选择性吲哚氰绿荧光显影技术在颅颈交界区硬膜动静脉瘘手术中的作用

目的探讨应用选择性吲哚氰绿荧光显影技术在颅颈交界区硬膜动静脉瘘手术中的作用。方法回顾性分析2014年6月至2017年1月首都医科大学宣武医院治疗的24例(26侧)颅颈交界区硬膜动静脉瘘患者的临床资料,其中15例表现为蛛网膜下腔出血,8例为静脉高压性脊髓损伤症状,1例为延髓受压症状。术中应用选择性吲哚氰绿荧光显影技术,即暂时夹闭动脉化引流静脉的起始部,在吲哚氰绿荧光显影动脉期后开放引流静脉,从而判定动静脉瘘口位置。术后复查DSA,并以改良Rankin量表(mRS)评价临床疗效。结果 24例患者26侧的硬膜动静脉瘘均经术中瘘口离断,术中吲哚氰绿荧光显影及术后DSA随访证实瘘口均离断。术后随访时间4~30个月,21例患者mRs评分0~1分,2例Hunt-HessⅢ级蛛网膜下腔出血mRs评分2分,1例术前脑干受压症状患者mRs评分3分。结论选择性吲哚氰绿荧光显影技术是手术治疗颅颈交界区硬膜动静脉瘘寻找瘘口的一项安全、简便、有效的技术。     

岩上静脉引流的硬脑膜动静脉瘘诊治分析

目的探讨岩上静脉引流的硬脑膜动静脉瘘的临床表现、影像学特点及治疗方式。方法回顾性连续纳入2013年5月至2014年9月首都医科大学宣武医院神经外科和北京海淀医院神经外科由岩上静脉引流的硬脑膜动静脉瘘患者9例,采用血管内栓塞或显微外科手术治疗,并于手术前后完善MRI、DSA检查,进行改良AminoffLogue量表(ALS)评分。结果 9例患者中6例为男性,3例为女性,均表现不同程度的肢体感觉及运动异常,其中7例伴有排尿和(或)排便障碍,4例患者伴有颅神经功能异常,包括声音嘶哑、饮水呛咳、呃逆、面瘫等;6例接受栓塞治疗,3例接受外科手术,均达到解剖学治愈。术前ALS评分为(6.0±2.7)分,术后3个月为(2.8±1.7)分,治疗前后差异有统计学意义(t=4.816,P0.05)。结论岩上静脉引流的硬脑膜动静脉瘘是一类较为少见的脑血管畸形,病变累及范围广泛,临床表现严重,血管内栓塞治疗和显微外科手术均能获得较为理想的疗效,若血管条件允许,应首选介入栓塞治疗。     

静脉窦内球囊保护下Onyx栓塞侧窦区硬脑膜动静脉瘘的随访分析

目的初步探讨侧窦区硬脑膜动静脉瘘的栓塞治疗中,静脉窦内球囊保护技术的疗效及安全性。方法回顾性连续纳入2012年12月至2016年8月,经静脉窦内球囊保护下,使用Onyx栓塞侧窦区硬脑膜动静脉瘘7例患者,并对其临床资料、影像学资料及随访结果进行分析。结果 7例患者中,瘘口位于乙状窦区3例、横窦区4例。术后即刻造影显示完全栓塞5例,大部分栓塞2例,球囊保护静脉窦均保持通畅。临床随访7例,随访时间为术后6~43个月,无新发神经功能缺损。7例患者均获全脑DSA复查,随访时间为术后6~11个月,提示5例完全治愈,其中4例静脉窦通畅,1例闭塞;1例瘘口稳定且静脉窦通畅,1例瘘口新发合并静脉窦闭塞。结论静脉窦内球囊保护下栓塞硬脑膜动静脉瘘在栓塞瘘口的同时,可长期维持静脉窦通畅,有利于维持栓塞效果的稳定性。     

静脉高压性脑干水肿的诊断与治疗

目的探讨以静脉高压性脑干水肿起病的硬脑(脊)膜动静脉瘘的临床表现及诊疗策略。方法回顾分析2014-08～2015-08就诊于首都医科大学宣武医院神经外科的5例表现为静脉高压性脑干病变的硬脑(脊)膜动静脉瘘患者资料,包括病史、影像学、治疗情况和随访资料。结果 5例患者病因包括2例岩上窦区硬脑膜动静脉瘘(DAVF),1例舌下神经管区DAVF,1例颅颈交界区DAVF,1例颈段硬脊膜动静脉瘘(SDAVF)。经栓塞治疗1例,显微外科手术4例。术后均经数字减影血管造影(DSA)复查明确瘘口消失,磁共振成像(MRI)复查可见脑干水肿缓解,患者症状体征均得到不同程度改善。结论静脉高压性脑干水肿病变严重,由硬脑(脊)膜动静脉瘘引起,临床症状并无特异性,MRI及DSA检查具有诊断价值。     

复杂硬脑膜动静脉瘘的静脉途径栓塞治疗

目的探讨静脉途径栓塞治疗复杂性硬脑膜动静脉瘘的有效性和安全性。方法回顾分析6例复杂性硬脑膜动静脉瘘患者行经静脉途径栓塞治疗的临床效果。结果静脉途径栓塞治疗后,5例患者解剖性治愈(造瘘口消失),另1例患者症状好转。1例患者乙状窦栓塞后吞咽困难,1例患者海绵窦栓塞后外展不佳,经对症治疗均好转。结论静脉途径栓塞是治疗复杂性硬脑膜动静脉瘘较好的方法。     

经静脉入路采用Onyx或联合弹簧圈治疗海绵窦区硬脑膜动静脉瘘的疗效

目的探讨经静脉入路采用Onyx或联合可脱性弹簧圈栓塞治疗海绵窦区硬脑膜动静脉瘘的安全性和有效性。方法回顾性分析2007年2月—2010年12月,经静脉入路栓塞治疗的12例海绵窦区硬脑膜动静脉瘘患者的临床资料,其中经岩下窦入路10例,经面静脉-眼上静脉入路2例。单独应用Onyx 8例,Onyx联合可脱性弹簧圈4例。结果①治疗后即刻血管造影显示完全闭塞10例,少量残留2例。单独应用Onyx栓塞治愈6例,好转2例,Onyx联合可脱性弹簧圈栓塞治愈2例,好转2例;总有效率100%,治愈率66.7%,无加重或死亡病例。②2例术中出现心动过缓,3例术后出现眶部疼痛。③对所有患者进行临床随访,随访时间为6～32个月,无复发及加重者。结论静脉入路Onyx或联合可脱性弹簧圈栓塞海绵窦区硬脑膜动静脉瘘的疗效确实,安全可靠。     

多静脉途径Onyx胶介入栓塞海绵窦区硬脑膜动静脉瘘的疗效观察

目的观察多种静脉途径Onyx胶介入栓塞海绵窦区硬脑膜动静脉瘘的临床疗效。方法选取21例栓塞海绵窦区硬脑膜动静脉瘘病人,分别采用经股静脉-岩下窦联合Onyx胶栓塞治疗、经面静脉-眼上静脉结合Onyx胶栓塞治疗。结果 21例病人共行栓塞治疗26侧,21侧采用经股静脉-岩下窦介入栓塞治疗,5侧采用经面静脉-眼上静脉栓塞治疗;治疗后磁共振血管造影显示,23侧完全闭塞,瘘口完全消失,有3侧虽然海绵窦填塞完整,但1侧出现少量岩下窦引流,2侧出现少量翼丛引流,在压颈2个月后消失;经静脉途径Onyx胶栓塞治疗后16例病人完全治愈,治愈率90.47%;治疗后3例病人出现头痛伴有呕吐,采用西药治疗后症状明显缓解,1例病人治疗后出现外展神经麻痹,6个月后症状自行消失,无严重并发症发生;随访3个月~27个月无复发情况。结论多静脉途径Onyx胶介入栓塞海绵窦区硬脑膜动静脉瘘的疗效显著,可作为临床首选治疗方式。     

经未显影静脉窦栓塞治疗硬脑膜动静脉瘘

目的探讨经未显影静脉窦栓塞治疗硬脑膜动静脉瘘（DAVF）的可行性、安全性及有效性。方法回顾性分析92例经未显影静脉窦栓塞治疗的DAVF患者的临床资料，其中病变位于海绵窦区91例，侧窦区1例。经颈内静脉的起始段探查未显影岩下窦，进入引流静脉窦内栓塞海绵窦区DAVF；通过颈内静脉探查未显影乙状窦，进入静脉窦栓塞侧窦区DAVF。首选可控纤毛弹簧圈进行栓塞，待血流减慢以后，用游离纤毛弹簧圈继续栓塞。若仍存在少量瘘口，通过静脉窦内注射液体栓塞剂（25％～33％Glubran或Onyx18），观察置管的成功率、安全性和栓塞的疗效。术后6个月通过电话、门诊或DSA随访。结果92例患者中，均未出现并发症，无死亡病例。1例海绵窦区DAVF患者置管失败；其余91例患者均顺利置管，并成功进行静脉栓塞。所有患者栓塞后即刻造影，均未见异常静脉窦早显，瘘口消失，达到了影像学上治愈。置管成功率及治愈率均为99％（91／92）。术后6个月对38例进行随访，无一例DAVF复发。对其余患者进行电话或门诊随访。所有患者临床症状好转或消失。结论经未显影静脉窦栓塞治疗DAVF，尤其对于海绵窦区DAVF，经未显影岩下窦超选择置管进行栓塞，具有较高的可行性、安全性及有效性，可作为海绵窦区DAVF的首选常规治疗方法。     

吲哚菁绿血管造影在脑血管畸形手术中的作用

目的 探讨吲哚菁绿（ICG）血管造影在脑血管畸形手术中的作用。方法 回顾性分析2007年6月至2008年5月，南京军区南京总医院神经外科手术治疗的5例脑血管畸形患者。术中应用ICG显示畸形血管、供血动脉和引流静脉，评价术中ICG造影在手术中的作用。结果 本组5例脑血管畸形患者，其中脑动静脉畸形2例，硬脑膜动静脉瘘3例。5例患者均接受了脑血管畸形切除术。2例脑动静脉畸形手术中在切除畸形团前进行了术中ICG血管造影，清晰显示出畸形团、供血动脉和引流静脉；3例硬脑膜动静脉瘘手术中应用ICG造影确定了瘘口的位置，成功地阻断瘘口。患者术后复查DSA，证实畸形血管均被完全切除，正常血管得到保留。结论 术中ICG血管造影能够帮助术者明确脑血管畸形的状况，指导手术治疗脑血管畸形。研究支持在脑血管畸形手术中常规应用ICG脑血管造影。     

术中影像导航下切除脊髓圆锥处脊髓动静脉瘘

日本的学者们进行了直接手术切除脊髓圆锥动静脉瘘（AVF）的研究。报道了2例由脊髓前动脉供血的脊髓圆锥动静脉瘘,经术中影像导航（如DSA、动脉内染料注射或吲哚青绿荧光造影）成功进行了手术闭塞瘘口。治疗脊髓AVF的关键是完全闭塞瘘口,同时保证脊髓的正常血供。术中必须首先安全分离供血动脉、血管巢和引流静脉,然后通过术中影像导航,明确瘘口的血流和解剖定位。第1例患者在也脊髓节段有血管巢,由脊髓前动脉通过左L1节段性动脉供血。第2例患者的血管巢位于IA／5脊髓水平,由脊髓前动脉通过左T11肋间动脉供血。     

岩下窦入路栓塞治疗原发性眼眶静脉曲张

目的探讨经静脉途径栓塞治疗原发性眼眶静脉曲张有效性。方法回顾性分析2007年1月至2015年1月12例原发性眼眶静脉曲张患者的临床资料,均经岩下窦置入微导管,以微弹簧圈、Onyx18胶栓塞原发性眼眶静脉曲张。4例行单纯微弹簧圈栓塞,3例行Onyx胶栓塞,5例行微弹簧圈+Onyx胶栓塞。结果成功导管到位后,对12例患者完全栓塞病灶。患者体位性眼球突出症状消失、疼痛缓解,10例患者症状明显好转,2例患者部分缓解(单一材料栓塞)。9例患者随访6~24个月,行眶DSA、MRI或CT复查,眶曲张静脉病灶内血栓形成,并且未见空腔,9例DSA随访患者未见复发,其中1例患者患侧眼球外展受限。另3例失访。结论经岩下窦途径栓塞治疗原发性眼眶静脉曲张安全、有效、便捷。     

Remission with Cabergoline in Adolescent Boys with Cushing’s Disease

Cabergoline is a long-acting dopamine receptor agonist used for treatment of patients with uncured Cushing’s disease (CD) and, as a first-line treatment, was used in only limited numbers of patients. This report presents two adolescent boys with CD who were treated with cabergoline. Two adolescent boys with clinical and laboratory findings of CD are presented. No pituitary adenoma was detected by radiological investigation in either patient. Adrenocorticotropic hormone (ACTH) hypersecretion and lateralization was found by inferior petrosal sinus sampling in both patients. The initial cabergoline dose was 1mg/week and was adjusted up to 1.5 mg/week in the second patient, based on his urinary free cortisol (UFC) level. The patients responded to cabergoline treatment with normal UFC levels on the 4th and 6th months of treatment. The boys reached complete remission at the end of the 17th and 24th months, respectively. Cabergoline is effective in the control of cortisol secretion and can be considered as a first-line treatment in cases of CD. Conflict of interest:None declared.     

Multihormonal bilateral petrosal sinus sampling in Cushing's disease: radiological, surgical and pathological correlations

Multihormonal bilateral petrosal sinus sampling (BPSS) has been proposed to improve corticotroph microadenomas prediction of lateralisation. Few series have simultaneously compared data of pituitary MRI, surgical findings and multihormonal BPSS. Seven patients (6F/1M) with Cushing's disease, mean age at diagnosis of 35 years (range 24-55) were prospectively studied to compare radiological and multihormonal BPSS data with surgical and pathological findings. In untreated patients, simultaneous measures of ACTH, TSH and prolactine (PRL) were done at time 0, 7, 15, 22 minutes after CRH (500 microgram) and TRH (200 microgram) stimulation. An intersinus gradient of 1.4 was considered as a lateralisation. All microadenomas were identified during surgery, diameters ranged from 2 to 7 mm. All patients were in long-term surgical remission. Pathological studies confirmed a tumoral tissue with ACTH immunostaining in 6/7 cases and PRL in 3/7 cases. Pituitary MRI correctly identified tumors in 4 cases, the remaining tumors were not seen. Basal and stimulated intersinus gradients of ACTH, TSH and PRL were homolateral in 6/7 cases and were coincident with surgical findings in 4/7 cases. The other three cases were contralateral to MRI and surgical data. In conclusion, simultaneous gradient of ACTH, PRL and TSH did not improve lateralisation prediction in this series. Hormonal hypersecretion was homolateral in six cases whereas pathological studies demonstrated a mixed secretion in only three cases. A preferential pituitary draining could explain these discordances. Data from our series and from others (done with CRH stimulation and ACTH-PRL measures) strongly suggest a paracrine interaction between tumoral and normal pituitary tissue.     

The role of bilateral inferior petrosal sinus sampling in the diagnosis of Cushing's syndrome

Adrenocorticotropin hormone (ACTH)-dependent Cushing's syndrome is most often due to a pituitary corticotroph adenoma, with ectopic ACTH-secreting tumors representing approximately 15% of cases. Biochemical and radiological techniques have been established to help distinguish between these two entities, and thus aid in the localization of the neoplastic lesion for surgical resection. The test that offers the highest sensitivity and specificity is bilateral inferior petrosal sinus sampling (BIPSS). BIPSS is an interventional radiology procedure in which ACTH levels obtained from venous drainage very near the pituitary gland are compared to peripheral blood levels before and after corticotropin hormone (CRH) stimulation. A gradient between these two locations indicates pituitary Cushing's, whereas the absence of a gradient suggests ectopic Cushing's. Accurate BIPSS results require hypercortisolemia to suppress normal corticotroph ACTH production and hypercortisolemia at the time of the BIPSS to assure excessive ACTH secretion. In some cases, intrapituitary gradients from side-to-side can be helpful to localize small corticotroph adenomas within the sella. BIPSS has rare complications and is considered safe when performed at centers with experience in this specialized technique.     

INFERIOR PETROSAL SINUS SAMPLING IN ACROMEGALY

In view of the diagnostic value of bilateral simultaneous inferior petrosal sinus sampling (BSIPSS) in localising preoperatively the site of the microadenoma in pituitary dependent Cushing s disease, the clinical value of BSIPSS was evaluated in five acromegalic patients with equivocal or negative pituitary CT scans. Intersinus GH gradients were obtained for all patients (range 1.6–4.2) but in only one case was the gradient correctly localised to the side of the tumour. Gradients of several other pituitary hormones, particularly prolactin (range 1.6–4.0), also demonstrated gradients parallel to the GH intersinus gradients. Despite the paradoxical intersinus GH gradients, the surgeon was able to readily identify the tumour at the time of surgery. Thus BSIPSS is of little assistance to the surgeon for the preoperative radiological evaluation in acromegaly and these results caution against the universal adoption of the BSIPSS technique in the radiological assessment of all secretory pituitary microadenomas.     

Routine inferior petrosal sinus sampling in the differential diagnosis of adrenocorticotropin (ACTH)-dependent Cushing's syndrome: early recognition of the occult ectopic ACTH syndrome.

The clinical, biochemical, and radiographic features of ectopic ACTH-dependent Cushing's syndrome are often indistinguishable from those of pituitary ACTH-dependent hypercortisolism (Cushing's disease). We prospectively evaluated 29 patients with ACTH-dependent hypercortisolism by means of bilateral inferior petrosal sinus ACTH sampling with ovine CRH (oCRH) stimulation. Patients with Cushing's disease (n = 20), had a maximal basal inferior petrosal sinus to peripheral ACTH ratio (IPS:P-ACTH) of 11.7 +/- 4.4 (+/- SE) from the dominant IPS, which increased to 50.8 +/- 18.3 after oCRH administration. Bilateral IPS sampling was necessary to correctly identify patients with Cushing's disease, since the maximal basal nondominant IPS:P-ACTH was less than 2.0 in over 50% of the patients and remained less than 2.0 after oCRH administration in one third. In contrast, patients with occult ectopic ACTH-secreting neoplasms (n = 9) had maximal basal IPS:P-ACTH of 1.2 +/- 0.1 that did not change after oCRH administration. Occult ectopic ACTH-secreting neoplasms were found in 7 of 9 patients from 0.4-14 yr after the recognition of Cushing's syndrome, and 4 of these patients had intermittent hypercortisolism with prolonged periods of remission. Selective endobronchial lavage for ACTH correctly localized a radiologically occult ACTH-secreting bronchial carcinoid in 1 patient, and magnetic resonance imaging identified a similar neoplasm in a patient with a normal chest computed tomographic scan. Basal ACTH and urinary free cortisol excretion were significantly higher in patients with ectopic ACTH than in those with Cushing's disease, but overlap existed between groups. High dose dexamethasone suppression testing inaccurately classified 24% of patients, and radiological imaging of the pituitary and adrenal glands was misleading. The occult ectopic ACTH syndrome is a common form of ACTH-dependent hypercortisolism that cannot be distinguished from Cushing's disease with routine clinical studies. The accurate differential diagnosis of ACTH-dependent Cushing's syndrome requires bilateral inferior petrosal sinus ACTH sampling with oCRH stimulation.     

Pituitary tumour localization in patients with Cushing's disease by magnetic resonance imaging. Is there a place for petrosal sinus sampling?

OBJECTIVE We wished to analyse the relative value and diagnostic accuracy of bilateral simultaneous inferior petrosal sinus blood sampling for plasma ACTH measurements when compared with pituitary magnetic resonance imaging (MRI) for the preoperative localization of microadenoma (tumour diameter <10 mm) within the pituitary fossa in patients with Cushing's disease. DESIGN Pituitary MRIs were assessed blind and independently. The sinus blood sampling was performed before and after administration of corticotrophin releasing hormone (CRH). The ratios of the ACTH concentrations in plasma samples from the inferior petrosal sinuses to the concentrations in peripheral blood plasma samples (the IPS:P ratio) and the ratios of the ACTH concentrations in samples from both inferior petrosal sinuses (the inter-sinus gradient) were calculated. PATIENTS Twenty consecutive patients with Cushing's disease were prospectively studied. All but two patients subsequently underwent transsphenoidal exploration of the pituitary fossa. RESULTS In three of 20 patients (15%), positioning of catheter tips in both inferior petrosal sinuses was unsuccessful. The diagnosis of Cushing's disease was confirmed by the greater basal IPS: P ratio amounting to 3; 2 0 in 13 of 17 patients (76%), and amounting to > 3 0 in CRH-stimulated peak samples in 15 of 17 patients (88%). Anatomical variations of the inferior petrosal sinus, precluding reliable conclusions about lateralization of pituitary venous ACTH drainage, were observed in five of 20 patients (25%). Adding the three patients with technical failure and one patient who presented with a macroadenoma (tumour diameter 11 mm), this left interpretable data with regard to lateralization of the microadenomas in only 11 of 20 patients (55%). In 15 of 20 patients (75%) a pituitary microadenoma was found at MRI. In 14 of these 15 patients (93%) a tumour was indeed found at that position at subsequent transsphenoidal operation. Concordance between the lateralization by the intersinus gradient and microadenoma localization by MRI was observed in six of 11 cases (55%) when using basal samples and in seven of 11 cases (64%) when using peak samples obtained after stimulation with CRH. Concordance between the lateralization by the intersinus gradient and subsequent microadenoma localization at surgery was observed in seven of 11 patients (64%) before and in eight of 11 cases (73%) after CRH stimulation. Reversal of the intersinus gradient after CRH stimulation, suggesting a shift in the lateralization to the contralateral side of the gland, was found in three of 12 cases (25%). CONCLUSIONS Bilateral simultaneous inferior petrosal sinus blood sampling for plasma ACTH measurements before and after CRH stimulation successfully confirmed the diagnosis of pituitary dependent Cushing's disease in 15 of 17 patients (88%) in whom this diagnosis was suspected on the basis of conventional biochemical testing. Magnetic resonance imaging, however, is superior to bilateral simultaneous inferior petrosal sinus blood sampling for the localization/lateralization of pituitary microadenomas in patients with Cushing's disease. Therefore, bilateral simultaneous inferior petrosal sinus blood sampling should be reserved for the assessment of those patients with Cushing's syndrome in whom either the results of biochemical tests are equivocal and/or subsequent pituitary magnetic resonance imaging gives unconvincing results.     

Internal jugular vein sampling in adrenocorticotropic hormone-dependent Cushing's syndrome: a comparison with inferior petrosal sinus sampling

OBJECTIVE: Distinguishing between pituitary-dependent Cushing's syndrome (CS) and occult ectopic ACTH syndrome can be extremely difficult. Bilateral inferior petrosal sinus sampling has been shown to have the highest diagnostic accuracy in this subtype evaluation. Internal jugular vein sampling (IJVS) has been reported as a potentially safer invasive alternative, but data are limited. Our objective was to compare the sensitivity and specificity of bilateral IJVS and bilateral inferior petrosal sinus sampling (IPSS) in patients with ACTH-dependent CS. DESIGN: We prospectively collected blood samples from the inferior petrosal sinus and internal jugular vein of consecutive patients with ACTH-dependent CS. PATIENTS: The study group included 35 patients: 32 with pituitary-dependent CS (positive immunohistochemical findings for ACTH pituitary tumour or biochemical cure after pituitary surgery) and three with histologically proven ectopic ACTH syndrome. MEASUREMENTS: Inferior petrosal sinus sampling and bilateral IJVS were performed simultaneously before and after administration of corticotropin-releasing hormone (CRH), and ratios of central-to-peripheral ACTH concentrations were calculated. RESULTS: The basal IJVS central-to-peripheral ACTH ratios were diagnostic for pituitary-dependent CS (> 2) in 15 patients (46.9%), as were basal inferior petrosal sinus sampling central-to-peripheral ACTH ratios in 29 patients (90.6%). The post-CRH IJVS central-to-peripheral ACTH ratios were diagnostic for pituitary-dependent disease (> 3) in 24 patients (75%), as were post-CRH inferior petrosal sinus sampling central-to-peripheral ACTH ratios in 28 patients (87.5%). In the three patients with ectopic ACTH CS, the IJVS and inferior petrosal sinus sampling pre- and post-CRH ACTH ratios were correctly negative. The overall sensitivity of combined pre- or post-CRH was 81.3% for IJVS and 93.8% for inferior petrosal sinus sampling. Because of the difference between mean ratios in the two techniques, new criteria for IJVS were mathematically calculated: a pre-CRH central-to-peripheral ACTH ratio of 1.59 and a post-CRH central-to-peripheral ACTH ratio of 2.47 maximized sensitivity and specificity when both of these are equally taken into consideration. CONCLUSION: In conclusion, IJVS is not superior to inferior petrosal sinus sampling for establishing the cause of ACTH-dependent CS. When new criteria of basal (> 1.6) and post-CRH (> 2.5) central-to-peripheral ACTH gradients were applied to ACTH ratios from IJVS, the sensitivity of this test was maximized. However, confirmatory inferior petrosal sinus sampling is recommended when there is a lack of a central-to-peripheral ACTH gradient and when there is only a gradient above the cut-off on basal (pre-CRH) sampling.