Fredric Bruce Meyer

The transsphenoidal approach to sellar lesions is a mainstay technique in modern neurosurgical treatment of pituitary adenomas. One prominent complication following transsphenoidal surgery is the development of postoperative hyponatremia, frequently necessitating additional medical management and hospital readmission. However, the precise incidence and risk factors of postoperative hyponatremia remain unclear in the current literature. We conducted a systematic meta-analysis of 104 studies (31,676 patients) to clarify the incidence of postoperative hyponatremia and associated hospital readmission, as well as to summarize conflicting findings regarding significant risk factors of postoperative hyponatremia. The overall incidence of postoperative hyponatremia following transsphenoidal surgery was 13.3% [95% Confidence Interval (CI): 11.8–14.7%; 96 studies]. The rate of hospital readmission due to postoperative hyponatremia was 3.3% [95% CI: 2.7–3.9%; 33 studies]. Factors such as infundibular stalk deviation angle, plasma copeptin level, and Knosp grades served as more reliable predictors of postoperative hyponatremia. In contrast, conventional demographic and surgical parameters such as patient age, body mass index, sex, and extent of resection were not consistently identified as significant predictive factors. Secondary analyses revealed that prophylactic fluid restriction significantly reduced the incidence of postoperative hyponatremia from ~ 13.1% to ~ 4.0% (Odds Ratio 3.39 [95% CI; 2.18–5.26, Z = 5.545, P < 0.001]. This meta-analysis establishes definitive ‘benchmarks’ for anticipated complications after transsphenoidal surgery while highlighting important factors such as prophylactic fluid restriction protocols as a key source of inter-study variability. In addition, this study summarizes the congruence of the predictive factors thought to be influential in leading to postoperative hyponatremia, highlighting key areas of (dis)agreement.

OBJECTIVE: Pineal cyst (PC) is a relatively common true cyst in the pineal gland. Its long-term natural course remains ill defined. This study aims to evaluate the long-term natural history of PC and examine MRI risk factors for cyst growth and shrinkage to help better define which patients might benefit from surgical intervention. METHODS: The records and MRI of 409 consecutive patients with PC were retrospectively examined (nonsurgical cohort). Cyst growth and shrinkage were defined as a ≥ 2-mm increase and decrease in cyst diameter in any direction, respectively. In addition to size, MRI signal intensity ratios were analyzed. RESULTS: The median radiological follow-up period was 10.7 years (interquartile range [IQR] 6.4–14.3 years). The median change in maximal diameter was −0.6 mm (IQR −1.5 to 1.3 mm). During the observation period, cyst growth was confirmed in 21 patients (5.1%). Multivariate logistic regression analysis revealed that only age (odds ratio [OR] 0.96, 95% confidence interval [CI] 0.93–0.99, p < 0.01) was significantly associated with cyst growth. No patient required resection during the observation period. Cyst shrinkage was confirmed in 57 patients (13.9%). Multivariate analysis revealed that maximal diameter (OR 1.22, 95% CI 1.12–1.35, p < 0.01) and cyst CSF T2 signal intensity ratio (OR 9.06, 95% CI 1.38–6.62 × 10¹, p = 0.02) were significantly associated with cyst shrinkage. CONCLUSIONS: Only 5% of PCs, mainly in patients younger than 50 years of age, have the potential to grow, while cyst shrinkage is more likely to occur across all age groups. Younger age is associated with cyst growth, while larger diameter and higher signal intensity on T2-weighted imaging are associated with shrinkage. Surgery is rarely needed for PCs, despite the possibility of a certain degree of growth.

BACKGROUND: Pituitary abscess is a rare clinical entity, typically precipitated by Staphylococcus , Pseudomonas , or Aspergillus infection. Although Nocardia species–associated central nervous system abscesses have been documented in immunocompromised patients, no case of Nocardia pituitary abscesses has been previously reported. OBSERVATIONS: A 44-year-old man presented with hemoptysis and was found to have a cavitary right lung nodule, which was presumed histoplasmosis, prompting antifungal treatment. Several months later, he developed panhypopituitarism. Magnetic resonance imaging identified a pituitary mass, which subsequently underwent transsphenoidal endoscopic biopsy. Infectious workup was negative, and the patient was discharged on intravenous ertapenem therapy. Over several months, he developed progressive headaches, and updated imaging confirmed interval enlargement of the mass with new cavernous sinus invasion. He underwent repeat endoscopic biopsy, which yielded positive cultures for Nocardia farcinica and prompted successful treatment with trimethoprim-sulfamethoxazole and linezolid. LESSONS: The current study highlights a previously unreported clinical entity, the first pituitary abscess attributable to Nocardia sp. or N. farcinica, which arose in a young, immunocompetent individual. Although rare, atypical infections represent an important component in the differential diagnosis for sellar mass lesions.

OBJECTIVE: Surgical site infection (SSI) is a rare but significant complication after vagus nerve stimulator (VNS) placement. Treatment options range from antibiotic therapy alone to hardware removal. The optimal therapeutic strategy remains open to debate. Therefore, the authors conducted this retrospective multicenter analysis to provide insight into the optimal management of VNS-related SSI (VNS-SSI). METHODS: Under institutional review board approval and utilizing an institutional database with 641 patients who had undergone 808 VNS-related placement surgeries and 31 patients who had undergone VNS-related hardware removal surgeries, the authors retrospectively analyzed VNS-SSI. RESULTS: Sixteen cases of VNS-SSI were identified; 12 of them had undergone the original VNS placement procedure at the authors’ institutions. Thus, the incidence of VNS-SSI was calculated as 1.5%. The mean (± standard deviation) time from the most recent VNS-related surgeries to infection was 42 (± 27) days. Methicillin-sensitive staphylococcus was the usual causative bacteria (58%). Initial treatments included antibiotics with or without nonsurgical procedures (n = 6), nonremoval open surgeries for irrigation (n = 3), generator removal (n = 3), and total or near-total removal of hardware (n = 4). Although 2 patients were successfully treated with antibiotics alone or combined with generator removal, removal of both the generator and leads was eventually required in 14 patients. Mild swallowing difficulties and hoarseness occurred in 2 patients with eventual resolution. CONCLUSIONS: Removal of the VNS including electrode leads combined with antibiotic administration is the definitive treatment but has a risk of causing dysphagia. If the surgeon finds dense scarring around the vagus nerve, the prudent approach is to snip the electrode close to the nerve as opposed to attempting to unwind the lead completely.

Pediatric pituitary adenomas (PPAs) are rare neoplasms with a propensity for unusual presentations and an aggressive clinical course. Here, the authors describe 6 highly atypical PPAs to highlight this tendency and discuss unexpected management challenges.A 14-year-old girl presented with acute hemiparesis and aphasia. MRI revealed a pituitary macroadenoma causing internal carotid artery invasion/obliteration without acute apoplexy, which was treated via emergent transsphenoidal resection (TSR). Another 14-year-old girl developed precocious galactorrhea due to macroprolactinoma, which was medically managed. Several years later, she re-presented with acute, severe, bitemporal hemianopia during her third trimester of pregnancy, requiring emergent induction of labor followed by TSR. A 13-year-old boy was incidentally diagnosed with a prolactinoma after routine orthodontic radiographs captured a subtly abnormal sella. An 18-year-old male self-diagnosed pituitary gigantism through a school report on pituitary disease. A 17-year-old boy was diagnosed with Cushing disease by his basketball coach, a former endocrinologist. A 12-year-old girl with growth arrest and weight gain was diagnosed with Cushing disease, which was initially treated via TSR but subsequently recurred and ultimately required 12 operations, 5 radiation treatments involving 3 modalities, bilateral adrenalectomy, and chemotherapy. Despite these efforts, she ultimately died from pituitary carcinoma.