Correlation of older age with better progression-free survival despite less aggressive resection in nonfunctioning pituitary adenomas.

OBJECTIVE: Nonfunctioning pituitary adenomas (NFPAs) present at a wide range of ages; it is possible that variable outcomes are based on patient age at presentation. This study aimed to explore long-term outcomes of patients with NFPAs following endonasal transsphenoidal surgery (ETS), considering age stratification. METHODS: This retrospective study included 228 patients with NFPAs who underwent ETS, with a median follow-up period of 63 months. The outcomes included progression-free survival (PFS) rates and neurological and endocrinological outcomes. Age-stratified Kaplan-Meier and Cox proportional hazards analyses were performed. Patients were classified into four age groups: ≤ 49, 50-59, 60-69, and ≥ 70 years. RESULTS: Age-stratified analysis showed a significant correlation between age and PFS in NFPAs (5-year PFS rates: 63.0% in those ≤ 49 years, 76.7% in those 50-59 years, 85.0% in those 60-69 years, and 88.1% in those ≥ 70 years; p = 0.001, log-rank test). Bivariate (HR 1.03, 95% CI 1.01-1.05; p = 0.001) and multivariable (HR 1.03, 95% CI 1.02-1.05; p = 0.001) analyses demonstrated that older age was significantly associated with longer PFS. Multivariable analysis also demonstrated that smaller maximum tumor diameter (HR 0.77, 95% CI 0.60-0.99; p = 0.036) and gross-total resection (HR 8.55, 95% CI 3.90-18.75; p = 0.001) were significantly associated with longer PFS. Multivariable logistic regression analysis demonstrated that only younger age was associated with postoperative improvement of male hypogonadism (HR 0.91, 95% CI 0.84-0.99; p = 0.019). Other postoperative neurological and endocrinological outcomes were not significantly associated with age. CONCLUSIONS: Older patients with NFPAs treated with ETS demonstrated a longer PFS. Of endocrinological outcomes studied, only male hypogonadism improvement was associated with younger patient age.

Angiographic cross-filling between inferior petrosal sinuses and alteration of adrenocorticotropic hormone sampling results for tumor localization in Cushing disease.

OBJECTIVE: Inferior petrosal sinus (IPS) sampling (IPSS) is a diagnostic procedure used to guide diagnostic localization of imaging-negative adrenocorticotropic hormone (ACTH)-secreting pituitary microadenomas. However, the efficacy of IPSS has been suboptimal at accurately lateralizing the adenoma, reducing surgical cure rates and leading to unintended pituitary dysfunction due to the added exploration. One rationale for the occasional imprecision is the existence of additional petrosal sinus collateral channels that connect the IPS bilaterally, which may lead to false localization results during sampling. The aim of this study was to explore a potential connection between normal anatomical variation in the angioarchitecture of the IPSs and the ACTH results obtained in subsequent IPSS tests. METHODS: A retrospective review was performed on all cases between 1998 and 2013 involving patients at a single institution who underwent IPSS for radiographically equivocal pituitary microadenomas. Cases were reviewed for tumor laterality noted on either operative or pathology reports, as well as the presence of angiographic evidence of cross-filling between the sinuses. In addition, ACTH levels from the right and left IPSs were documented at baseline and at 2, 5, and 10 minutes after corticotropin-releasing hormone (CRH) administration. A ratio of the change in ACTH levels measured at the time of maximal response (10 minutes) versus the levels measured at the initial response (2 minutes) was computed for each patient and compared between patients by their angiographic cross-filling status. RESULTS: There were 41 patients with a histopathologically confirmed right- or left-sided ACTH-secreting pituitary microadenoma who underwent preoperative IPSS. Among these patients, 28 (68%) showed angiographic evidence of cross-filling between the IPSs, and 13 showed no cross-filling. On average, ACTH levels increased by a factor of 3.91 ± 0.77 in the contralateral IPS in patients with angiographic cross-filling, compared with a factor increase of only 1.80 ± 0.27 in patients without cross-filling (p = 0.014). In comparison, ACTH levels increased by a factor of 2.01 ± 0.57 in the ipsilateral IPS in patients with cross-filling, and by 8.78 ± 7.30 in those without cross-filling (p = 0.373). CONCLUSIONS: The presence of angiographic cross-filling, suggestive of a greater degree of vascular channel networking between the right and left IPS, is a significant factor influencing the measured rates of change of ACTH in IPSS and may impact the specificity of this test to accurately determine microadenoma laterality in the preoperative setting.

A False Pituitary Tumor.

A false pituitary tumor describes pituitary enlargement due to intracranial hypotension. Reported previously primarily in the neurological literature, we present this case referred to endocrinology for evaluation of a pituitary mass. A 24-year-old male was referred to endocrinology for evaluation of pituitary enlargement without a hypo-enhancing lesion on magnetic resonance imaging (MRI). The main symptom reported was headache that was worse in the standing position and in the afternoon. He had no symptoms or signs of pituitary mass-effect, or hormone excess or deficiencies. Past medical history was relevant for a history of nerve schwannoma status post resection with subsequent spinal fusion. Biochemical evaluation of pituitary hormones was normal. Upon review of his pituitary MRI, other abnormalities seen were suggestive of intracranial hypotension. Based on his history and imaging findings, he was diagnosed with intracranial hypotension causing a "false pituitary tumor" rather than pituitary enlargement or abnormality. Further evaluation revealed multiple spinal leaks that were patched. His symptoms subsided within a few days of repair. Endocrinologists should be aware of the possible misdiagnosis of a pituitary mass due to intracranial hypotension.

Clinical and imaging outcomes of 100 patients with cerebrospinal fluid-venous fistulas treated by transvenous embolization.

BACKGROUND: Cerebrospinal fluid-venous fistulas (CSFVF) are a common cause of spontaneous intracranial hypotension (SIH). Transvenous embolization has emerged as a reliable treatment option. We review the clinical presentation, imaging, and clinical outcomes of 100 consecutive CSFVF patients who underwent embolization over 2 years. METHODS: Baseline clinical characteristics, imaging findings (including Bern SIH score), technical outcomes, and long-term imaging and clinical outcomes were collected. All patients had at least 3 months of clinical follow-up and had baseline MRI. 99/100 patients underwent follow-up imaging at ≥3 months post-treatment. RESULTS: 100 patients were included. Mean imaging and clinical follow-up duration was 8.3±7.7 months and 15.0±6.8 months, respectively. The mean duration of symptoms before embolization was 40.9±52 months. Mean baseline Bern SIH score was 5.9±3.3. The most common baseline symptoms were headache (96 patients), tinnitus (55 patients), and cognitive dysfunction (44 patients). Technical success rate was 100%. Mean post-treatment Bern SIH score was 0.9±1.6 (P<0.0001). Following treatment, 95% of patients reported significant improvement or resolution in symptoms (58 patients reporting resolution and 37 reporting improvement). 5 patients reported no improvement. There were no major procedural or periprocedural complications. 10 patients had minor procedural complications that did not result in any change in management (Onyx emboli, venous perforation). 19 patients had rebound intracranial hypertension requiring acetazolamide therapy. 7 patients had recurrent fistula at the initially treated level. CONCLUSIONS: Transvenous embolization of CSFVF in SIH patients is safe and effective with a 95% treatment response, significant improvement in imaging outcomes, and a very low rate of complications.

Clinical and Imaging Outcomes of Surgically Repaired Cerebrospinal Fluid-Venous Fistulas Identified by Lateral Decubitus Digital Subtraction Myelography.

OBJECTIVE: To describe clinical and radiographic outcomes of surgical repair of cerebrospinal fluid-venous fistula (CVF), an increasingly recognized cause of spontaneous intracranial hypotension that is poorly responsive to epidural blood patch (EBP). METHODS: Retrospective review identified adult patients who had lateral decubitus digital subtraction myelography indicative of cerebrospinal fluid leak at Mayo Clinic between November 2018 and February 2020, with clearly localized CVF, followed by surgical treatment. Patients without available imaging before or after surgery were excluded. History of EBP and clinical response to EBP were evaluated along with surgical outcomes. RESULTS: Of 25 patients with CVF who met protocol criteria and were included in the data analysis, 22 (88%) received EBP, but clinical benefit lasting ≥4 weeks occurred in only 2 of 22 (9%). Headache was the most prominent preoperative feature among patients (24/25; 96%). Following surgery, 18 of 24 (75%) patients had complete headache improvement, 4 (17%) had partial improvement, and 2 (8%) had no improvement. Ten of 25 (40%) patients reported cognitive disturbance at baseline; at follow-up, 5 of 10 (50%) had complete improvement, 3 (30%) had partial improvement, and 2 (20%) had no improvement. On postoperative brain magnetic resonance imaging, 6 of 25 (24%) patients had complete resolution of findings by Bern score criteria, 18 (72%) showed partial improvement, and 1 (4%) patient showed no improvement. Adverse events were minor and included surgical site pain and paresthesias. CONCLUSIONS: Surgical repair of CVF resulted in improvements in headache and other symptoms, with few side effects.

Surgical management of sacral schwannomas: a 21-year mayo clinic experience and comparative literature analysis.

INTRODUCTION: Sacral and presacral schwannomas are rare, accounting for a minority of spinal schwannomas. We present our institution's experience surgically treating spinal schwannomas and compare it to the literature. METHODS: Data were collected for 27 patients treated surgically for sacral or presacral schwannoma between 1997 and 2018 at all Mayo Clinic locations and 93 patients in the literature. Kaplan-Meier disease-free survival analysis was conducted. Unpaired two-sample t tests and Fisher's exact tests assessed statistical significance between groups. RESULTS: Our patients and those in the literature experienced a similar age at diagnosis (49.9 y/o. vs 43.4 y/o., respectively). Most of our patients (59.3%) reported full recovery from symptoms, while a minority reported partial recovery (33.3%) and no recovery (11.1%). A smaller percentage in the literature experienced full recovery (31.9%) and partial recovery (29.8%) but also no recovery (1.1%). Our patients experienced fewer complications (14.8% versus 25.5%). Disease-free survival curves for all patients showed no significant variation in progression by extent of resection of schwannoma (log-rank P = 0.26). No lesion progression was associated with full or partial symptom improvement (p = 0.044), and female patients were more likely to undergo resection via a posterior approach (p = 0.042). CONCLUSION: Outcomes of patients with sacral or presacral schwannomas vary based on patient demographics, tumor characteristics, symptoms, and surgical treatment. Among the range of symptoms experienced by these patients, the most common is pain. Prognosis improves and overall survival is high when the surgical approach towards sacral schwannomas is prepared and executed appropriately.

Clinical and imaging outcomes of cerebrospinal fluid-venous fistula embolization.

BACKGROUND: We report outcomes of spontaneous intracranial hypotension (SIH) patients who underwent transvenous embolization of cerebrospinal fluid-venous fistulas (CSFVFs) confirmed on digital subtraction myelography (DSM) performed at our institution. METHODS: This is a retrospective evaluation of a prospectively collected database of SIH patients who underwent transvenous embolization of CSFVFs. Only patients who had fistulas confirmed on DSM performed at our institution were included. All patients had a baseline MRI and an MRI performed at least 90 days post-embolization, as well as clinical evaluation using the six item Headache Impact Test (HIT-6) and the Patient Global Impression of Change (PGIC) scales. Paired t-test was used to report changes in Bern MRI scores and HIT-6 scores at follow-up. RESULTS: 40 patients were included (29 female, 11 male). Mean age was 57.4±10.3 years. Mean Bern score improved from 5.7±3.0 at baseline to 1.3±2.0 at follow-up (p<0.0001). Mean HIT-6 score at baseline was 67.2±11.1 and at follow-up was 41.5±10.1 (p<0.0001). Median PGIC was 1, with 36 patients (90.0%) reporting at least minimal improvement and 32 patients (82.5%) reporting much or very much improvement. Complications included persistent local site pain in 12 patients (30%), suspected rebound intracranial hypertension requiring medical intervention in 7 patients (17.5%), and asymptomatic tiny Onyx emboli to the lungs in 3 patients (7.5%). CONCLUSIONS: Transvenous embolization of CSFVFs using Onyx is safe and effective, resulting in significant improvement in headache and overall clinical outcomes in nearly 90% of patients, and substantial improvements in brain MRI abnormalities.

Surgical outcomes of medically failed prolactinomas: a systematic review and meta-analysis.

PURPOSE: In Prolactinomas, surgery or radiation are reserved for DA failure due to tumor resistance, intolerance to medication-induced side-effects, or patient preference. This systematic review and meta-analysis summarizes the currently available literature regarding the effectiveness of surgery to treat prolactinomas in patients who have failed DA therapy. METHOD: A literature search was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for studies that reported outcomes of medically resistant and intolerant prolactinoma treated surgically. RESULTS: 10 articles (Total N = 816, Surgery N = 657) met the inclusion criteria. 38% of patients who underwent surgery following DA failure achieved remission without need for further treatment (p < 0.001, I2 = 67.09%) with a median follow-up of 49.2 +/- 40 months. 62% achieved remission with multimodal treatment (p < 0.001, I2 = 93.28%) with a median follow-up of 53 +/- 39.8 months. 16% of cases demonstrated recurrence after early remission (p = 0.02, I2 = 62.91%) with recurrence occurring on average at 27 +/- 9 months. Overall, 46% of patients required reinstitution of postoperative DA therapy at last follow up (p < 0.001, I2 = 82.57%). Subgroup analysis of macroprolactinoma and microprolactinoma has demonstrated that there is no statistical significance in achieving long-term remission with surgery stand-alone in macroprolactinoma group (p = 0.49) although 43% of patients were able to achieve remission with multimodal therapy at last follow-up in the same group (p < 0.001, I2 = 86.34%). CONCLUSIONS: This systematic review and meta-analysis revealed 38% of operated patients achieved remission, while 62% achieved remission when additional modes of therapy were implemented. Therefore, although surgery has not been initial therapeutic choice for prolactinoma, it plays a significant role in medically failed prolactinoma care.

Pituitary Tumor Surgery: Comparison of Endoscopic and Microscopic Techniques at a Single Center.

OBJECTIVE: To understand the transition from microscopic surgery (MS) to endoscopic surgery (ES) on the pituitary across the United States, we assessed a single institution practicing both procedures to discern advantages and disadvantages for each. PATIENTS AND METHODS: Retrospective institutional chart review of 534 patients in a large practice over a 6-year period (January 1, 2014, to December 31, 2019) comparing a single MS neurosurgeon with a single ES neurosurgeon operating on the same days. RESULTS: In this series, 14% (n=75) of patients had a prior operation, there were no carotid artery injuries, the overall risk for a postoperative infection was 0.4% (n=2), and risk for a postoperative cerebrospinal fluid leak requiring treatment was 2.0% (n=11). Mean ± SD hospital stay was 1.3±0.04 days; readmission for any reason within 30 days occurred in 3.4% (n=18) of patients. The mean volumetric resection for MS was 86.9%±1.7% and for ES was 91.7%±1.3% (P=.03). There was a higher rate of notable events (P=.015) with MS, but MS had 16% lower cost and operative times were 48 minutes shorter than for ES (83±7 vs 131±6 minutes). The ES required substantially fewer postoperative secondary treatments such as radiation therapy (P=.003). CONCLUSION: Pituitary surgery is a very safe and effective procedure regardless of technique. The MS has shorter operative times and overall lower cost. The ES results in increased volumetric resection and fewer secondary treatments. Both techniques can be valuable to a large practice, and understanding these niches is important when selecting optimal approaches to pituitary surgery for a given patient.

Clinical, biological, radiological, and pathological comparison of sparsely and densely granulated somatotroph adenomas: a single center experience from a cohort of 131 patients with acromegaly.

PURPOSE: Growth hormone-producing pituitary adenomas are divided into two clinically relevant histologic subtypes, densely (DG-A) and sparsely (SG-A) granulated. Histologic subtype was evaluated in a large cohort of patients with acromegaly, separating DG-A and SG-A, and correlated with clinicopathological characteristics. METHODS: Patients with acromegaly undergoing surgery as initial therapy between 1995 and 2015 were identified. Histologic subtype was determined by keratin expression pattern with CAM5.2 and correlated with clinical and imaging parameters, somatostatin receptor subtype 2 (SST2) expression, post-surgical remission rate, and application of a prognostic scoring system incorporating proliferation and invasiveness. RESULTS: One hundred thirty-one patients were included. Tumors were classified as DG-A (75, 57.3%), SG-A (29, 22.1%), intermediate (I-A) (9, 6.9%), and unclassified (18, 13.7%) when CAM5.2 was negative. DG-A and I-A were combined for analysis (DG/I-A) and compared to SG-A. Age, gender, proliferation, and post-surgical remission did not differ. SG-A were larger [2 vs. 1.5 cm (median), p = 0.03], more frequently invasive [65.5% vs. 32.9%, p = 0.004], associated with higher MRI T2-weighted signal ratio [1.01 vs. 0.82 (median), p = 0.01], showed lower SST2 expression (p < 0.0001), and scored higher in the prognostic classification (p = 0.004). Surgical remission occurred in 41.7% DG/I-A and 41.4% SG-A (p = 1.0). On multivariate analysis, absence of invasion (p = 0.009) and lower pre-operative IGF-1 index (p = 0.0002) were associated with post-surgical remission. CONCLUSION: CAM5.2 allowed distinction between DG/I-A and SG-A in most but not all cases. Histologic subtype did not predict surgical outcome. Absence of invasion and lower pre-operative IGF-1 index were the only significant predictors of post-surgical remission in this cohort.

Outcomes in single-level posterior cervical spine surgeries performed in the sitting and prone positions.

OBJECTIVE: The sitting or semisitting position in neurosurgery allows for several technical advantages, including improved visualization of the surgical field. However, it has also been associated with an increased risk of venous air embolisms and positioning-related complications that limit its commonplace adoption. The authors report a large, single-center series of cervical spine procedures performed with patients in the sitting or prone position in order to assess the perceived risk of intraoperative and postoperative complications associated with the sitting position. METHODS: Noninstrumented, single-level posterior cervical spine procedures performed with patients in the sitting/semisitting or prone position from 2000 to 2016 at a single institution were reviewed. Institutional abstraction tools (DataMart and Chart Plus) were used to collect data from the medical records. The two positions were compared with regard to preoperative factors, intraoperative variables, and postoperative outcomes. Multivariable logistic regression models were fitted for 30-day readmission, 30-day return to the operating room, and complication rates. RESULTS: A total of 750 patients (sitting, n = 480; prone, n = 270) were analyzed. The median age was 53 years for those who underwent surgery in the prone position and 50 years for those who underwent surgery in the sitting position (IQRs 45-62 years and 43-60 years, respectively), and 35% of the patients were female. Sitting cases were associated with significantly longer anesthetic times (221 minutes [range 199-252 minutes] vs 205 minutes [range 179-254 minutes]) and operative times (126 minutes [range 101-163 minutes] vs 149 minutes [120-181 minutes]). Cardiorespiratory events in the postanesthesia care unit (PACU) were comparable between the two groups, with the exception of episodes of apnea (2.6% vs 0.6%, p = 0.041) and hypoventilation (4.4% vs 0.8%, p < 0.003), which were more frequent in the prone-position cohort. On multivariable analysis, the effect of the sitting versus the prone position was not significant for 30-day readmission (OR 0.77, 95% CI 0.34-1.71, p = 0.52) or reoperation (OR 0.71, 95% CI 0.31-1.60, p = 0.40). The sitting position was associated with lower odds of developing any complication (OR 0.31, 95% CI 0.16-0.62, p < 0.001). CONCLUSIONS: Based on the intraoperative and postoperative complications chosen in this study, the sitting position confers a similar safety profile to the prone position. This can be explained by a more anatomic positioning accounting for reduced temporary neurological deficits and reduced PACU-associated hypoventilation noted in this series. Nevertheless, the findings may also reflect institutional familiarity, experience, and mastery of this position type, and outcomes may not reflect practices in general.

Pituitary adenomas in the setting of multiple endocrine neoplasia type 1: a single-institution experience.

OBJECTIVE: Multiple endocrine neoplasia type 1 (MEN1) is a rare, autosomal-dominant tumor disorder characterized by the development of pituitary tumors and other endocrine neoplasms. Diagnosis is made clinically based on the development of 2 or more canonical lesions (parathyroid gland, anterior pituitary, and enteropancreatic tumors) or in family members of a patient with a clinical diagnosis of MEN1 and the occurrence of one of the MEN1-associated tumors. The goal of this study was to characterize pituitary tumors arising in the setting of MEN1 at a single institution. The probability of tumor progression and the likelihood of surgical intervention in patients with asymptomatic nonfunctional pituitary adenomas were also analyzed. METHODS: A retrospective review of a prospectively maintained institutional database was performed for patients with MEN1 diagnosed from 1970 to 2017. Data included patient demographics, tumor characteristics, treatment strategies, and outcomes. RESULTS: A review of the database identified 268 patients diagnosed with MEN1, of whom 158 (59%) were female. Among the 268 patients, 139 (51.8%) had pituitary adenomas. There was a higher prevalence in women than in men (65% vs 35%, p < 0.005). Functional adenomas (57%) were more common. Prolactin-secreting adenomas were the most common functional tumors. Macroadenomas were seen in 27% of patients and were more likely to be symptomatic and locally aggressive (p < 0.001). Forty-nine patients (35%) underwent transsphenoidal resection at some point during their disease course. In 52 patients who were initially observed with MEN1 asymptomatic nonfunctional adenomas, only 5 (10%) progressed to need surgery. In MEN1 patients, an initial parathyroid lesion is most likely followed in order by pituitary, pancreatic, adrenal, and, finally, rare carcinoid tumors. CONCLUSIONS: Asymptomatic nonfunctional pituitary adenomas in patients with MEN1 may be followed safely with MRI. In this series, parathyroid tumors developed at the lowest median age of all cardinal tumors, and development of additional cardinal MEN1 lesions followed a predictable pattern. This pattern of disease progression could have significant implications for disease surveillance in clinical practice and may help to target clinical resources to the lesions most likely to develop next. This may aid with early detection and treatment and warrants further study.

Can Lipomatosis of the Nerve Occur or Extend Intradurally?

BACKGROUND: Diverse adipose lesions can affect peripheral nerves, including an intrinsic disorder known as lipomatosis of nerve (LN). This condition leads to massive nerve enlargement and has often been associated with nerve territory overgrowth. Although LN has been well documented as a peripheral lesion, it is uncertain whether LN can occur or extend intradurally. METHODS: In the present 2-part study, we searched our institutional database and the world literature to identify any case of LN occurring or extending intradurally. Strict pathognomonic imaging and histopathologic features of LN were required to be present. RESULTS: We did not identify any case of LN that had occurred or extended intradurally in our institution. Specifically, in our database, we found no case of intradural LN, and an evaluation of the imaging studies of proximal examples of LN did not show any extension proximal to the spinal foramen. Our literature search identified 208 reports of potential interest, of which only 3 had reported on spinal LN. Although 2 of the 3 cases showed some similarities to LN, none had demonstrated features diagnostic for LN and none had demonstrated nerve territory overgrowth. A review of 16 cases of LN in proximal locations summarized in a recently reported systematic review did not reveal any cases with LN proximal to the foramen or in an intradural location. CONCLUSION: A review of our institutional cases and reported cases did not show any example of LN extending or occurring intradurally. It appears that LN is a benign tumor-like nerve lesion that is without a central location, unlike more well-known tumors such as schwannomas.

Total lumbar facetectomy without fusion: short and long term follow-up in a single surgeon series.

BACKGROUND: Total lumbar facetectomy may be advantageous for exposure or to completely free a constricted nerve root. OBJECTIVE: We retrospectively reviewed a single surgeon series without fusion for short and long term outcomes regarding radicular pain relief, subsequent relevant surgeries, and any identifiable instability. METHODS: All operations in which a single, total lumbar facetectomy was performed were reviewed. A total of 222 patients were identified with a minimal follow-up of 3 months; 187 (84.2%) were available for long term follow-up ≥1 year by continued accessible health care records, correspondence, or mailed questionnaire. RESULTS: Short term success (3-month follow-up) for radicular pain relief in 222 patients found the following results: 176 patients (79.3%) had no pain or minimal pain, and 16 patients (7.2%) were improved, and thus resulting in 192 (86.5%) with no pain, or improved radicular pain. 30 patients (13.5%) were postoperative failures at 3 months. Long term follow-up ≥1 year was available for 187 patients (84.2%); (range 1-17 years; mean 7 years); found the following results: 23/30 (76.6%) short term surgical failures remained failures in long term follow-up with (7 patients) or without (16 patients) further surgery of any kind; 13/16 improved patients at long term follow-up remained improved (6), were pain free (6), or worse (1); 19/151 no or minimal pain patients at long term follow-up recurred or worsened by 1 year or longer, 12/19 pursued a second surgery with (9) or without (4) fusion and many improved. A total of 13 patients had a subsequent fusion operation (6.95%). DISCUSSION: Most patients do well in the short term for radicular pain relief. Most patients continue to do well in long term follow-up. Surgically induced clinical instability is uncommon in this highly selected series.

Characterizing and predicting the Nelson-Salassa syndrome.

OBJECTIVE Nelson-Salassa syndrome (NSS) is a rare consequence of bilateral adrenalectomy (ADX) for refractory hypercortisolism due to Cushing disease (CD). Although classically defined by rapid growth of a large, invasive, adrenocorticotropin hormone (ACTH)-secreting pituitary tumor after bilateral ADX that causes cutaneous hyperpigmentation, visual disturbance, and high levels of ACTH, clinical experience suggests more variability. METHODS The authors conducted a retrospective chart review of all patients 18 years and older with a history of bilateral ADX for CD, adequate pituitary MRI, and at least 2 years of clinical follow-up. Statistical tests included Student's t-test, chi-square test, Fisher's exact test, multivariate analysis, and derived receiver operating characteristic curves. RESULTS Between 1956 and 2015, 302 patients underwent bilateral ADX for the treatment of hypercortisolism caused by CD; 88 had requisite imaging and follow-up (mean 16 years). Forty-seven patients (53%) had radiographic progression of pituitary disease and were diagnosed with NSS. Compared with patients who did not experience progression, those who developed NSS were significantly younger at the time of CD diagnosis (33 vs 44 years, p = 0.007) and at the time of bilateral ADX (35 vs 49 years, p = 0.007), had larger tumors at the time of CD diagnosis (6 mm vs 1 mm, p = 0.03), and were more likely to have undergone external-beam radiation therapy (EBRT, 43% vs 12%, p = 0.005). Among NSS patients, the mean tumor growth was 7 mm/yr (SE 6 mm/yr); the median tumor growth was 3 mm/yr. Prevalence of pathognomonic symptoms was low; the classic triad occurred in 9%, while hyperpigmentation without visual field deficit was observed in 23%, and 68% remained asymptomatic despite radiographic disease progression. NSS required treatment in 14 patients (30%). CONCLUSIONS NSS is a prevalent sequela of CD after bilateral ADX and affects more than 50% of patients. However, although radiological evidence of NSS is common, it is most often clinically indolent, with only a small minority of patients developing the more aggressive disease phenotype characterized by clinically meaningful symptoms and indications for treatment. Young age at the time of CD diagnosis or treatment with bilateral ADX, large tumor size at CD diagnosis, and EBRT are associated with progression to NSS and may be markers of aggressiveness.

Perianesthetic Management of Patients With Thyroid-Stimulating Hormone-Secreting Pituitary Adenomas.

BACKGROUND: Thyroid-stimulating hormone (TSH)-secreting pituitary adenomas are a rare cause of secondary hyperthyroidism. Anesthetic management of these patients has not been formally described in the literature. MATERIALS AND METHODS: Patients who underwent resection of a TSH-secreting pituitary adenoma during 1987 to 2012 at a single institution were identified. Preoperative thyroid hormone state, anesthetic management, and outcome were recorded. Hemodynamic associations with intraoperative events were compared between those who were hyperthyroid and euthyroid at the time of surgery. RESULTS: Of 2268 patients having transsphenoidal resection of a pituitary tumor, 19 (0.84%) had resection of a TSH-secreting adenoma. At the time of surgery, 6 (32%) were hyperthyroid, 11 (58%) were euthyroid, and 2 (10%) were hypothyroid based on serum thyroxine concentration. General anesthesia was maintained with a potent inhaled anesthetic in all patients, and included nitrous oxide in 18 of 19 (95%). Seventeen (90%) had an arterial catheter placed for surgery. Only 1 patient (5%) required an intraoperative blood transfusion. There were no significant differences in heart rate or blood pressure at induction of anesthesia, upon intranasal injection of local anesthetic containing epinephrine, or upon emergence from anesthesia, between patients who were chemically hyperthyroid or euthyroid. Twelve of 19 (63%) had tumor extension beyond the sella turcica. Common complications were nausea and vomiting (42%), diabetes insipidus (32%), and temporary or permanent hypopituitarism (42%). CONCLUSIONS: Patients having resection of TSH-secreting pituitary adenomas can present in any thyroid state. An awareness of risks and potential complications in patients with TSH-secreting adenomas can help tailor perioperative care.

SURGICAL OUTCOMES OF PROLACTINOMAS IN RECENT ERA: RESULTS OF A HETEROGENOUS GROUP.

OBJECTIVE: Prolactinomas are primarily treated with medical therapy. Given the efficacy of dopamine agonists (DAs), surgery has remained a second-line treatment option. Despite medical therapy, some tumors display resistance and/or patients maybe intolerant of DA and require alternative treatment options. We examined the indications, efficacy, and safety of pituitary surgery for the treatment of prolactinomas. METHODS: We performed a retrospective analysis of all patients who had surgery for a prolactinoma at our institution from January 1993 to October 2014. RESULTS: Seventy-eight patients (46 females, mean age 32 years) with a median follow-up of 12 months were analyzed. Macroprolactinomas accounted for 65% (51/78) of tumors. The most common indication for surgery in microprolactinomas was medication intolerance (37%, 10/27) and medication failure (33%, 17/51) in macroprolactinomas. DA therapy had been tried in 76% (59/78) patients prior to surgery. Following surgery, long-term remission was seen in 72% (18/25) of micro-adenomas and 20% (10/49) of macro-adenomas (32% [10/32] in those without cavernous sinus invasion). Despite persistent disease in those with macro-adenomas (34% [13/38]) were able to remain off medication. Early surgical failure was more common in males (P = .004) and those with large (P≤.001) or atypical (P = .003) adenomas. CONCLUSION: Surgery can result in prolonged remission in 72% of microprolactinomas. Despite lower remission rates among macroprolactinomas, a third of patients with persistent disease did not require medical therapy. Therefore, surgery remains an alternative effective treatment option, particularly for those who are intolerant or resistant to medical therapy. ABBREVIATIONS: ACTH = adrenocorticotropic hormone CI = confidence interval CSF = cerebrospinal fluid DA = dopamine agonist IQR = interquartile range MIB-1 = methylation inhibiting binding protein-1 VF = visual field.

Contemporary analysis of the intraoperative and perioperative complications of neurosurgical procedures performed in the sitting position.

OBJECTIVE Historically, performing neurosurgery with the patient in the sitting position offered advantages such as improved visualization and gravity-assisted retraction. However, this position fell out of favor at many centers due to the perceived risk of venous air embolism (VAE) and other position-related complications. Some neurosurgical centers continue to perform sitting-position cases in select patients, often using modern monitoring techniques that may improve procedural safety. Therefore, this paper reports the risks associated with neurosurgical procedures performed in the sitting position in a modern series. METHODS The authors reviewed the anesthesia records for instances of clinically significant VAE and other complications for all neurosurgical procedures performed in the sitting position between January 1, 2000, and October 8, 2013. In addition, a prospectively maintained morbidity and mortality log of these procedures was reviewed for instances of subdural or intracerebral hemorrhage, tension pneumocephalus, and quadriplegia. Both overall and specific complication rates were calculated in relation to the specific type of procedure. RESULTS In a series of 1792 procedures, the overall complication rate related to the sitting position was 1.45%, which included clinically significant VAE, tension pneumocephalus, and subdural hemorrhage. The rate of any detected VAE was 4.7%, but the rate of VAE requiring clinical intervention was 1.06%. The risk of clinically significant VAE was highest in patients undergoing suboccipital craniotomy/craniectomy with a rate of 2.7% and an odds ratio (OR) of 2.8 relative to deep brain stimulator cases (95% confidence interval [CI] 1.2-70, p = 0.04). Sitting cervical spine cases had a comparatively lower complication rate of 0.7% and an OR of 0.28 as compared with all cranial procedures (95% CI 0.12-0.67, p < 0.01). Sitting cervical cases were further subdivided into extradural and intradural procedures. The rate of complications in intradural cases was significantly higher (OR 7.3, 95% CI 1.4-39, p = 0.02) than for extradural cases. The risk of VAE in intradural spine procedures did not differ significantly from sitting suboccipital craniotomy/craniectomy cases (OR 0.69, 95% CI 0.09-5.4, p = 0.7). Two cases (0.1%) had to be aborted intraoperatively due to complications. There were no instances of intraoperative deaths, although there was a single death within 30 days of surgery. CONCLUSIONS In this large, modern series of cases performed in the sitting position, the complication rate was low. Suboccipital craniotomy/craniectomy was associated with the highest risk of complications. When appropriately used with modern anesthesia techniques, the sitting position provides a safe means of surgical access.

Superficial siderosis of the central nervous system associated with incomplete dural closure following posterior fossa surgery: report of 3 cases.

This report reviews a series of 3 patients who developed superficial siderosis following posterior fossa operations in which dural closure was incomplete. In all 3 patients, revision surgery and complete duraplasty was performed to halt the progression of superficial siderosis. Following surgery, 2 patients experienced resolution of their CSF xanthochromia while 1 patient had reduced CSF xanthochromia. In this paper the authors also review the etiology, pathophysiology, diagnosis, and treatment of this condition. The authors suggest that posterior fossa dural patency and pseudomeningocele are risk factors for the latent development of superficial siderosis and recommend that revision duraplasty be performed in patients with posterior fossa pseudomeningoceles and superficial siderosis to prevent progression of the disease.

Management and outcomes of pituitary apoplexy.

OBJECT: This study was undertaken to analyze the predisposing factors, clinical presentation, therapeutic management, and clinical recovery in patients with pituitary apoplexy, with an emphasis on the long-term visual, endocrine, and functional outcomes. METHODS: The authors performed a retrospective analysis of consecutive cases involving patients treated at Mayo Clinic between 1992 and 2013. Patients were included in the study only if they had 1) abrupt onset of severe headache or visual disturbance in the presence of a pituitary adenoma and 2) radiological or surgical confirmation of a pituitary mass. The primary endpoints of analysis were the visual (ocular motility, visual fields, and visual acuity), endocrine, and functional outcomes (using the modified Rankin Scale). RESULTS: Eighty-seven patients were identified (57 males and 30 females, mean age 50.9 years, range 15-91 years). Twenty-two patients (25.3%) had a known pituitary adenoma. Hypertension was the most common associated factor (39%). Headache was the most frequent presenting symptom (89.7%), followed by visual abnormalities (47.1%). Cranial nerve palsies were present in 39% and visual field defects in 34.1%. MRI detected hemorrhage in 89% patients, as compared with 42% detected by CT scan. Sixty-one patients (70.1%) underwent surgery during acute hospitalization (median time from apoplexy 5 days, IQR 3-10 days), 8 (9.2%) had delayed surgery, and 18 (20.7%) were treated conservatively. Histopathological examination revealed adenoma with pure necrosis in 18 (30%), pure hemorrhage in 4 (6.7%), and both in 6 (10%) patients. Four patients died during hospitalization. The average duration of follow-up was 44.2 ± 43.8 months. All survivors were independent and had complete resolution or substantial improvement in eye movements and visual fields at the last follow-up. Many patients needed long-term hormonal replacement with levothyroxine (62.7%) and cortisol (60%). Daily desmopressin was needed in 23% of all surgical patients at 3 months (versus none of the medically treated) and this requirement decreased slightly over time. Regrowth of pituitary adenoma was seen in 7 patients (8.6%). There were no statistically significant differences in any of the outcome measures across the treatment groups. CONCLUSIONS: The outcome of most patients with pituitary apoplexy is excellent. Selected patients can be managed conservatively, and patients with severe neuro-ophthalmological deficits treated with early surgery can achieve an excellent recovery.