Fourth cranial nerve: surgical anatomy in the subtemporal transtentorial approach and in the pretemporal combined inter-intradural approach through the fronto-temporo-orbito-zygomatic craniotomy. A cadaveric study

Despite the recent progress in surgical technology in the last decades, the surgical treatment of skull base lesions still remains a challenge. The purpose of this study was to assess the anatomy of the tentorial and cavernous segment of the fourth cranial nerve as it appears in two different surgical approaches to the skull base: subtemporal transtentorial approach and pretemporal fronto-orbito-zygomatic approach. Four human cadaveric fixed heads were used for the dissection. Using both sides of each cadaveric head, we made 16 dissections: 8 with subtemporal transtentorial technique and 8 with pretemporal fronto-orbito-zygomatic approach. The first segment that extends from the initial point of contact of the fourth cranial nerve with the tentorium (point Q) to its point of entry into its dural channel (point D) presents an average length of 13.5 mm with an extremely wide range and varying between 3.20 and 9.3 mm. The segment 2, which extends from point D to the point of entry into the lateral wall of the cavernous sinus, presents a lesser interindividual variability (mean 10.4 mm, range 15.1–5.9 mm). A precise knowledge of the surgical anatomy of the fourth cranial nerve and its neurovascular relationships is essential to safely approach. The recognition of some anatomical landmarks allows to treat pathologies located in regions of difficult surgical access even when there is an important subversion of the anatomy.     

Neurotrophic gene polymorphisms and response to psychological therapy

Therapygenetics, the study of genetic determinants of response to psychological therapies, is in its infancy. Here, we investigate whether single-nucleotide polymorphisms in nerve growth factor (NGF) (rs6330) and brain-derived neutrotrophic factor (BDNF) (rs6265) genes predict the response to cognitive behaviour therapy (CBT). Neurotrophic genes represent plausible candidate genes: they are implicated in synaptic plasticity, response to stress, and are widely expressed in brain areas involved in mood and cognition. Allelic variation at both loci has shown associations with anxiety-related phenotypes. A sample of 374 anxiety-disordered children with white European ancestry was recruited from clinics in Reading, UK, and in Sydney, Australia. Participants received manualised CBT treatment and DNA was collected from buccal cells using cheek swabs. Treatment response was assessed at post-treatment and follow-up time points. We report first evidence that children with one or more copies of the T allele of NGF rs6330 were significantly more likely to be free of their primary anxiety diagnosis at follow-up (OR=0.60 (0.42–0.85), P=0.005). These effects remained even when other clinically relevant covariates were accounted for (OR=0.62 (0.41–0.92), P=0.019). No significant associations were observed between BDNF rs6265 and response to psychological therapy. These findings demonstrate that knowledge of genetic markers has the potential to inform clinical treatment decisions for psychotherapeutic interventions.     

Verapamil-induced changes in digoxin kinetics in cirrhosis

Summary The influence of a single low dose of verapamil (80 mg) on the serum levels of digoxin (single dose of 0.5 mg) was studied in 6 patients with hepatic cirrhosis and in 6 healthy volunteer controls. In the cirrhotic patients verapamil increased the peak serum level and the total AUC of digoxin by 98% and 32%, respectively. There was an associated 23% decrease in the renal digoxin clearance. In normal subjects only marginal alterations in digoxin kinetics were observed following verapamil administration. The results indicate that cirrhosis magnifies the influence of verapamil on digoxin kinetics.     

Therapeutic strategies in Crohn’s disease in an emergency surgical setting

Crohn’s disease (CD) remains a chronic, incurable disorder that presents unique challenges to the surgeon. Multiple factors must be considered to allow development of an appropriate treatment plan. Medical therapy often precedes or complements the surgical management. The indications for operative management of CD include acute and chronic disease complications and failed medical therapy. Elective surgery comes into play when patients are refractory to medical treatment if they have an obstructive phenotype. Toxic colitis, acute obstruction, perforation, acute abscess, or massive hemorrhage represent indications for emergency surgery. These patients are generally in critical conditions and present with intra-abdominal sepsis and a preoperative status of immunosuppression and malnutrition that exposes them to a higher risk of complications and mortality. A multidisciplinary team including surgeons, gastroenterologists, radiologists, nutritional support services, and enterostomal therapists are required for optimal patient care and decision making. Management of each emergency should be individualized based on patient age, disease type and duration, and patient goals of care. Moreover, the recurrent nature of disease mandates that we continue searching for innovative medical therapies and operative techniques that reduce the need to repeat surgical operations. In this review, we aimed to discuss the acute complications of CD and their treatment.     

Reproductive male-mediated risk: Spontaneous abortion among wives of pesticide applicators

This study was conducted among 32 pesticide applicators occupationally exposed to pesticides to determine whether paternal exposure is associated with an increased risk of spontaneous abortion. The ratio of abortion was compared between applicators and a group of 51 food retailers (control population). The ratio of abortions/pregnancies for applicators was 0.27 and for retailers 0.07. OR for spontaneous abortion adjusted for age of wife and smoking of parents is 3.8 times greater than for the control population in the multiple logistic regression model and 7.6 times with interaction effects model.     

Endocrine hypertension in pregnancy

Hypertension is a frequent complication of pregnancy and may compromise fetal and maternal outcome. Hypertension may be pregnancy-induced, essential or secondary to endocrine disorders. Most cases of endocrine hypertension are the consequence of adrenal diseases. Pheochromocytoma, hypercorticism, primary aldosteronism or glucocorticoid-remediable aldosteronism can be present or diagnosed at any term and may cause severe hypertension. The most hazardous form of endocrine hypertension during pregnancy is pheochromocytoma because it may involve paroxysmal arrhythmia and/or hypertension during labor. Clinical clues and biological tests are similar to those used in non-pregnant subjects. Tests for tumor location are limited to ultrasound and magnetic resonance scans in order to avoid maternal and fetal irradiation. Medication to prepare for pheochromocytoma surgery uses alpha- and beta-blockers. The timing of surgery depends on the term of pregnancy at the diagnosis of the tumor.     

Effects of oral glucose administration on plasma growth hormone levels in women with polycystic ovary syndrome

Objective: To evaluate the sensitivity of GH secretion to the suppressive effect of oral glucose administration in women with polycystic ovary syndrome (PCOS).

Design: Comparison of the GH response to an oral glucose load in women with PCOS and in weight-matched normally menstruating women (controls).

Setting: Reproductive endocrinology unit.

Patient(s): Eighteen obese and 11 nonobese patients and 10 obese and 10 nonobese controls.

Intervention(s): After an overnight fast, each woman underwent a 75-g, 3-hour oral glucose tolerance test (OGTT).

Mean Outcome Measure(s): Growth hormone, glucose, and insulin responses to OGTT.

Result(s): No significant differences in the glycemic and insulinemic responses were found between the patients and the weight-matched controls. No decrease in plasma GH was observed in both obese and nonobese patients and in obese controls during the OGTT, whereas a significant GH decrease occurred in nonobese controls 60 and 120 minutes after glucose intake.

Conclusion(s): Oral glucose administration was unable to suppress GH levels in nonobese as well as in obese women with PCOS and in obese control women. These data suggest that both PCOS and obesity are associated with a reduced sensitivity of GH secretion to glucose suppression.     

Identifying clinical supply requirements for Marine Corps dental capability

The Naval Health Research Center developed and used a systematic process to review Marine Corps dental supply requirements. The approach (1) identified the dental procedures required to treat patients with dental conditions and (2) determined the consumable supplies and equipment needed to complete each procedure. By establishing the clinical requirement for each item pushed forward, the Naval Health Research Center model significantly reduced weight, cubic volume, and cost while enhancing far-forward dental capability. This effort produced a database that clarifies the relationship among dental conditions, dental procedures, consumables, and equipment when conducting authorized dental allowance list reviews, determining training requirements, and configuring supplies for future deployments.