily in the form of tachycardia, could be drug rela

12、ted3 and have been reported following both complex partial seizures (CPS) and simple partial seizures (SPS). Furthermore, the association between heart rate (HR) changes and sudden unexpected death in epileptic patients (SUDEP) has been suggested by case reports of patients with temporal lobe epilep

13、sy and unexpected death46 . Pathological cases, as well as animal models proposed to explain SUDEP, sug-gest that diffuse extratemporal and/or bilateral mesial temporal damage in epileptic patients could interfere with descending forebrain pathways that have influ-ence on cardiovascular regulation,

14、accounting for HR variability. Nevertheless, its semiological value to lat-eralize seizure onset remains controversial in epileptic patients.在癲癇患者中大多數(shù)紊亂主要見(jiàn)于心動(dòng)過(guò)速的形成中，可能是藥物相關(guān)性的，被報(bào)道出現(xiàn)在復(fù)雜部分發(fā)作和簡(jiǎn)單部分發(fā)作之后。另外，心率變化和癲癇猝死之間的關(guān)系是通過(guò)顳葉癲癇患者和猝死的案例報(bào)道表明的。病理報(bào)道，同動(dòng)物模型一樣，被用來(lái)解釋癲癇猝死，表明癲癇患者中彌漫性顳葉外或雙側(cè)顳葉內(nèi)側(cè)損害干擾前腦下行通路，前腦下行通路能夠?qū)π难?/p>

15、管調(diào)節(jié)有影響，對(duì)心率變異性作出解釋。然而，它對(duì)發(fā)作起始區(qū)定側(cè)的癥狀學(xué)價(jià)值在癲癇患者中仍然是有爭(zhēng)議的。It is well known that 2530% of epileptic patients are not adequately controlled with medical therapy and these represent the group of refractory patients7. For some of these patients epilepsy surgery is considered, and a thorough work up is used in o

16、rder to identify the epileptogenic zone. Clinical semiology is one of the parameters used for such lateralization, although the lateralizing value for some of the clinical manifesta-tions remains controversial.眾所周知，25-30%癲癇患者不能被醫(yī)學(xué)治療充分控制，且這些代表難治性患者一組。這些患者中有一部分可以考慮手術(shù)，全面工作被用來(lái)確定致癇灶。臨床癥狀學(xué)被用于這樣定側(cè)參數(shù)之一，盡管一些

17、臨床表現(xiàn)的定側(cè)價(jià)值仍然是有爭(zhēng)議的。The objective of the present study was to evalu-ate if heart rate changes associated with partial onset seizures could be helpful in lateralizing ictal onset.當(dāng)前研究的目的是為了評(píng)估與部分發(fā)作起始相關(guān)的心率變化在發(fā)作起始定側(cè)上是否是有幫助的。MATERIALS AND METHODS材料和方法We analysed HR changes on 100 consecutive CPS from 38 epi

18、leptic patients referred to our center for video-EEG monitoring. Most of these cases were ad-mitted to our unit to define suitability for epilepsy surgery. All patients studied had no history or evidence of an active cardiovascular disease, diabetes, uremia or any other disorder that might affect th

19、e autonomic ner-vous system. In order to be included in the study, base-line heart rate had to be below 120 bpm, and patients had to be on no other medication than antiepileptic drugs (AEDs).我們分析了視頻腦電監(jiān)測(cè)中心選取的38例癲癇患者100次連貫性復(fù)雜部分發(fā)作的心率變化。大多是病例被承認(rèn)進(jìn)入我們單元來(lái)確定手術(shù)是否適合。受試者沒(méi)有活動(dòng)性心血管病，糖尿病，尿毒癥或者可能影響自主神經(jīng)系統(tǒng)的任何一種紊亂的既往史

20、或者證據(jù)。這項(xiàng)研究的入選標(biāo)準(zhǔn)是基線心率是低于120次/分，且患者除了抗癲癇藥以外沒(méi)有其他治療。Scalp EEG was performed with electrodes applied following the 1020 International System, plus two additional sphenoidal electrodes. Electrodes monitor-ing eye movements and chest electrodes for EKG leads were also used. One patient was also recorded wit

21、h in-dwelling depth electrodes. All patients had a negative brain MRI ruling out the presence of a progressive lesion.頭皮腦電采用應(yīng)用電極安裝，履行10-20國(guó)際系統(tǒng)，加上2個(gè)額外的蝶骨電極。監(jiān)測(cè)眼動(dòng)電極以及心電圖的胸腔電極也被使用。一名患者也用顱內(nèi)深部電極記錄。所有患者腦部MRI陰性，排除了進(jìn)行性病灶的存在。We measured the RR interval for the 60 seconds that preceded the seizure onset and th

22、ereafter at 10, 20 and 120 seconds after ictal onset. Ictal onset was defined both clinically and electrographically. From the electrographical point of view we classified tem-poral onset seizures as mesial or neocortical, based on the patterns recently described by Pacia and Eber-sole8. The first o

23、f these patterns, accepted as a mesial pattern, is characterized by a regular 59 Hz activ-ity localized over subtemporal and/or anterior tem-poral areas. The second pattern, highly associated with neocortical temporal lobe onset, is character-ized by low-voltage, high-frequency discharges in the bet

24、a and gamma range with slow and irregular corti-cal rhythms following seizure onset. This activity can be focal or regional temporal. Semiological analyses included the presence and type of aura, type of au-tomatisms, dystonic posturing and the presence of sec-ondarily generalized tonicclonic seizur

25、e. Only those seizures without motor manifestations at the onset were considered for analysis in order to rule out their influence upon heart rate.我們測(cè)量了發(fā)作開(kāi)始前60秒R-R間期，隨之發(fā)走開(kāi)始后10秒，20秒，120秒R-R間期。發(fā)作開(kāi)始是通過(guò)臨床和腦電圖來(lái)確定的。從腦電圖觀點(diǎn)來(lái)看，我們將顳葉起始區(qū)發(fā)作分類(lèi)為內(nèi)側(cè)或新皮層，基于被Pacia and Eber-sole近來(lái)所描述的模式。這些模式中第一個(gè)模式，作為內(nèi)側(cè)模式被接受，是由定位在顳葉下或前

26、顳區(qū)的規(guī)律5-9Hz活動(dòng)為特征的。第二個(gè)模式，與新皮層顳葉起始高度相關(guān)，是以和范圍的低電壓高頻放電以及緊跟發(fā)作起始的規(guī)律皮層節(jié)律為特征的。這一活動(dòng)可能是局灶的或某區(qū)顳葉。癥狀學(xué)分析包括先兆的存在和類(lèi)型，自動(dòng)癥的類(lèi)型，姿勢(shì)性肌張力障礙以及繼發(fā)全身強(qiáng)直陣攣發(fā)作的存在。僅僅那些在起始時(shí)沒(méi)有運(yùn)動(dòng)臨床表現(xiàn)的發(fā)作才被用作分析，目的是為了排除運(yùn)動(dòng)對(duì)心率的影響。A mean baseline HR was estimated (B-HR) and thereafter at 10, 20 and 120 seconds after seizure on-set. Mean differences compar

27、ed to B-HR were as-sessed with a non-parametric variable test (Wisconsin test). B-HR 2SD was used to define significance at a P level 0.05. This value was used to examine each particular seizure, assessing if it produced ictal HR changes. Finally, we attempted to correlate HR changes and left/right

28、side differences, electrograph-ical onset and the semiological components for each seizure.平均基線心率被評(píng)估，隨之發(fā)作開(kāi)始后10秒，20秒以及120秒心率被評(píng)估。與基線心率相比較，平均差別被沒(méi)有參數(shù)的變量分析所評(píng)估?；€心率2標(biāo)準(zhǔn)差被用作定義一個(gè)P0.05的重要性。這一價(jià)值被用作監(jiān)測(cè)每一種特定類(lèi)型，評(píng)估是否產(chǎn)生發(fā)作性心率變化。最后，我們?cè)噲D將心率變化和左/右側(cè)差別，每次發(fā)作腦電圖上發(fā)作開(kāi)始以及癥狀學(xué)表現(xiàn)相關(guān)聯(lián)。RESULTS結(jié)果We included 38 patients (18 male and 2

29、0 female, mean age: 27.6 years, range: 353 years). Eleven patients had a single seizure whereas 27 had multiple seizures during the recording. All patients had consistent HR changes from seizure to seizure. General physical and neurologic examinations were unremarkable ex-cept for eight out of 37. A

30、ll patients were exposed to AED therapy with plasma levels within the therapeutic range. (See Table 1 for demographic information.)我們包括38例患者（18名男性以及20名女性，平均年齡27.6歲，范圍3-53歲）。在記錄期11名患者有單一發(fā)作，而27名患者有多種發(fā)作。所有患者從發(fā)作到發(fā)作有持續(xù)的心率變化。一般生理學(xué)和神經(jīng)學(xué)檢查是不起眼的，除了37例特例。所有患者在抗癲癇藥物治療且血漿水平在治療范圍內(nèi)。Brain MRI detected morphologic a

31、lteration in 25 out of 37 cases. In 23 cases focal lesions were doc-umented, including hippocampal sclerosis (n D 16), sequelae from previous surgery for cerebral neoplasm (n D 2) or trauma (n D 1) and gray matter heterotopy (n D 4).腦部MRI發(fā)現(xiàn)：37例中25例有形態(tài)學(xué)上的改變。23例中局灶性病灶被記錄到，包括海馬硬化（16例），腦部腫瘤先前手術(shù)的后遺癥（2例），

32、腦外傷（1例），灰質(zhì)異位（4例）。We were able to lateralize seizure focus in 97 seizures, thus excluding the other three, for statisti-cal analysis. The mean B-HR was 77 bpm, and the mean HR at 10, 20 and 120 seconds after seizure on-set was 88.8, 95.1 and 93.5 bpm, respectively. The mean HR was significantly modif

33、ied from baseline at 10 ( P D 0:001), 20 ( P D 0:003) and 120 ( P D 0:002) seconds.我們能夠給97次發(fā)作致癇灶定側(cè)，因此為了統(tǒng)計(jì)分析，排除了其他3次發(fā)作。平均基礎(chǔ)心率是77次/分，發(fā)作開(kāi)始后10秒、20秒、120秒平均心率分別是88.8,95.1,93.5次/分，在發(fā)作后10秒，20秒，120秒時(shí)的平均心率是從基線處作了重大調(diào)整。（ 分別是P=0.001,P=0.003,P=0.002）HR was raised in 32 seizures (32.9%), half of them within the fi

34、rst 10 seconds from seizure onset and the remaining within the first 20 seconds. We found no ic-tal bradycardia or interictal heart rate disorders in our patients. Analysis of HR at 120 seconds from ictal on-set showed changes only in those cases with secondar-ily tonicclonic activity.心率增快出現(xiàn)在32次發(fā)作中（

35、32.9%），他們中一半出現(xiàn)在發(fā)作開(kāi)始起的第一個(gè)10秒內(nèi)，剩余一半出現(xiàn)在接下來(lái)的20秒內(nèi)。在我們的患者中我們沒(méi)有看到發(fā)作性心動(dòng)過(guò)緩或者發(fā)作間期心率紊亂。發(fā)作開(kāi)始起120秒時(shí)的心率分析顯示變化僅僅出現(xiàn)在繼發(fā)強(qiáng)直-陣攣活動(dòng)的那些病例中。1、HR changes in relation to hemispheric lateralization與大腦半球定側(cè)相關(guān)的心率變化Sixty-five percent of the seizures lateralized to the left hemisphere and the remaining to the right. Con-sidering o

36、nly those seizures with ictal HR changes, 10/32 (31.2%) were right-sided and 22/32 (68.8%) left-sided. These percentages were also seen for those seizures without HR changes.We found no statistical differences between both groups in relation to lateral-ization (Fig. 1).65%的發(fā)作定側(cè)在左側(cè)大腦半球，剩余定側(cè)在右側(cè)大腦半球?？紤]

37、到僅僅伴有發(fā)作性心率變化的那些發(fā)作，10/32（31.2%）是定側(cè)在右側(cè)的，22/32（68.8%）是定側(cè)在左側(cè)的。這些百分比也見(jiàn)于那些沒(méi)有心率變化的發(fā)作中。與定側(cè)相關(guān)的組組之間我們沒(méi)有發(fā)現(xiàn)統(tǒng)計(jì)學(xué)差異。Ictal tachycardia does not lateralize seizure onset發(fā)作性心動(dòng)過(guò)速?zèng)]有定側(cè)發(fā)作起始2、HR changes related to seizure focus與致癇灶相關(guān)的心率變化Seizure onset defined by ictal EEG findings was as follSeizure onset defined by ictal

38、 EEG findings was as follows: 41/97 seizures were extratemporal and 56/97 had temporal onset. In the latter group, 40/56 had elec-trographic patterns suggestive of mesial temporal on-set, whereas the onset was defined as neocortical in the remaining 16.通過(guò)發(fā)作期腦電圖發(fā)現(xiàn)定義的發(fā)作起始如下：97次發(fā)作41次是顳葉外，56次是顳葉起始。在后面這組

39、中，56次發(fā)作中有40次被認(rèn)為是顳葉內(nèi)側(cè)起始的腦電圖模式，然而剩余16次發(fā)作起始被定義為新皮層。Considering the relationship between seizures with HR changes and seizure onset, we found that the ma-jority of these seizures (25/32) had temporal onset. Looking for differences between mesial and neocor-tical origin, we found that the mesial group wa

40、s re-sponsible for changes in 23/25 (92%).考慮到心率變化和發(fā)作開(kāi)始間的關(guān)系，我們發(fā)現(xiàn)這些發(fā)作中大多數(shù)（25/32）是顳葉起始。查看內(nèi)側(cè)和新皮層起源之間的差別，我們發(fā)現(xiàn)內(nèi)側(cè)組對(duì)在25次發(fā)作中有23次（92%）心率變化負(fù)有責(zé)任。The analysis of those seizures without HR changes showed that 34/65 (52.3%) had an extratemporal focus and 31/65 (47.7%) a temporal one, without a signifi-cant differe

41、nce between mesial and neocortical onset.沒(méi)有心率變化的那些發(fā)作分析顯示65次發(fā)作34次（52.3%）有一個(gè)顳葉外病灶，65次發(fā)作31次（47.7%）有一個(gè)顳葉病灶，在內(nèi)側(cè)和新皮層起始之間沒(méi)有重大差別。In summary, the only difference statistically signif-icant was the one that linked temporal lobe onset and HR changes (Fig. 2).總而言之，統(tǒng)計(jì)學(xué)上惟一重大不同是顳葉起始和心率變化之間的聯(lián)系。3、HR changes related

42、to semiological findings與癥狀學(xué)發(fā)現(xiàn)相關(guān)的心率變化We found that 17/32 (53.1%) seizures with HR changes had a clear aura, 28/32 (87.5%) automatisms and 19/32 (59.4%) dystonia. A similar analysis for those seizures without HR changes showed an aura in 23/65 (35.4%), automatisms in 29/65 (44.6%) and dystonia in 14/

43、65 (21.5%) (Fig. 3).我們發(fā)現(xiàn)了32次伴有心率變化的發(fā)作17次（53.1%）有一個(gè)清晰的先兆，這32次中28次（87.5%）有自動(dòng)癥，這32次中19次（59.4%）有肌張力障礙。沒(méi)有心率變化的那些發(fā)作的一個(gè)相似分析顯示65次發(fā)作中23次（35.4%）有一個(gè)先兆，65次發(fā)作中有29次（44.6%）有自動(dòng)癥以及65次發(fā)作中有14次（21.5%）有肌張力障礙。Finally, we found no association between HR changes and age, sex or pharmacological therapy ad-ministered.最后，我們發(fā)現(xiàn)

44、心率變化和年齡，性別或者管理的藥理學(xué)治療沒(méi)有關(guān)系。DISCUSSION討論One of the most striking findings in the present study is the significant percentage of partial onset seizures presenting with increased HR as an ictal manifesta-tion. Moreover, these changes seem to have a more robust association with partial seizures arising fr

45、om the temporal lobe, especially from mesial structures. However, our findings failed to support a positive cor-relation between cardiac changes and side of the ic-tal discharge suggesting that, although present in some cases, they have no predictive value to assess lateral-ization.當(dāng)前研究最突出的發(fā)現(xiàn)之一是呈現(xiàn)增快

46、的心率作為一個(gè)發(fā)作性臨床表現(xiàn)的部分起始發(fā)作占了重大百分比。而且，這些變化似乎與起源于顳葉尤其是內(nèi)側(cè)結(jié)構(gòu)的部分發(fā)作部分發(fā)作有更密切關(guān)系。但是，我們的發(fā)現(xiàn)沒(méi)能支持心臟變化和發(fā)作期放電一側(cè)之間的正性相關(guān)，這表明盡管一些病例有呈現(xiàn)相關(guān)性，但是我們的發(fā)現(xiàn)表明他們沒(méi)有評(píng)估定側(cè)的預(yù)測(cè)價(jià)值。Although in the present study we observed no dif-ferences between left-sided onset with or without HR changes, we have to recognize that these figures might refle

47、ct a sample bias, given that 65% of the anal-ysed seizures were left-sided in origin. Furthermore, our results showed that 78% of the seizures with ic-tal tachycardia were seen in patients with temporal lobe epilepsy, especially those with electrographic on-set from mesial structures, which accounts

48、 for 92% of the events with temporal onset. This finding, along with the presence of automatisms and dystonia, semio-logical features mostly seen with mesial temporal lobe epilepsy, reached statistical significance.盡管在當(dāng)前研究我們發(fā)現(xiàn)左側(cè)半球起始發(fā)作伴或不伴心率變化之間沒(méi)有區(qū)別，但是我們不得不承認(rèn)這些數(shù)據(jù)可能反映一個(gè)樣本偏倚，考慮到被分析的發(fā)作中65%是左側(cè)起源。另外，我們的結(jié)果

49、顯示伴有發(fā)作性心動(dòng)過(guò)速的發(fā)作中78%見(jiàn)于顳葉癲癇患者，尤其是那些腦電圖起始于內(nèi)側(cè)結(jié)構(gòu)的患者，這為92%的顳葉起始事件作出了解釋。這一發(fā)現(xiàn)，與自動(dòng)癥和肌張力障礙存在一起，癥狀學(xué)特征更多見(jiàn)于顳葉內(nèi)側(cè)癲癇，達(dá)到了統(tǒng)計(jì)學(xué)意義。Our findings agree with several other reports, in spite of the fact that different methods were used to evaluate the relationship between seizures and HR changes. Li et al.4 observed tachycar

50、dia in 39% of their patients with CPS from temporal lobe epilepsy, but found no differences regarding lateralization. Sim-ilar conclusions were reported by Galimberti et al.6. Blumhardt and his group9 have also seen sinus tachy-cardia in 92% of their patients with temporal lobe epilepsy, whereas Mar

51、shall et al.10 observed a similar incidence rate in video-EEG evaluation of CPS. Con-trary to the present study, the possibility to lateralize seizure onset has been proposed through both clinical and experimental studies. Fang et al.11 found that the electrical stimulation of the right hypothalamus

52、 trig-gers a significant cardioacceleration in dogs, whereas the stimulation of the left hypothalamus resulted only in a moderate response. Asymmetrical autonomic in-nervation of the heart and lateralization of cardiac sympathetic outflow in the brainstem has also been re-cently suggested by Hachins

53、ki et al.12 using a stroke animal model. They found that right hemispheric in-farcts produced a greater increase in sympathetic nerve discharge, plasma norepinephrine, and duration of the QT interval of the EKG. In studies performed during an intracarotid amytal test, both Hachinskis1 and Zam-rinis2

54、 groups found an increased HR after the inacti-vation of the left hemisphere by an intracarotid injec-tion of amobarbital, whereas a reduction in HR was seen after inactivation of the right hemisphere. Thisobservation provides support for the hypothesis that the autonomic response might be disinhibi

55、ted with le-sions in the contralateral hemisphere5. Given that the major effects of an intracarotid amobarbital injection are in the distribution of the ipsilateral anterior and middle cerebral arteries, the changes in HR appear to be produced by a suprabulbar inactivation, so it does not represent

56、a discrete focus, similar to what happens during a seizure. In addition, these reports were done with a small number of subjects, so that changes could be not statistically significant. Oppenheimer et al.13 suggested a right-sided dominance for sympathetic ef-fects in humans by stimulation of the in

57、sular cortex. However, simple observation of the HR or blood pres-sure level may not be an accurate method for assess-ing cardiac sympathovagal balance. In a recent report by Swartz and colleagues14 based on patients under-going electroconvulsive therapy (ECT), they showed a significant and more per

58、sistent HR elevation with right than with left side stimulation. This observation agrees with the predominantly right-sided mechanisms that mediate sympathetic cardioacceleration and with the theory that the cardioacceleratory sinoatrial heart node is innervated by a greater number of sympathetic fi

59、bers arising from the right side of the brain14. It is im-portant to consider that these HR changes can result from a summation of effects. The seizures triggered by ECT are linked not only to ictal discharges that in-volve widespread cortical areas, but also to endocrine mechanisms, such as epinephrine liberation. This un-derlying pathophysiological process is rather different from the one seen with CPS, where seizures