Paragangliomas Arising From the Laryngeal Paraganglia: Thyroid and Laryngeal Paragangliomas With Radiology-Pathology Correlation.

Paragangliomas are neuroendocrine tumors that arise from the embryonic neural crest cells of the extra-adrenal chromaffin and non-chromaffin cellular system. Paragangliomas arising from the laryngeal paraganglia, which occur in the thyroid and larynx, are a rare subset of paragangliomas compared to the more common locations of the carotid body, vagale, jugular, and tympanic paragangliomas. The preoperative diagnosis of both thyroid and laryngeal paragangliomas may pose a challenge due to cytological, pathological, and imaging non-specificity that overlaps with many other neoplasms. These lesions may be associated with significant intraoperative bleeding and complicated excision with adherence to nearby structures, including the recurrent laryngeal nerve. This article discusses the imaging appearance, pathological features, clinical and operative considerations and manifestations, and management of head and neck paragangliomas, as seen in two patients at our institution.

Case report: Side-firing intraoperative ultrasound guided endoscopic endonasal resection of a clival chordoma.

Clival chordomas are locally invasive midline skull base tumors arising from remnants of the primitive notochord. Intracranial vasculature and cranial nerve involvement of tumors in the paraclival region necessitates image guidance that provides accurate real-time feedback during resection. Several intraoperative image guidance modalities have been introduced as adjuncts to endoscopic endonasal surgery, including stereotactic neuronavigation, intraoperative ultrasound, intraoperative MRI, and intraoperative CT. Gross total resection of chordomas is associated with a lower recurrence rate; therefore, intraoperative imaging may improve long-term outcomes by enhancing the extent of resection. However, among these options, effectiveness and accessibility vary between institutions. We previously published the first use of an end-firing probe in the resection of a clival chordoma. End-firing probes provide a single field of view, primarily limited to depth estimation. In this case report, we discuss the benefits of employing a novel minimally invasive side-firing ultrasound probe as a cost-effective and time-efficient option to navigate the anatomy of the paraclival region and guide endoscopic endonasal resection of a large complex clival chordoma.

A deceptive mass on neonatal ultrasound and a fetal brain MRI-confirmed complex dural arteriovenous fistula postnatally: illustrative case.

BACKGROUND: Dural arteriovenous fistulas (dAVFs) are direct, aberrant connections between dural arteries and cerebral veins. In neonates, delayed diagnosis results in grim outcomes. Treatment involves endovascular management because of its success and tolerability. Here, the authors present a case of a complex dAVF initially recognized with an in utero neurosonogram and fetal magnetic resonance imaging (MRI). OBSERVATIONS: A 21-week fetal ultrasound of a nonspecific brain mass was confirmed with fetal MRI as a 2.7-cm T1-hyperintense posterior fossa mass. Although a large flow void in the left middle cranial fossa was present, postnatal computed tomography angiography ultimately revealed a high-flow dAVF communicating with the left transverse sinus. In the early postnatal period, the patient developed hydrocephalus. After successful partial embolization, 6-week postangiogram brain MRI indicated disease progression with the development of a venous varix causing brainstem compression. Repeat embolization resulted in complete cessation of early venous drainage. LESSONS: Neonatal dAVFs are exceedingly rare and result in futile outcomes; however, detection in utero is possible. Although definitive therapy must be performed postnatally, constant monitoring and early delivery can prevent complications. Attention to fetal ultrasound is essential, and knowledge of fetal MRI in the detection of these complex lesions can significantly improve outcomes.

A case of head and neck cutaneous squamous cell carcinoma highlighting aggressive perineural features.

Cutaneous squamous cell carcinoma (cSCC) is the second most common nonmelanoma skin cancer in the United States following basal cell carcinoma. The majority are successfully cured by surgical excision or Mohs microsurgery. A subset of cSCCs are more aggressive and likely to recur locally, spread to regional lymph nodes or even distantly, and can even result in death. High-risk features of cSCC including perineural invasion of nerve >0.1 mm in diameter and invasion beyond the subcutaneous fat are not routinely reported by Mohs microsurgery. Facial cSCC commonly involves branches of the facial nerve (VII) or trigeminal nerve (V). Clinical symptoms associated with cranial nerve VII and V involvement include pain, paresthesia of the face and tongue, facial paralysis. Assessment of nerve involvement by magnetic resonance imaging (MRI) is the most optimal imaging modality. Here, we present a case where Mohs microsurgery was performed on a facial cSCC 1.5 years prior to the development of facial paresis. We aim to highlight the interesting perineural path resulting in facial paralysis and associated symptomatology, the importance of MRI, and to remind clinicians of important high-risk features of cSCC.

Fear the reaper: reversible cerebrovascular vasoconstriction syndrome after hot pepper ingestion.

The Carolina Reaper pepper is one of the spiciest edible peppers in the world. While localized symptoms such as mouth burning, mouth numbness, and even vomiting are the main risks of eating these peppers, recent case reports have revealed more serious complications of these potent foods. A 15-year-old healthy male ingested a Carolina Reaper pepper on a dare. Two days later, he developed an acute headache during football practice and was subsequently diagnosed with an acute cerebellar infarct and reversible cerebrovascular vasoconstriction syndrome. Reversible cerebral vasoconstriction syndrome should be considered in patients who present with severe headache after ingestion of ultraspicy peppers, and early treatment of reversible cerebral vasoconstriction syndrome should be initiated in patients with severe headache after pepper ingestion.

Wandering spleen with splenic torsion in a child with DiGeorge syndrome.

Wandering spleen is a rare condition, occurring due to either abnormal development of or abnormal laxity of suspensory ligaments. The hypermobility of the spleen predisposes these patients to splenic torsion, which may be a life-threatening complication. The clinical presentation of wandering spleen varies widely from vague pain to an acute abdomen. There are numerous case reports of other congenital anomalies in children with a wandering spleen. We present a case of wandering spleen with splenic torsion in a child with DiGeorge syndrome, which to our knowledge has not been previously reported.

The Synthesis of Trifluoromethyl-sulfonimidamides from Sulfinamides.

A general synthesis of CF3-sulfonimidamides from sulfinamides under both batch and continuous flow conditions is described. The reaction proceeds via a sulfonimidoyl fluoride intermediate. A reaction scope showing good group variation on the substituents of both nitrogen atoms is also presented.

An unusual cause of acute headache: subarachnoid free air secondary to spontaneous bronchopleurodurosubarachnoid fistula from a Pancoast tumor.

Pneumocephalus and pneumorrhachis are related to transgression of the barriers to the central nervous system. We present a patient with a Pancoast tumor treated with palliative chemoradiation who developed symptomatic spinal and intracranial air caused by spontaneous bronchopleurodurosubarachnoid fistula secondary to direct tumor invasion into the thecal sac.

Palladium-catalysed aminosulfonylation of aryl-, alkenyl- and heteroaryl halides: scope of the three-component synthesis of N-aminosulfonamides.

By using DABCO·(SO(2))(2), DABSO, as a solid bench-stable SO(2)-equivalent, the palladium-catalysed aminosulfonylation of aryl-, alkenyl- and heteroaryl halides has been achieved. N,N-Dialkylhydrazines are employed as the N-nucleophiles and provide N-aminosulfonamides as the products in good to excellent yields. The reactions are operationally simple to perform, requiring only a slight excess of SO(2) (1.2-2.2 equiv.), and tolerate a variety of substituents on the halide coupling partner. Variation of the hydrazine component is also demonstrated. The use of N,N-dibenzylhydrazine as the N-nucleophile delivers N-aminosulfonamide products that can be converted into the corresponding primary sulfonamides using a high-yielding, telescoped, deprotection sequence. The ability to employ hydrazine·SO(2) complexes as both the N-nucleophile and SO(2) source is also illustrated.

Distribution of hand location in monkeys during spontaneous behavior.

Recently it was shown that electrical stimulation of the precentral gyrus of monkeys can evoke complex, coordinated movements. In the forelimb representation, stimulation of each site caused the arm to move to a specific final posture, and thus the hand to move to a location in space. Among these stimulation-evoked hand locations, certain regions of the hand's workspace were more represented than others. We hypothesized that a similar non-uniform distribution of hand location should be present during a monkey's spontaneous behavior. The present study examined the distribution of hand location of monkeys in their home cages. This distribution was similar to that found by stimulation of the precentral gyrus. That is, arm postures that were over-represented in spontaneous behavior were also over-represented in the movements evoked by cortical stimulation.

Mapping from motor cortex to biceps and triceps altered by elbow angle.

This experiment used cortical microstimulation to probe the mapping from primary motor cortex to the biceps and triceps muscles of the arm in monkeys. The mapping appeared to change depending on the angle at which the elbow was fixed. For sites in the dorsal part of the arm and hand representation, the effects of stimulation were consistent with initiating a movement of the elbow to an extended angle. Stimulation evoked more triceps activity than biceps activity, and this difference was largest when the elbow was fixed in a flexed angle. For sites in the ventral part of the arm and hand representation, stimulation had the opposite effect, consistent with initiating a movement of the elbow to a flexed angle. For these sites, stimulation evoked more biceps activity than triceps activity, and the difference was largest when the elbow was fixed in an extended angle. For sites located in intermediate positions, stimulation evoked an intermediate effect consistent with initiating a movement of the elbow to a middle, partially flexed angle. For these sites, when the elbow was fixed at a flexed angle, the evoked activity was largest in the triceps, and when the elbow was fixed at an extended angle, the evoked activity was largest in the biceps. These effects were obtained with 400-ms-long trains of biphasic pulses presented at 200 Hz and 30 microA. They were also obtained by averaging the effects of individual, 30-microA pulses presented at 15 Hz. How this stimulation-evoked topography relates to the normal function of motor cortex is not yet clear. One hypothesis is that these results reflect a cortical map of desired joint angle.

Twitches versus movements: a story of motor cortex.

Modern study of the neurophysiology of the cerebral cortex began with Fritsch and Hitzig's discovery that electrical stimulation of the cortex produces movements. The importance of this discovery was threefold: it was the first demonstration of cortex devoted to motor function, the first indication that the cortex was electrically excitable, and the first evidence of a topographically organized representation in the brain. Fritsch and Hitzig's basic findings were soon replicated by Ferrier, but there were differences between the two studies in both method and interpretation. These different approaches have continued to reverberate in research on the function of motor cortex from the late 19th century to the present day.

Complex movements evoked by microstimulation of the ventral intraparietal area.

Most neurons in the ventral intraparietal area (VIP) of the macaque brain respond to both visual and tactile stimuli. The tactile receptive field is usually on the face, and the visual receptive field usually corresponds spatially to the tactile receptive field. In this study, electrical microstimulation of VIP, but not of surrounding tissue, caused a constellation of movements including eye closure, facial grimacing, head withdrawal, elevation of the shoulder, and movements of the hand to the space beside the head or shoulder. A similar set of movements was evoked by an air puff to the monkey's cheek. One interpretation is that VIP contributes to defensive movements triggered by stimuli on or near the head.

The cortical control of movement revisited.

Recently, we found that electrical stimulation of motor cortex caused monkeys to make coordinated, complex movements. These evoked movements were arranged across the cortex in a map of spatial locations to which the hand moved. We suggest that some of the subdivisions previously described within primary motor and premotor cortex may represent different types of actions that monkeys tend to make in different regions of space. According to this view, primary and premotor cortex may fit together into a larger map of manual space.

Complex movements evoked by microstimulation of precentral cortex.

Electrical microstimulation was used to study primary motor and premotor cortex in monkeys. Each stimulation train was 500 ms in duration, approximating the time scale of normal reaching and grasping movements and the time scale of the neuronal activity that normally accompanies movement. This stimulation on a behaviorally relevant time scale evoked coordinated, complex postures that involved many joints. For example, stimulation of one site caused the mouth to open and also caused the hand to shape into a grip posture and move to the mouth. Stimulation of this site always drove the joints toward this final posture, regardless of the direction of movement required to reach the posture. Stimulation of other cortical sites evoked different postures. Postures that involved the arm were arranged across cortex to form a map of hand positions around the body. This stimulation-evoked map encompassed both primary motor and the adjacent premotor cortex. We suggest that these regions fit together into a single map of the workspace around the body.