Classic signs in head and neck imaging.

Radiologists have long relied upon the use of metaphoric imaging signs to attribute meaning to disease or anatomy-specific imaging patterns encountered in clinical imaging. Teachers of radiology often employ the use of such signs to help learners rapidly identify the typical appearance of various pathologies. Head and neck (H&N) imaging is no exception, and as a specialty that deals with uncommon pathologies and complex anatomy, learners and practising radiologists alike may benefit from this simplistic, pattern-based approach. In this review, we present a compendium of classic imaging signs of H&N lesions, including signs related to traumatic, infectious, neoplastic, congenital, and inflammatory aetiologies found throughout the spectrum of H&N sites (temporal bones, orbits, paranasal sinuses, larynx, salivary glands, and neck soft tissues). Additionally, we identify potential pitfalls and detail critical clinical ramifications related to the rapid and accurate diagnosis of these pathologies.

Management of sword-swallower injuries.

OBJECTIVE: To report an unusual case of hypopharyngeal perforation in a sword-swallower, with emphasis on management options. METHOD: Case report and review of the English language literature concerning sword-swallowing injuries to the hypopharynx and oesophagus. RESULTS: A 29-year-old male sword-swallower suffered hypopharyngeal perforation during a performance. The patient received conservative management, with intensive care unit admission, infectious disease consultation, intravenous antibiotics, discontinuation of oral intake and close observation. He progressed well, resumed oral intake on hospital day six, and was discharged home on hospital day eight. CONCLUSION: Sword-swallowing is an unusual vocation which may lead to potentially devastating injuries. This case report and review of the literature illustrates the management options for such hypopharyngeal and oesophageal injuries.

Intra-osseous meningioma of the orbit: an unusual presentation (2007: 5b).

Primary calvarial or intra-osseous meningiomas are uncommon lesions often confused preoperatively with other primary or secondary bone tumors of the skull. We present details of a patient with a primary calvarial meningioma involving the frontal, zygomatic, sphenoid and temporal bones that was radiographically diagnosed as fibrous dysplasia and initially treated conservatively for many years. Progressive vision loss and significant proptosis, with difficulty of eye closure, prompted surgical removal with cranioplasty and a 3D reconstructed prosthetic flap. Histological examination revealed intra-osseous meningioma. The clinical and radiological findings of intra-osseous meningiomas are discussed, together with a review of the literature.

BOLD fMRI activation induced by vagus nerve stimulation in seizure patients.

OBJECTIVE: To identify the cerebral activated regions associated with the vagus nerve stimulation in epilepsy patients. DESIGN: Blood oxygenation level dependent functional magnetic resonance imaging (BOLD fMRI) was employed to detect areas of the brain activated by vagus nerve stimulation in five patients with documented complex partial seizures. METHODS: Functional MRI was done on a GE 1.5T Echospeed horizon scanner. Before each patient entered the scanner, the vagal nerve stimulator was set to a specific ON-OFF paradigm so that the data could be analysed using a box-car type of design. The brains were scanned both anatomically and functionally. The functional images were corrected for head motion and co-registered to the anatomical images. Maps of the activated areas were generated and analysed using the brain mapping software, SPM99. The threshold for activation was chosen as p < 0.001. RESULTS: All patients showed activation in the frontal and occipital lobes. However, activation in the thalamus was seen only in the two patients with improved seizure control. CONCLUSIONS: BOLD fMRI can detect activation associated with vagus nerve stimulation. There may be a relation between thalamic activation and a favourable clinical outcome.

Parallel cortical networks for volitional control of swallowing in humans.

A number of studies have demonstrated the involvement of parallel networks in the control of voluntary sequential motor procedures. We sought to determine whether a parallel network organization may be found for complex, sequentially based motor systems that are the product of both voluntary and automatic control processes. Specifically, we sought to determine whether the cortical organizational scheme for voluntary repetitive swallowing in adult humans is characterized by a hierarchical dual-projection model or by modules organized into parallel systems. We utilized functional magnetic resonance imaging (fMRI) to investigate cortical function during normal swallowing tasks in eight healthy human adults. Subjects performed both dry (saliva) and bolus (3 ml/bolus of water) swallows. Activation during swallowing tasks localized to sensorimotor areas (M1, S1, and SMA), S2, premotor cortex, posterior parietal cortex, cingulate gyrus, inferior frontal gyrus, the cerebellum, the insular cortex, auditory cortex, corpus callosum, and the basal ganglia and thalamus. Principal components analysis (PCA) of these regions revealed five functional clusters or modules: (1) sensorimotor areas and cingulate gyrus; (2) inferior frontal gyrus, S2, corpus callosum, basal ganglia and thalamus; (3) premotor cortex and posterior parietal cortex; (4) cerebellum; and (5) insula. Analysis of the functional relationship between these areas demonstrated two parallel loops defined by connections to either the cerebellum or insula and connected through the sensorimotor-cingulate module. Path analysis was performed to test the hypothesis of modules organized into parallel loops versus a hierarchical dual-projection model consisting of two separate, singular hierarchical serial pathways from the sensorimotor cortex or insula to the thalamus. These results support the model of modules organized into parallel loops (P=0.8), but not the hierarchical dual-projection model (P<0.0001). Organization of the control of voluntary repetitive swallowing into two parallel systems may confer the ability to effectively coordinate and integrate this highly complex sequentially based motor behavior.

Neural control of tongue movement with respect to respiration and swallowing.

The tongue must move with remarkable speed and precision between multiple orofacial motor behaviors that are executed virtually simultaneously. Our present understanding of these highly integrated relationships has been limited by their complexity. Recent research indicates that the tongue s contribution to complex orofacial movements is much greater than previously thought. The purpose of this paper is to review the neural control of tongue movement and relate it to complex orofacial behaviors. Particular attention will be given to the interaction of tongue movement with respiration and swallowing, because the morbidity and mortality associated with these relationships make this a primary focus of many current investigations. This review will begin with a discussion of peripheral tongue muscle and nerve physiology that will include new data on tongue contractile properties. Other relevant peripheral oral cavity and oropharyngeal neurophysiology will also be discussed. Much of the review will focus on brainstem control of tongue movement and modulation by neurons that control swallowing and respiration, because it is in the brainstem that orofacial motor behaviors sort themselves out from their common peripheral structures. There is abundant evidence indicating that the neural control of protrusive tongue movement by motoneurons in the ventral hypoglossal nucleus is modulated by respiratory neurons that control inspiratory drive. Yet, little is known of hypoglossal motoneuron modulation by neurons controlling swallowing or other complex movements. There is evidence, however, suggesting that functional segregation of respiration and swallowing within the brainstem is reflected in somatotopy within the hypoglossal nucleus. Also, subtle changes in the neural control of tongue movement may signal the transition between respiration and swallowing. The final section of this review will focus on the cortical integration of tongue movement with complex orofacial movements. This section will conclude with a discussion of the functional and clinical significance of cortical control with respect to recent advances in our understanding of the peripheral and brainstem physiology of tongue movement.

Parameters of radiologic care: An official report of the American Academy of Oral and Maxillofacial Radiology.

The American Academy of Oral and Maxillofacial Radiology developed these Parameters of Care to provide national guidelines for the use of radiographs prescribed for the diagnosis of disease, treatment planning, and follow-up care of patients with abnormalities of the oral and maxillofacial region. The Parameters cover radiographic techniques, imaging of the temporomandibular joint, imaging of diseases of the jaws, and imaging of dental implant sites.

Automation bias and errors: are crews better than individuals?

The availability of automated decision aids can sometimes feed into the general human tendency to travel the road of least cognitive effort. Is this tendency toward "automation bias" (the use of automation as a heuristic replacement for vigilant information seeking and processing) ameliorated when more than one decision maker is monitoring system events? This study examined automation bias in two-person crews versus solo performers under varying instruction conditions. Training that focused on automation bias and associated errors successfully reduced commission, but not omission, errors. Teams and solo performers were equally likely to fail to respond to system irregularities or events when automated devices failed to indicate them, and to incorrectly follow automated directives when the contradicted other system information.

Lateralization of cortical function in swallowing: a functional MR imaging study.

BACKGROUND AND PURPOSE: While functional MR imaging and other techniques have contributed to our knowledge of functional brain localization, these methods have not been extensively applied to the complex and incompletely understood task of swallowing. We used functional MR imaging to investigate motor cortex activity during swallowing in healthy human adults. METHODS: Eight subjects were imaged on a 1.5-T MR system using blood oxygen level-dependent contrast mechanisms. Subjects performed three swallowing tasks and a finger-tapping task. Areas of activation in the cortex and subcortical areas were tabulated, and a laterality index, defined as LI = [sigmas left - sigmas right]/[sigmas left + sigmas right] x 100, was computed for the three tasks. RESULTS: Activation was observed in the primary motor and sensory cortices, motor processing and association areas, and subcortical sites. This activity was dominant for one hemisphere with left hemispheric dominance more prevalent among the subjects. Right hemispheric dominance, however, showed stronger lateralization than the left hemisphere. CONCLUSION: Our data indicate that specific sites in the motor cortex and other cortical and subcortical areas are activated with swallowing tasks and that hemispheric dominance is a feature of swallowing under these conditions. In addition, we demonstrate the utility of functional MR imaging in the study of the cortical representation of swallowing and suggest a role for functional MR imaging in the diagnosis of dysphagia of cerebral origin.

Cortical representation of swallowing in normal adults: functional implications.

OBJECTIVE: Dysphagia of neurogenic or postsurgical origin presents management and therapeutic challenges to the otolaryngologist. Improvements in management and therapeutic approaches may be facilitated by understanding how the central nervous system controls swallowing. The purpose of this investigation was to utilize functional magnetic resonance imaging to determine patterns of cortical activity during swallowing in normal, healthy adult subjects. STUDY DESIGN: Functional magnetic resonance imaging (fMRI) was performed on eight healthy adult subjects using conventional BOLD (blood oxygenation level dependent) techniques. METHODS: Subjects performed three different swallowing tasks including dry and bolus swallows, and performed a control finger movement task. Statistical maps of cortical activation were generated using a cross-correlation analysis. One-way and two-way ANOVA statistical analyses were performed to compare activated areas among the different tasks and to determine the effects of task sequence. RESULTS: Activation during the three swallowing tasks occurred in the primary motor cortex, primary somatosensory cortex, and other cortical and subcortical sites. Cortical representation of swallowing and finger movement followed somatotopic maps. Differential distribution of cortical activation was observed for the different swallowing tasks. CONCLUSIONS: Activation of the primary motor and somatosensory cortices, as well as other sensory-motor areas, occurs with swallowing in normal adults. Differential distribution of cortical activity with different swallowing tasks suggests differential functional organization for different swallowing tasks. Understanding these mechanisms may facilitate improved management and therapeutic intervention for neurogenic and postsurgical dysphagia.

Dosimetry and cost of imaging osseointegrated implants with film-based and computed tomography.

Thermoluminescent dosimeters were used to measure radiation doses at craniofacial sites in a tissue-equivalent phantom during film-based multidirectional tomography with the Tomax Ultrascan (Incubation Industries, Ivyland, Pa.) and during computed tomography with the Elscint Excel 2400 (Elscint Corp., Tel Aviv, Israel). Mean absorbed doses for presurgical mandibular and maxillary canine and molar implant assessments were converted to equivalent doses, which were then multiplied by published weighting factors and summed to give effective doses. The computed tomography device consistently delivered higher doses than the Tomax Ultrascan to all anatomic locations; the differences were most pronounced when only one or two implant sites were evaluated. The reasons for the dose disparities are considered both anatomically and procedurally. A survey of examination cost revealed film-based multidirectional tomography to be less expensive than computed tomography.

Automation bias: decision making and performance in high-tech cockpits.

Automated aids and decision support tools are rapidly becoming indispensable tools in high-technology cockpits and are assuming increasing control of"cognitive" flight tasks, such as calculating fuel-efficient routes, navigating, or detecting and diagnosing system malfunctions and abnormalities. This study was designed to investigate automation bias, a recently documented factor in the use of automated aids and decision support systems. The term refers to omission and commission errors resulting from the use of automated cues as a heuristic replacement for vigilant information seeking and processing. Glass-cockpit pilots flew flight scenarios involving automation events or opportunities for automation-related omission and commission errors. Although experimentally manipulated accountability demands did not significantly impact performance, post hoc analyses revealed that those pilots who reported an internalized perception of "accountability" for their performance and strategies of interaction with the automation were significantly more likely to double-check automated functioning against other cues and less likely to commit errors than those who did not share this perception. Pilots were also lilkely to erroneously "remember" the presence of expected cues when describing their decision-making processes.

The effects of theophylline on metabolic rate in chronic obstructive lung disease patients.

OBJECTIVE: To study the effect of theophylline and an alternative bronchodilator, ipratropium, on resting energy expenditure (REE) and thermic effect of food (TEF). DESIGN: 5-week randomized, repeated measures, double-blind, cross-over design, comparing the effects of theophylline and ipratropium drug treatments on metabolic measurements made during a baseline period. SETTING: Ambulatory Clinical Trials Center at University of California, San Diego. SUBJECTS: 14 patients at least 65 years old with a clinical diagnosis of chronic obstructive pulmonary disease. MEASUREMENTS: Resting energy expenditure and thermic effect of food were measured by indirect calorimetry. Body composition was determined using bioimpedance. RESULTS: Resting energy expenditure did not differ between baseline and either of the two drug treatments. In men, the thermic effect of food increased significantly during theophylline and ipratropium drug treatment periods (p < 0.03). CONCLUSIONS: Theophylline or ipratropium does not appear to increase resting energy expenditure in patients with chronic obstructive lung disease. The elevated values for thermic effect of food in men need further study.

Coordination of oral cavity and laryngeal movements during swallowing.

In this study, dynamic imaging was used to track the movements of oral cavity and laryngeal structures during swallowing in 10 normal adults subjects. The movements of tiny lead pellet markers attached to the lips, tongue, mandible, and soft palate, as well as anatomic landmarks on the hyoid bone, were measured in relation to a reference pellet affixed to the upper central incisors. Sagittal views of the oral cavity were obtained using standard videofluorography. Each subject produced 10 swallows of 12 ml of tap water followed by 5 swallows with a bite block placed between the molars. The recorded video images were input to a microcomputer where the x- and y-coordinates of the pellets were measured. Results of the analyses revealed considerable temporal overlap in the timing of oral cavity and laryngeal movements, widespread individual variability in coordination patterns and movement trajectories, and selective effects of the bite block. These data suggest the existence of individual adaptive strategies in the programming and control of swallowing movements.

Postextraction osteomyelitis in a bone marrow transplant recipient.

This report describes a case of mandibular osteomyelitis after a dental extraction in a patient who subsequently underwent bone marrow transplantation (BMT) for lymphoblastic lymphoma. Surgical guidelines consistent with National Cancer Institute recommendations were followed for the extraction, which was performed before initiation of the myelosuppressive conditioning regimen. However, moderate tenderness developed at the extraction site beginning 10 days after marrow infusion. On day 26 the patient became febrile and blood culture-positive for Staphylococcus epidermidis. Radiographs exposed on day 28 demonstrated changes consistent with low-grade osteomyelitis, including diffuse loss of lamina dura and an irregular osseous rarefaction extending 1 cm posterior to the extraction site. Although the indwelling Hickman catheter was the presumed source for bacteremia, clinical and radiographic data led to consideration of mandibular osteomyelitis as an alternative cause. Characteristics of this infection in BMT recipients are reviewed. Recommendations for dental extractions and prophylactic antibiotic regimens for catheterized BMT recipients are also discussed. Although mandibular osteomyelitic lesions are not common in profoundly immunosuppressed BMT recipients, prompt recognition and treatment are essential when the disease occurs.

Work in the family and employing organization.

Issues involved in the attempts to balance roles in employing organizations and family organizations are discussed. The literature on the causal links between work and family relationships, the variables used in such studies, and the models used to describe the findings are presented. Because attempts to balance the roles in the two environments can lead to conflict and stress, organizations have responded with programs such as maternity and parental leave, child and dependent care, alternative work schedules and work stations, and employee assistance and relocation programs. These programs are reviewed with particular emphasis on their benefits and costs.