Margo McKenna Benoit

Primary and multisensory cortical activity is correlated with audiovisual percepts

Incongruent auditory and visual stimuli can elicit audiovisual illusions such as the McGurk effect where visual /ka/ and auditory /pa/ fuse into another percept such as/ta/. In the present study, human brain activity was measured with adaptation functional magnetic resonance imaging to investigate which brain areas support such audiovisual illusions. Subjects viewed trains of four movies beginning with three congruent /pa/ stimuli to induce adaptation. The fourth stimulus could be (i) another congruent /pa/, (ii) a congruent /ka/, (iii) an incongruent stimulus that evokes the McGurk effect in susceptible individuals (lips /ka/ voice /pa/), or (iv) the converse combination that does not cause the McGurk effect (lips /pa/ voice/ ka/). This paradigm was predicted to show increased release from adaptation (i.e. stronger brain activation) when the fourth movie and the related percept was increasingly different from the three previous movies. A stimulus change in either the auditory or the visual stimulus from /pa/ to /ka/ (iii, iv) produced within‐modality and cross‐modal responses in primary auditory and visual areas. A greater release from adaptation was observed for incongruent non‐McGurk (iv) compared to incongruent McGurk (iii) trials. A network including the primary auditory and visual cortices, nonprimary auditory cortex, and several multisensory areas (superior temporal sulcus, intraparietal sulcus, insula, and pre‐central cortex) showed a correlation between perceiving the McGurk effect and the fMRI signal, suggesting that these areas support the audiovisual illusion. Hum Brain Mapp, 2010.

Facial nerve hemangiomas: vascular tumors or malformations?

OBJECTIVE: To reclassify facial nerve hemangiomas in the context of presently accepted vascular lesion nomenclature by examining histology and immunohistochemical markers. STUDY DESIGN: Cohort analysis of patients diagnosed with a facial nerve hemangioma between 1990 and 2008. SETTING: Collaborative analysis at a specialty hospital and a major academic hospital. SUBJECTS AND METHODS: Seven subjects were identified on composite review of office charts, a pathology database spanning both institutions, and an encrypted patient registry. Clinical data were compiled, and hematoxylin-eosin–stained specimens were reviewed. For six patients, archived pathological tissue was available for immunohistochemical evaluation of markers specific for infantile hemangioma (glucose transporter protein isoform 1 [GLUT1] and Lewis Y antigen) and for lymphatic endothelial cells (podoplanin). RESULTS: All patients clinically presented with slowly progressive facial weakness at a mean age of 45 years without prior symptomatology. Hemotoxylin-eosin–stained histopathological slides showed irregularly shaped, dilated lesional vessels with flattened endothelial cells, scant smooth muscle, and no internal elastic lamina. Both podoplanin staining for lymphatic endothelial cells and GLUT1 and LewisY antigen staining for infantile hemangioma endothelial cells were negative in lesional vessels in all specimens for which immunohistochemical analysis was performed. CONCLUSION: Lesions of the geniculate ganglion historically referred to as “hemangiomas” do not demonstrate clinical, histopathological, or immunohistochemical features consistent with a benign vascular tumor, but instead are consistent with venous malformation. We propose that these lesions be classified as “venous vascular malformations of the facial nerve.” This nomenclature should more accurately predict clinical behavior and guide therapeutic interventions.

Cancer of the Nasal Cavity in the Pediatric Population

OBJECTIVE. The purpose of this work was to investigate the clinical manifestations and diagnostic range of malignant entities presenting as a nasal mass in the pediatric population. PATIENTS AND METHODS. A retrospective cohort analysis was conducted at a specialty hospital and a tertiary care university hospital. Patients aged between birth and 18 years and diagnosed with a malignancy that arose within the nasal cavity between the years 1991 and 2006 were included. This institution-specific patient group was compared with a similar cohort of patients extracted from the national Surveillance Epidemiology and End Results database. The main outcome measures were the incidence, presentation, and diagnoses of nasal cancer presenting in this population. RESULTS. Sixteen patients with nasal malignancies presented institutionally in the defined pediatric age group. Patient age at the time of diagnosis ranged from 7 months to 17 years, with a slight male predominance. The main presenting symptoms were unilateral nasal congestion and ophthalmologic complaints. The median time from presentation to diagnosis was 7 weeks; patients who presented with nonspecific complaints, such as nasal obstruction, headache, and fatigue, were given a diagnosis, on average, later than those who presented with focal manifestations. Nationwide, 47 patients were identified from the Surveillance Epidemiology and End Results database. In both subject groups, the most common diagnoses were rhabdomyosarcoma (37.5% institutionally and 23% in the Surveillance Epidemiology and End Results group) and esthesioneuroblastoma (25% institutionally and 28% Surveillance Epidemiology and End Results). In the Surveillance Epidemiology and End Results cohort, the overall mean survival rate was 188 months. CONCLUSIONS. Nasal cancer in the pediatric population often presents with nonspecific signs and symptoms, and a high index of suspicion is necessary for a timely diagnosis. Soft tissue sarcomas are expectedly common. The relative high frequency of esthesioneuroblastoma is particularly noteworthy.

Image guidance systems for minimally invasive sinus and skull base surgery in children

OBJECTIVE The use of image guidance for sinonasal and skull base surgery has been well-characterized in adults but there is limited information on the use of these systems in the pediatric population, despite their widespread use. The aim of this study is to evaluate the use of image guidance systems to facilitate an endoscopic minimally invasive approach to sinonasal and skull base surgery in a pediatric population. METHODS A retrospective cohort study was performed at a tertiary pediatric hospital. Thirty-three children presented with complications of sinusitis, tumors, traumatic, or congenital lesions of the skull base and underwent endoscopic surgery using image guidance from March 2000 to April 2007. Patient variables including diagnosis, extent of disease, and complications were extracted from paper and computer charts. Additional surgical variables including set-up time, accuracy, surgeon satisfaction index and number of uses per case were also reviewed. RESULTS Twenty-eight patients (85%) underwent sinonasal surgery and five (15%) underwent skull base surgery. Indications included infectious complications of acute sinusitis (N=15), neoplasms (N=12), choanal atresia (N=4), and cerebrospinal fluid leak (N=2). Thirty-one patients (94%) required only one procedure. No surgical complications were reported. Surgeon satisfaction, mean accuracy and number of uses per procedure increased over time (p<0.05). CONCLUSIONS Image guidance systems are safe and effective tools that facilitate a minimally invasive approach to sinonasal and skull base surgery in children. Consistent with adult literature, usage and surgeon comfort increased with experience. The additional anatomical information obtained by image guidance systems facilitates a minimally invasive endoscopic approach for sinonasal and skull base pathologies.

The presentation and management of mandibular tumors in the pediatric population.

To review the presentation and management of malignant tumors of the mandible in children.

Lobular capillary hemangioma of the nasal cavity in a five-year-old boy.

Afive-year-old male was referred to the pediatric otolaryngology clinic with recurrent right anterior epistaxis and unilateral nasal obstruction. There was no history of systemic disease, neurologic changes, trauma, or foreign body insertion. He had no significant medical or surgical history. Upon examination, he was noted to have an obstructing friable right intranasal mass (Fig 1). Anterior rhinoscopy was normal on the opposite side. The remainder of his head and neck examination was normal. Imaging studies revealed a lobular heterogeneous nasal mass causing mass effect on the septum and lateral nasal wall. There was no erosion or remodeling of bone, and no extension outside of the nasal cavity. No prominent feeding vessels were identified. The mass was excised endoscopically using image guidance. Intraoperatively, the mass was noted to have a single pedicle attachment to the nasal septum. Under direct visualization, the posterior septal attachment was lysed. Due to the size of the mass, it could not be extracted through the nose. It was pushed into the nasopharynx and removed transorally. The final histopathologic diagnosis was lobular capillary hemangioma. On follow-up at eight months, the patient reported resolution of his epistaxis and improved nasal breathing, and fiberoptic endoscopy revealed no evidence of recurrence. Lobular capillary hemangioma (LCH), formerly known as pyogenic granuloma, is a benign vascular lesion of the skin and mucosa. These lesions are more common in male children and in female adults during pregnancy. The head and neck are the most frequent sites of occurrence, with cutaneous or lip lesions presenting most commonly, followed by oral mucosa and nasal mucosa. LCH of the nasal mucosa can present with recurrent unilateral epistaxis and unilateral nasal obstruction or rhinorrhea. Most nasal lesions occur in Little’s area on the anterior septum, in the nasal vestibule or inferior turbinate. Repetitive trauma or manipulation has been suspected as a causative factor. LCH can evolve rapidly over the course of a few weeks but does not demonstrate the proliferative and involutional phases characteristic of classic hemangioma of infancy. Diagnosis involves a complete history and physical, with endoscopic evaluation of the nasal cavities. Imaging with CT and MRI can be useful for narrowing the differential diagnosis and defining a treatment plan. The definitive treatment is complete removal. Endoscopic excision is the preferred technique to ensure localization of the mucosal origin and to avoid facial incisions. Embolization and adjuvant therapies are unwarranted. With complete resection, recurrences are rare. This case report was deemed exempt from human studies committee review.

Adenoidal follicular T helper cells provide stronger B-cell help than those from tonsils.

The tonsils and adenoids are secondary lymphoid organs, where antigen processing and immune cell development occur to control bacterial colonization and infection in the upper respiratory tract. Both organs are abundant in follicular T helper cells (TFH), a subset of T cells specialized for promoting B‐cell development. There are no prior studies on differences between the immune cells of the tonsils and adenoids and whether the cells function differently.

Paraganglioma of the Hypoglossal Nerve

OBJECTIVES To report a case of paraganglioma arising from the hypoglossal nerve and review the anatomy, clinical features, and literature to date. STUDY DESIGN Case report and review of the literature. METHODS Case records including paper and electronic chart and imaging reports were reviewed and summarized for the index case. A literature search was performed using pubmed keywords paraganglioma, hypoglossal, chemodactoma, carotid body, and glomus tumor. The available literature on the topic was reviewed and summarized. RESULTS Paragangliomas associated with the hypoglossal nerve were reported in 4 cases over the past 47 years. Our index case presented with similar clinical features compared to those reported in the literature. Imaging with computed tomography and angiography showed a hypervascular mass at the carotid bifurcation, splaying the internal and external carotid arteries. As in previously reported cases, the source of the paraganglioma was only identified intraoperatively. The current case differs from prior reported literature in that the tumor was dissected from the associated hypoglossal nerve which was preserved. The patient clinically had no deficits in articulation or deglutination following excision of the lesion and was able to return to a normal diet within 24 hours of surgery. CONCLUSIONS Hypoglossal paraganglioma is a neck mass that may not be distinguishable from more common carotid body or vagus tumors despite the use of multiple imaging modalities. Although XIIth nerve sacrifice may be requires in some instances, nerve preserving surgery, when possible, allows for complete recovery without functional deficits.

Potential Cytochrome P450 Drug-Drug Interactions among Pediatric Patients Undergoing Tonsillectomy

Objective To evaluate the frequency of potential cytochrome P450 (CYP) drug-drug interactions affecting opioid metabolism among children undergoing adenotonsillectomy. Study Design Case series with chart review. Setting Tertiary care children’s hospital. Subjects and Methods A retrospective review was conducted of 1000 patients undergoing adenotonsillectomy at Children’s Hospital of Wisconsin. The discharge medication reconciliation form was reviewed. Each patient’s list of medications was compared with various published sources to determine whether medications causing CYP inhibition or induction were present. Results There were 157 unique medications with systemic absorption given postoperatively to this patient cohort. Eight percent of patients were on at least 5 medications after surgery other than their posttonsillectomy medication. The 5 most commonly prescribed medications were albuterol, cetirizine, fluticasone nasal spray, montelukast, and polyethylene glycol. Per a list of known CYP inducers and inhibitors published by the US Food and Drug Administration, 30 (3%) patients were on a medication that inhibited CYP3A4; 1 patient was on a CYP3A4 inducer, prednisone; and 46 (5%) patients were on a medication that inhibited CYP2D6. Conclusions A small fraction of patients undergoing adenotonsillectomy are on medications that potentially alter the metabolism of opioid pain medications. Given the narrow therapeutic index of opioids and increased sensitivity to opioids among patients with obstructive sleep apnea, drug-drug interactions need to be considered as they relate to whether an opioid is appropriate and at what dose.

Endoscopic Removal of an Esophageal Button Battery under Fluoroscopic Guidance

As button batteries have become popular in recent years, there has been an associated increasing rate of esophageal injury due to battery ingestion by young children. Esophageal injury can occur rapidly because of the high electrical current produced by high-performance batteries. Severe complications include esophageal perforation, tracheoesophageal fistula, or esophageal scarring and stenosis requiring repeated dilatations or surgery. We discuss management of a difficult case caused by delayed presentation that resulted in significant esophageal injury by the time of endoscopy.