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Brain arteriovenous malformations (bAVMs) are vascular lesions that carry significant morbidity and mortality risk upon rupture. bAVM rupture causes either intracerebral or intraventricular hemorrhage, or both. In 2014, the first results of the ARUBA trial (A Randomized Trial of Unruptured Brain Arteriovenous Malformations) were published in The Lancet, causing a paradigm shift in clinical practice and suggesting the superiority of medical treatment in terms of mortality or stroke compared with any intervention designed to obliterate the AVM. In 2020, the final results of the ARUBA trial were published. In this Viewpoint, we critically review the clinical equipoise behind the trial, highlight issues regarding external validity, and place the results of the trial in the context of other results in scientific literature of bAVMs using Bayesian inference. ARUBA is a trial of decision-making, and only proper knowledge of the nuances of its interpretation within the broader context of bAVM research can lead to proper decision-making when confronted with patients with unruptured bAVMs.

The human insula is known to be involved in auditory processing, but knowledge about its precise functional role and the underlying electrophysiology is limited. To assess its role in automatic auditory deviance detection we analyzed the EEG high frequency activity (HFA; 75–145 Hz) and ERPs from 90 intracranial insular channels across 16 patients undergoing pre-surgical intracranial monitoring for epilepsy treatment. Subjects passively listened to a stream of standard and deviant tones differing in four physical dimensions: intensity, frequency, location or time. HFA responses to auditory stimuli were found in the short and long gyri, and the anterior, superior, and inferior segments of the circular sulcus of the insular cortex. Only a subset of channels in the inferior segment of the circular sulcus of the insula showed HFA deviance detection responses, i.e., a greater and longer latency response to specific deviants relative to standards. Auditory deviancy processing was also later in the insula when compared with the superior temporal cortex. ERP results were more widespread and supported the HFA insular findings. These results provide evidence that the human insula is engaged during auditory deviance detection.

Intraoperative fluorescence guidance is a well-established surgical adjunct in high-grade glioma surgery. In contrast, the clinical use of such dyes and technology has been scarcely reported in skull base surgery.

Cavernous malformations (CM) of the central nervous system constitute rare vascular lesions. They are usually asymptomatic, which has allowed their management to become quite debatable. Even when they become symptomatic their optimal mode and timing of treatment remains controversial.

Purely intraorbital cavernomas remain rare, but still are the most common benign orbital tumors.1 These expansive lesions are now rapidly detected and adequately treated. Surgical resection is the gold standard and a definitive solution. The choice of approach varies between different possibilities, including orbitotomies, trans-sinusal routes, and transconjunctival accesses.2-4 Because the last technique is less known to the neurosurgeon, we describe here a step-by-step guide to perform it.  The technique is illustrated with the case of a 62-yr-old male with a voluminous right retroocular cavernoma. He presented a progressive right exophthalmia without visual acuity or campimetric deterioration. Because the cavernoma was purely medial from the optic nerve in the intraconal space, no osteotomy was deemed necessary to extirpate the lesion. The video shows the conjunctival dissection, followed by the medial rectus muscle being dissected, allowing us to attain the retrobulbar space in the orbit. The cavernoma is then dissected from the surroundings and reduced in volume by coagulation so its removal does not apply hyperpressure on the adjacent fragile structures. We then pursue with the closure by stitching the medial rectus muscle to the eyeball. Finally, the conjunctiva is sutured.  Postoperatively, there was no complication. A transient mydriasis due to ciliary nerve manipulation spontaneously resolved. Extirpation of the lesion was total. The patient's exophthalmia normalized over the next months. No visual or campimetric deterioration was noted at follow-up. A slight horizontal diplopia was noted after surgery, which normalized at 1 yr. The patient's consent was obtained for the procedure.

Early onset scoliosis (EOS) represent a challenge for spine surgeons. The selection of the best treatment is complex. Some patients, such as Jehovah's Witnesses who refuse blood transfusions, are at high risk of complication when surgical treatment is required because blood loss is a major cause of morbidity and postoperative transfusion rates.

Cushing's disease is a state of chronic and excessive cortisol levels caused by a pituitary adenoma

The optimal surgical treatment for giant pituitary neuroendocrine tumors(GPitNETs) is debated.

The evolution of cavernous sinus meningiomas (CSMs) might be unpredictable and the efficacy of their treatments is challenging due to their indolent evolution, variations and fluctuations of symptoms, heterogeneity of classifications and lack of randomized controlled trials. Here, a dedicated task force provides a consensus statement on the overall management of CSMs.

Midface distraction osteogenesis has become a valuable technique. Although outcome data are available from several craniofacial centers, information regarding perioperative and immediate postoperative course is scarce. This report describes seven children, aged 4 to 17 years, with syndromal craniosynostosis in need of midface advancements. Most were rather complex cases with several previous craniofacial surgeries (mean 4.4 times, range 1-8). The Modular Internal Distraction System (Howmedica Leibinger, Inc., Rutherford, NJ) was used for the gradual Le Fort III advancements. The average midface advancement obtained was 23 mm (range 15-30 mm), resulting in improved facial profile, normalized or improved dental occlusion, reduced exophthalmos, and cessation or a significant decrease in preoperative respiratory problems. The mean length of operation was 354 minutes (range 300-535 minutes), and the mean amount of perioperative blood transfusion needed was 1251 mL (range 450-1800 mL) or 46.0 mL/kg (range 8.2-121.4 mL/kg). Complications included subcutaneous infections inferolaterally to the eye (N = 3) and forehead (N = 1). One patient had worsening of her facial profile and underwent a subsequent fronto-orbital advancement. One patient developed a deviation of the nasal septum and needed a corrective rhinoplasty. One patient developed marked trismus and one needed reoperation and trimming of the anchoring titanium plate on the malar process. In one patient, the lacrimal sac was lacerated, leading to transient epiphora. In most patients, Le Fort III distraction led to a significant improvement in the facial profile. However, surgery is still a major undertaking, with several potential complications. In our hands, the rate of complications is not less than for monobloc advancement. Thus, the choice of operation method is not based on which method is the least risky but on which is best suited for the individual patient.

The management of the hypoplastic midface in syndromic craniosynostosis remains a great challenge. Frequently, patients have to be operated on numerous times to achieve a satisfactory end result, partially because of the limited skeletal advancement possible when using traditional surgical techniques. During the last decade, however, methods for gradual midfacial distraction have been presented, whereby greater advancements can be obtained. We present four children aged 17 months to 15 years with severe syndromal craniosynostosis in need of midface advancements because of severe respiratory obstruction or severe exophthalmos. These patients were complex cases with several previous craniofacial surgeries (mean of three times, range of two to six times) that yielded insufficient skeletal advancements. They were operated on with gradual monobloc advancements using the Modular Internal Distraction System. The mean length of operations was 370 minutes (range 240–455 minutes), and the mean amount of perioperative blood transfusion needed was 1,300 ml (range 280–2,700 ml) or 66.9 ml/kg (range 31.1–94.9 ml/kg). The patient with the greatest number of previous operations also had the longest operation time as well as the most blood loss. The average midface advancement obtained was 25 mm (range 20–30 mm), resulting in cessation or a significant decrease of preoperative respiratory problems, reduced exophthalmos, and improved facial profile. Apart from a local infection in one patient with a connective tissue disorder and several previous wound infections, no major postoperative complications were recorded. Distraction osteogenesis has become a versatile and safe technique that allows for large advancements of the midface.

Background: Alterations in mouth temperature may lead to changes in the force exerted by an activated superelastic wire. It has been assumed that variations in archwire stiffness associated with short-term cooling or heating are transient. This investigation studied the effect of short-term cooling or heating on the bending force exerted by nickel-titanium archwire. Material and methods: Six rectangular superelastic wires and one conventional nickel-titanium wire were tested in bending at 37oC. The test specimens were deflected 0.5 mm, and the bending force was measured continually. The activated specimens were subjected to cold (10oC) or hot (80oC) water under constant deflection, simulating an inserted archwire that is subjected to cold or hot drinks or food during a meal. Results: The conventional nickel-titanium wire was marginally affected by brief cooling or heating. In contrast, some of the superelastic wires were strongly affected by short-time application of cold or hot water. Whereas the effect of brief heating disappeared quickly, some wires continued to exert sub-baseline bending forces (up to 32% less) after short-time application of cold water and showed little or no tendencies toward increase even after 30 minutes of postexposure restitution (up to 43% less). Conclusions: Short-term exposures to hot liquid increased the bending force exerted for a given deflection transiently. The effect of short-term exposures to cold liquid was not always transient; the bending force remained sub-baseline for a number of the thermosensitive wires tested for a prolonged time.(Am J Orthod Dentofacial Orthop 1998;114:503-9)

Complex combinations of linear forces, moments, and couples are developed by the arch wire during orthodontic treatment. For instance, application of torque to a canine during distal driving may create force interactions if the tooth tips distally toward the extraction site. This investigation studied the effect of second-order couples and bracket angulations on the application of torque to a single tooth. By using a test apparatus to simulate application of torque to a single tooth, 0.016 × 0.022 inch stainless steel wires were tested in longitudinal torsion simultaneous to fixed amounts of second-order couples or fixed degrees of second-order bracket angulation. Application of a second-order couple through a bracket to a longitudinally twisted arch wire produces a third-order couple, since the bracket slot walls exert forces on the wire, tending to detwist it. This third-order couple will usually be small as the distance between the two couple members is short. Nevertheless, it may have a restraining effect on the third-order wire-bracket interaction. The results show that application of second-order couples or bracket angulations lead to an increase in exerted torque for angles of twist below 22°. Because of torsional play, a wire twisted 18° in a 0.018-inch bracket slot did not exert any torque unless it was subjected to a second-order couple. Thus, in an in vivo situation where forces interact, the actual torsional play may be substantially less than predicted from theoretical models only regarding third-order mechanics. The restraining effect of second-order couples tapered when the torque created by longitudinal twisting became much larger than the torque exerted by the second-order couple. Second-order couples of biologically acceptable magnitudes had little effect on the level of torque after the third-order clearance had been eliminated. (Am J Orthod Dentofacial Orthop 1998;113:256-62.)

Twenty-five rectangular superelastic or conventional work-hardened nickel-titanium alloy wires, commonly used in the 0.018-inch edgewise technique, supplied by seven different manufacturers, along with one braided nickel-titanium and two beta-titanium wires, were studied with respect to wire dimensions, edge bevel, and mechanical properties in longitudinal torsion at 37° C. The wires were twisted 25° and studied in deactivation, simulating application of torque to an individual tooth. Standard Siamese brackets. with stated slot heights of 0.018 inches and measured slot heights of 0.0187 inches, were used. Most wires were within ±0.0005 inches of the stated dimensions, but had more edge bevel than previously reported for stainless steel and chrome-cobalt alloy wires. Variations in wire dimensions and edge bevel led to variable torsional (third-order) clearance. The torsional stiffness varied among manufacturers within the various wire sizes, this being the result of differences in actual cross-sectional geometry and material properties. None of the tested wires exhibited superelastic properties under the current conditions, and only one wire had a superelastic tendency.(Am J Orthod Dentofacial Orthop 1998;113:57)

For more than 35 years, growth hormone (GH) has been used to promote linear growth in GH-deficient children. Previously, GH replacement in adults was limited to the supply of human pituitary-derived GH. In addition, until recently, GH replacement was not deemed clinically indicated. With the introduction of recombinant human prion-free GH, replacement therapy in GH-deficient adults has become feasible, and its use has burgeoned. In this review, recent studies on GH therapy in healthy and GH-deficient adults are evaluated to provide a rational basis for the widened scope of its clinical application.

Cavernous hemangiomas of the orbit are low-pressure vascular tumors. Usually benign, they become symptomatic by the local mass effect, pushing the eyeball forward, causing exophthalmia, by oculomotor muscle and nerve compression causing diplopia or by optic nerve compression, leading to visual impairment.  Radiotherapy is of limited value in their treatment because of the fragility of the optic nerve and subsequent blindness risk. Surgery remains the gold standard and definitive treatment. We illustrate in this video a transpalpebral superolateral orbitotomy and extirpation of an orbital cavernous hemangioma.  A 52-yr-old healthy woman was sent for neurosurgical consultation by her ophthalmologist. She described a history of progressive unilateral right exophthalmia in the last months. A cerebral magnetic resonance imaging (MRI) revealed a 2.5-cm-large orbital lesion located superiorly and laterally to the eyeball. Surgery was proposed and accepted by the patient. The frontozygomatic component of the orbital rim needed to be removed to safely extirpate the cavernous hemangioma without exerting unnecessary and risky pressure on the eyeball.1,2 We decided to go for a superolateral orbitotomy via a transpalpebral incision.3 Total removal of the lesion was achieved with no complication. Exophthalmia normalized.  Written patient consent was obtained for use and publication of their image after complete information. The patient consented to the surgery.