原发性肝癌肝外动脉供血及其临床治疗意义

目的:探讨原发性肝癌肝外动脉供血类型的分类、一般供血规律及其对临床治疗的意义。方法:回顾性分析185例原发性肝癌患者行经导管肝动脉化疗栓塞(TACE)术的DSA检查结果,对肝外动脉供血类型进行分类。结果:185例患者中存在215条肝外供血动脉,采用三分类法将其分为3类:1.变异肝动脉供血130条,占60.47%;2.肝动脉通畅肝外侧支供血35条,占16.28%;3.肝动脉闭塞或狭窄肝外侧支供血50条,占23.26%。其中后2类为非肝动脉供血。第1类以第1次TACE术时发现为主,第2类及第3类以第3次及以后TACE术时发现为主。非肝动脉供血与肝动脉通畅与否有关系。结论:原发性肝癌肝外动脉供血三分类法是一种较新的分类方法,具有简洁明晰的特点,对分析其类型与TACE术次数及肝动脉通畅与否的关系、指导肝癌的临床治疗具有重要作用。     

肝外供血动脉栓塞在巨块型肝癌治疗中的价值

目的探讨经导管肝外供血动脉栓塞在治疗巨块型肝癌中的价值。方法对35例巨块型肝癌,首次行经导管肝动脉化疗栓塞术（TACE）,第2次及其后在肝动脉TACE基础上加行经右侧胸廓内动脉、右侧肋间动脉侧支供血动脉栓塞术。结果本组35例巨块型肝癌患者,发现肝外侧支49支,对46支使用微导管进行栓塞治疗,3支行超选择灌注化疗。初次TACE治疗时肝外血供多有膈下动脉参与,治疗过程中,随着肿瘤的增大或肝动脉的闭塞,胸廓内动脉、肋间动脉、胰十二支肠动脉弓等血管有可能参与。结论对肝外侧支血管应用微导管超选择栓塞或灌注化疗均能加强TACE在巨块型肝癌治疗中的作用,提高患者带瘤生存期。     

TACE治疗原发性肝癌后并发肝脓肿的影响因素

目的 观察TACE治疗原发性肝癌后并发肝脓肿的影响因素。方法 采用倾向性评分匹配法回顾性收集99例接受TACE治疗的原发性肝癌患者,其中26例TACE后并发、73例未并发肝脓肿;根据治疗方式将其分为传统TACE(cTACE)组(n=48)和药物栓塞微球TACE(DTACE)组(n=51)。比较并发肝脓肿与未并发肝脓肿患者临床资料的差异,以logistic回归分析筛选TACE治疗原发性肝癌后并发肝脓肿的影响因素。结果 TACE治疗原发性肝癌后并发与未并发肝脓肿患者之间,肿瘤供血血管数目、碘油量及栓塞剂种类差异均有统计学意义(P均<0.05)。cTACE组内并发与未并发肝脓肿患者血糖及栓塞剂种类差异有统计学意义(P均<0.05);DTACE组内并发与未并发肝脓肿患者碘油量差异有统计学意义(P<0.05)。TACE治疗原发性肝癌后并发肝脓肿的保护因素为患者年龄<55岁、无靶向药物联合免疫检查点抑制剂治疗史(靶免史)、仅栓塞1支肿瘤供血动脉、碘油量少及仅使用1种栓塞剂,TACE次数≥3则为危险因素(P均<0.05)。结论 患者年龄、靶免史、TACE次数、肿瘤供血血...     

肝癌肝外动脉供血的形成机制与介入治疗的研究

目的研究肝癌肝外动脉供血的形成机制 ,旨在指导介入治疗。方法 10 38例肝癌经动脉化疗栓塞 (TACE)前常规腹腔动脉和肠系膜上动脉造影 ,对癌灶临近膈肌的 10 2例加作选择性膈下动脉造影 ,分析肝癌肝外动脉供血特征。结果 14 7例肝外动脉供血来源于膈下及右肾上腺动脉 5 4例 (36 7% ) ,胃十二指肠及网膜动脉 5 0例 (34 0 % ) ,胃左动脉 2 2例 (15 0 % ) ,胰十二指肠动脉弓 18例 (12 2 % ) ,结肠右动脉 3例 (2 1% )。其中 ,97例为肝癌本身固有的寄生性供血(6 6 0 % ) ,37例为TACE后肝动脉闭塞所致的肝外侧枝循环 (2 5 2 % ) ,其余为肝切缘网膜粘附供血(8 8% )。肝外动脉供血与癌灶的部位和大小密切相关 ,肝外供血支的插管成功率为 82 3%。结论明确肝癌肝外动脉供血的形成机制对临床准确和彻底阻断肝癌多动脉供血 ,提高肝癌介入治疗的效果具有重要的意义。     

探讨肝癌肝外供血的形成规律及介入治疗

目的探讨肝癌的肝外动脉供血规律,插管技术,旨在指导介入治疗。方法分析46例肝癌患者54条肝外动脉供血的特征,对肝外动脉供血支超选插管,并行动脉化疗栓塞术。结果肝外动脉供血与肿瘤部位、大小密切相关;RH、Cobra导管配合SP导管使用,肝外动脉供血支插管成功率为81%。4~6周复查,CT显示肿瘤缩小,碘油沉积致密完全。结论肝癌可有丰富的肝外动脉供血,明确肝癌肝外动脉供血的形成机制对临床准确和彻底阻断肝癌的动脉供血,提高肝癌介入治疗的效果具有重要的意义。     

膈下动脉供血在肝癌介入性栓塞治疗中的价值

目的　探讨膈下动脉对肝癌的供血及其介入性栓塞在肝癌治疗中的价值。　方法　原发性肝癌 35例 ,其中一例为肝癌并发胆道大出血。全部行肝动脉及膈下动脉造影 ,对肝动脉及有参与肝癌供血的膈下动脉分别进行化疗性栓塞治疗 ,胆道出血病例加用明胶海绵和弹簧圈栓塞。　结果　 35例中有 2 1例膈下动脉供血 ,主要为侵犯肝包膜的弥漫型肝癌和巨块型肝癌 ,供血的范围从 2 0 %～ 70 %。治疗后肿瘤缩小 4 0 %～ 5 0 % 14例 ,10 %～ 30 % 18例 ,无变化 3例 ,胆道出血停止。　结论　在肝癌的侧支供血中 ,膈下动脉是主要侧支动脉 ,行肝癌介入治疗需与肝动脉同时进行栓塞     

肝癌血供研究进展

对于不能手术切除的肝脏恶性肿瘤,经血管途径行介入治疗可获得可靠疗效。所以准确的描述肿瘤血供对肝癌的介入治疗就显得尤为重要。近年来研究表明,肝癌血供较为复杂,存在肝动脉、肝外侧支、门静脉供血及肝动脉门静脉双重供血等情况。随着介入治疗次数的增加,肝癌血供亦发生变化。肝癌血供研究直接影响对其介入治疗方式的选择和疗效。     

丝裂霉素联合碘油经肝动脉介入栓塞治疗肝癌的临床疗效研究

正介入治疗作为一种微创疗法是目前公认的肝癌综合治疗的重要方法,它在抑制肿瘤生长,提高患者生存率等方面具有显著效果。近年来,肝癌的介入治疗已有很大发展。肝癌常用的介入疗法包括血管性介入治疗、非血管性介入治疗以及综合性介入治疗。肝癌的介入治疗在我国已开展了约20余年,血管性介入治疗主要包括经肝动脉化疗栓塞(TACE)和经肝动脉灌注化疗(TAI),是目前肝癌介入治疗的主要方法,通过栓塞肿瘤供血动脉达到使肿瘤缺     

网膜动脉栓塞化疗在肝癌治疗中的价值

目的 探讨网膜动脉栓塞化疗在肝癌治疗中的价值.方法 对27例经血管造影确认有网膜动脉参与肝癌供血者行TACE.观察术后临床表现、实验室检查结果和影像学表现,并与血管造影结果进行对照分析.结果 病灶位于肝右叶周边区26例,1例位于肝脏Ⅳ段下部.38支网膜动脉参与肿瘤供血.18例患者网膜动脉被成功栓塞.肝癌破裂出血患者均成功止血,无严重并发症发生.术后7l%(15/21)的患者肿瘤复发.结论 网膜动脉参与肝癌供血常见于多次行TACE并且包块位于肝右叶周边区的患者.网膜动脉行TACE是安全可行的,但肿瘤残留率较高.     

中晚期肝癌肝外供血分析及临床介入治疗

目的探讨肝癌的肝外动脉供血规律及介入治疗。方法92例肝癌患者发现肝外供血动脉105条，分别超选择插管行化疗栓塞。结果中晚期肝癌肝外动脉来源类型分别源于肠系膜上动脉（33．33％）、右膈下动脉（17．14％）、胃十二指肠动脉（14．29％）、左膈下动脉（7．62％）、胃左动脉（6．67％）、右肋间动脉（6．67％）、右肾上腺动脉（4．76％）、脾动脉（4．76％）、右腰动脉（2．86％）和右胸廓内动脉（1．90％）。形成肝外动脉的影响因素较多，包括化疗栓塞的次数、肿瘤在肝内的部位、肿瘤的直径和操作方法。结论肝癌有丰富的肝外动脉供血，对肝外动脉供血支超选择性栓塞治疗，对提高中晚期肝癌患者介入治疗疗效具有重要的临床意义。     

Clinical assessment of hemodynamic values in two surgical intensive care units. Effects on therapy

A prospective study of 126 surgical patients from two institutions was undertaken to assess the impact of pulmonary artery catheterization in surgical intensive care units. Before catheterization, surgical residents were asked to predict pulmonary artery wedge pressure, cardiac output, systemic vascular resistance, and plan of therapy. After catheterization, each chart was reviewed by a panel of intensive care specialists and a general surgeon. Correct classification for the hemodynamic variables ranged from 47% to 55%. Catheterization results prompted a major change in therapy in 50% of patients. The data suggest that hemodynamic variables obtained from pulmonary artery catheterization improve the accuracy of bedside evaluation and lead to alteration in therapy, particularly in patients whose pulmonary artery wedge pressure predictions were poor.     

Association of plasma fibrinogen concentration with vascular access failure in hemodialysis patients.

BACKGROUND: Elevated plasma fibrinogen is an important risk factor for coronary artery disease in the general population and patients with chronic renal failure. High plasma fibrinogen may trigger thrombus formation in arteriovenous fistulas. We performed a prospective, cohort study to evaluate the association of plasma fibrinogen concentration with vascular access failure in patients undergoing long-term haemodialysis. METHODS: Between September 1989 and October 1995, 144 patients underwent a vascular access operation. In March 1997, 102 patients (56 M, 46 F) who had been followed up for more than 18 months (median; 37 months, range; 18-102 months) were included in the study. The median age of the patients was 52 years (range; 19-78 years). In 35 patients, renal disease was secondary to diabetes mellitus. The type of vascular access was a polytetrafluoroethylene (PTFE) graft in 17 patients. Seventy-seven patients received recombinant human erythropoietin (r-HuEPO) therapy during the follow-up period. Plasma fibrinogen, albumin, total cholesterol, hematocrit, platelets and creatinine were measured at the time of operation. Vascular access failure was defined as the occurrence of complications requiring transluminal angioplasty, thrombolytic therapy or surgical repair. RESULTS: Thirty-eight patients had at least one vascular access failure and the incidence was 0.3 (range; 0-2.4) episodes per patient-year. The survival rate of vascular access was 78% (native fistula; 80%, PTFE graft; 71%) after 12 months and 70% (native fistula; 73%, PTFE graft; 51%) after 24 months. Older age, a PTFE graft, r-HuEPO therapy, higher hematocrit, lower albumin and higher fibrinogen levels were significantly associated with vascular access failure, whereas gender, diabetes mellitus, total cholesterol and platelet count were not. Plasma fibrinogen was inversely correlated with albumin (r=-0.38, P=0.001). The cumulative vascular access survival was significantly lower in patients with high plasma fibrinogen levels (> or = 460 mg/dl) compared with patients with low levels (< 460 mg/dl) (P=0.007). Independent risk factors for vascular access failure analysed by Cox's proportional hazards model were older age (RR; 1.36 by 10-year increment), higher fibrinogen level (RR; 1.20 by 100 mg/dl increment), PTFE graft (RR; 2.28) and r-HuEPO therapy (RR; 3.79). CONCLUSION: High plasma fibrinogen level is an independent risk factor for vascular access failure in haemodialysis patients.     

Transcatheter embolization of complex pelvic vascular malformations: results and long-term follow-up

OBJECTIVES: Vascular malformations of the pelvis are rare and present a difficult therapeutic challenge. Surgical treatment is notoriously difficult and carries a high likelihood of recurrence. Surgical proximal ligation of a feeding vessel may in fact be contraindicated, because it can make subsequent transcatheter therapy impossible. The purpose of this study was to review our results with transcatheter embolization therapy in symptomatic complex pelvic vascular malformations in 35 patients. METHODS: A retrospective review was conducted of a prospectively compiled database of all patients undergoing transcatheter therapy of a pelvic vascular malformation at our institution. RESULTS: The mean age of the patients was 34 years (range, 16 months-66 years), and 51% were male. The most common presenting symptoms included pain (59%), a visible or palpable lesion (62%), associated palpable pulsation or thrill (44%), hemorrhage (27%), congestive heart failure (18%), and symptoms due to mass effect (35%). A significant number of patients had undergone previous, unsuccessful attempted surgical treatment of the lesion (32%). The most common type of lesion noted on arteriography was arteriovenous shunting (89%). Patients required a mean of 2.4 embolization procedures (range, 1-11 procedures) over a mean period of 23.3 months (range, 1-144 months). The most common agents used were rapidly polymerizing acrylic adhesives. The most common vessels involved and treated were branches of the hypogastric artery (82%). More than one procedure were performed in 20 patients (53%). Seven were planned as staged embolizations, whereas 13 were due to residual or recurrent symptoms. Adjunctive surgical procedures were performed subsequent to embolization therapy in five patients (15%). Eighty-three percent of patients were asymptomatic or significantly improved at a mean follow-up of 84 months (range, 1-204 months). CONCLUSIONS: Pelvic vascular malformations are difficult to eradicate completely, and recurrences are common. Many patients require multiple therapeutic interventions. However, most of these difficult cases have good results in the long term. Transcatheter embolization plays a significant role in, and may be the treatment of choice for, symptomatic pelvic vascular malformations.     

An outpatient anticoagulation protocol managed by a vascular nurse-clinician

Lifetime anticoagulation has become a therapeutic option for surgical patients with hypercoagulable states or prosthetic arterial bypass grafts. However, physicians may not achieve optimal anticoagulation or may attempt to limit the length of the therapy period because of the perceived morbidity from hemorrhagic complications of Coumadin therapy. A protocol for anticoagulant therapy monitored and regulated by a vascular nurse-clinician was reviewed. Coumadin was prescribed for 1,891 patient-months to 93 patients to maintain their prothrombin time 1.5 to 2 times control (range: 18 to 24 seconds). The mean (+/- SD) prothrombin time for the study population was 19.8 +/- 1.8 seconds. During follow-up, 472 (14%) of 3,479 prothrombin times measured were below the therapeutic range (n = 232) or prolonged (n = 240), prompting an adjustment in the Coumadin dose in 82 (88%) patients. Four patients developed recurrent vascular graft thrombosis while receiving anticoagulation. There were 6 major and 11 minor hemorrhagic complications. Patients with a chronic risk for arterial or venous thrombosis can have out-patient anticoagulant therapy administered at optimal intensity and regulated safely with a low incidence of hemorrhagic and thrombotic events.     

多普勒超声技术动态观察血管性勃起功能障碍患者阴茎血流动力学的变化

目的动态观察多普勒超声技术配合阴茎海绵体注射在血管性勃起功能障碍患者诊断中的价值。方法120例疑血管性ED患者在阴茎注射PGE1后5min、10min和20min应用多普勒超声技术测量阴茎血流动力学变化,指标包括:收缩期峰值流速(PSV)、舒张末期峰值流速(EDV)、血流阻力指数(RI)。另100例心因性ED设为对照组。第一次注射后勃起不佳的患者3d后增加PGE1剂量重新检测。结果120例患者可以观察到明显的血流动力学变化,其中有动脉性ED者34例,静脉性ED 55例,混合血管性31例。ICI后不同时间的多普勒测量其血流动力学变化有一定差异。结论多普勒超声技术诊断血管性勃起功能障碍有一定意义。阴茎海绵体注射药物后须动态观察阴茎血流动力学的变化。     

Vascular complications of intra-aortic balloon insertion in patients undergoing coronary reavscularization: analysis of 911 cases.

OBJECTIVE: Intra-aortic balloon pump (IABP) is a well-accepted and widely used mechanical circulatory support in cardiac surgical practice. We evaluated the vascular complications of IABP and risk factors associated with the development of these complications in patients undergoing myocardial revascularization. METHODS: Between January 1994 and December 2000, a total of 911 patients undergoing coronary artery bypass grafting received IABP. The preoperative risk factors, balloon-related variables and vascular complications were studied and analyzed. Univariate and multivariate analyses were performed to identify risk factors for the development of vascular complications. RESULTS: Mean age of the patients was 59.2+/-9.1 years and 10.5% of the patients were female. The incidence of diabetes and peripheral vascular disease was 41.1 and 8.5%, respectively. The mean Parsonnet score was 11.8+/-4.6. IABP was inserted by percutaneous technique in 96.8% of patients. The duration of IABP therapy ranged from 20 h to 21 days (mean 3.8 days). Fifty-four (5.9%) patients developed major and 53 (5.8%) patients developed minor vascular complications. Ischaemia of the limb, requiring thromboembolectomy, developed in 25 (2.7%) patients. Patients who received IABP preoperatively had higher incidence of major vascular complications as compared to patients who received IABP in operating room before induction of anaesthesia. Multiple logistic regression analysis revealed age, triple vessel disease, indications of IABP therapy (unstable angina, cardiac arrhythmia and haemodynamic instability), left ventricular aneurysm surgery and use of balloon with sheath as independent risk factors for the development of vascular complications. CONCLUSIONS: IABP therapy is associated with certain vascular complications, which should always be kept in mind before insertion of a balloon. The use of a balloon without sheath and proper evaluation of peripheral circulation can help to minimize the development of vascular complications.     

Effects of midazolam on the coronary circulation in patients with coronary artery disease

The effects of midazolam on coronary sinus blood flow (CSBF), myocardial oxygen consumption (MVO2), and myocardial lactate balance were investigated in eight patients with stable coronary artery disease undergoing cardiac catheterization. Coronary sinus blood flow was measured by continuous thermodilution. Arterial and coronary sinus blood were analyzed for oxygen and lactate content. The determinants of left ventricular (LV) performance were obtained from the cardiac output measured by thermodilution and from left heart catheterization data. All data were obtained before, and 5 and 15 min after midazolam, 0.2 mg X kg-1 iv. Sleep was induced in all patients after administration of midazolam and persisted throughout the entire study period. Mean aortic and LV end-diastolic pressure were decreased from control values (-15 and -44%, respectively), as well as cardiac index and stroke index (-10 and -15%, respectively). Heart rate increased moderately (+8%), while no change in systemic vascular resistance and maximum velocity of shortening (Vmax) were observed. Midazolam administration was followed by a decrease of CSBF (-24%) and of MVO2 (-26%). Coronary vascular resistance did not change, but coronary sinus oxygen tension increased slightly, suggesting a mild alteration in normal autoregulation. However, no evidence of myocardial ischemia occurred, as judged by the absence of changes in the: 1) ECG, 2) myocardial lactate extraction, and 3) relaxation time constant. These results suggest that midazolam may be used safely in patients with coronary artery disease.     

Resumption of spontaneous erections in selected patients affected by erectile dysfunction and various degrees of carotid wall alteration: role of tadalafil

OBJECTIVE: To evaluate the possible improvement of sexual activity following a non on-demand administration of a long half-life selective inhibitor of phosphodiesterase type 5 (PDE-5) in elderly patients without major cardiovascular risk factors. METHODS: Sixty subjects with erectile dysfunction (ED) aged 60-70 years and 30 control patients aged 18-40 years, affected by psychogenic ED, were studied. All underwent routine and hormonal blood tests, Nocturnal Penile Tumescence Rigidity Monitoring test (NPTRM), ultrasonographyc evaluation of common carotid artery intima-media thickness (IMT) and penile colour Doppler ultrasonography (P-CDU). All patients underwent therapy with tadalafil 20 mg in alternative days, non on-demand, at 5.00 p.m., for three consecutive months. IIEF-5, NPTRM test and P-CDU were re-evaluated one month after the end of the therapy. RESULTS: Among elderly subjects 20 (33%) had normal carotid IMT (< 0.9 mm), 15 (25%) minimal increase of carotid thickness (IMT = 0.9-1.2 mm) and 25 (42%) one or more carotid plaques (IMT > 1.3 mm). NPTRM and P-CDU parameters were inversely related to different degrees of carotid wall alteration and showed a significant improvement respect to pre-treatment only in patients without atherosclerotic plaques. Also IIEF-5 showed significant improvements only in patients without atherosclerotic plaques. CONCLUSIONS: In elderly subjects with slight or no signs of vascular disease at the carotid level, chronic and non on-demand treatment with tadalafil can induce spontaneous resumption of erections, probably through the improvement of endothelial function, but direct evidences to confirm this hypothesis are required.     

Formalized radiology rounds: the final component of the tertiary survey

BACKGROUND: An important objective of organized trauma care is to minimize delayed diagnoses and missed injuries. Discrepant interpretations of radiographs initially read by trauma surgeons represent a unique source of delayed diagnoses. The purpose of this study was to evaluate the efficacy of formalized radiology rounds as a component of the tertiary survey. METHODS: Over an 18-month period, 432 consecutive patients admitted to the trauma service at a Level II trauma center were studied prospectively. Radiographs obtained as part of the initial evaluation were initially interpreted by an attending trauma surgeon. All radiographs from the previous 24-hour admissions were reviewed by the trauma team with an attending radiologist at radiology rounds. New diagnoses (NDx) were defined as radiographic findings identified at radiology rounds that were not recorded by the trauma surgeon at the time of initial evaluation. The clinical significance of any NDx was described as follows: level 1, NDx resulted in significant morbidity/mortality; level 2, NDx resulted in alteration in care/no morbidity; level 3, NDx resulted in no alteration in care; level 4, NDx was an incidental finding by the radiologist; level 5, NDx by radiologist not definite. RESULTS: Forty-seven NDx were identified in 42 patients (9.7%). Of the 47 NDx, 19 (40.4%) were level 3 and 28 (59.6%) were level 2. No level 1 NDx were identified. Forty-four changes in clinical management were documented in the level 2 group. Eight new consults were ordered in seven patients (16.7%): orthopedic surgery (n = 6), neurosurgery (n = 1), and physical therapy (n = 1). Seventeen additional diagnostic procedures were required in 16 patients (38.1%): plain radiographs (n = 11) and computed tomographic scans (n = 6). Nineteen therapeutic changes were required in 16 patients (38.1%): splint/immobilization device (n = 7), modified level of activity (n = 6), surgical procedures (n = 4), transfer (n = 1), and home equipment (n = 1). CONCLUSION: A small number of radiographic findings are not detected by trauma surgeons during the initial evaluation. Although these findings are not of major clinical significance, the majority required some alteration in care plan. Formalized radiology rounds promotes clinical efficiency through early identification of these injuries, which facilitates any necessary alteration in the care plan.     

EEG power changes are more sensitive than spectral edge frequency variation for detection of cerebral ischemia during carotid artery surgery: a prospective assessment of processed EEG monitoring.

To investigate the basis of ambiguous reports of the validity and utility of processed electroencephalogram (EEG) detection of cerebral ischemia, 19 patients monitored during surgical procedures requiring clamping of the carotid artery were studied. The EEG was recorded and observed for detection of alteration of spectral edge frequency versus EEG power. Electrodes were positioned at the P3-C3' locations over the left hemisphere and P4-C4' areas over the right hemisphere (10-20 system of electrode placement). Maximum sensitivity was used for recordings of the processed EEG. Twelve of 19 patients had bilateral carotid vascular stenosis. Nine of 19 patients studied with EEG monitoring had EEG changes suggestive of cerebral ischemia during interruption of carotid artery blood flow by surgical manipulation, defined as a decline in EEG power of greater than 40% or a decline in spectral edge frequency of at least 3 Hz. Eight of these episodes occurred at the time of carotid vascular clamp placement. These changes were confirmed by the raw EEG. Whereas power band monitoring detected 9 episodes of suspected ischemia, alteration of spectral edge frequency was sufficient to detect only 2 of these episodes. One patient sustained a right hemispheric stroke detected intraoperatively by a 47% decline in EEG power; however, these changes were unaccompanied by intraoperative alteration of spectral edge frequency. It is concluded that monitoring of EEG power with processed EEG devices is a more sensitive indicator of cerebral ischemia than monitoring only the spectral edge frequency of the EEG.