Thyroid cartilage compression causing stroke.

We describe the diagnostic workup and surgical treatment of a patient presenting with the unique case of vertebral artery (VA) occlusion subsequent to head flexion leading to compression of an aberrant VA by the ipsilateral superior cornu of the thyroid cartilage. Imaging revealed ischemic infarcts as well as the presence of an aberrant right VA, which was compressed by the ipsilateral superior cornu of the thyroid cartilage upon neck flexion. The patient was managed with laryngoplasty involving removal of the right superior cornu of the thyroid cartilage. Laryngoscope, 129:E445-E448, 2019.

Lymphoma of the nasal cavity and paranasal sinuses: A case series.

BACKGROUND: Lymphomas of the sinonasal tract are a rare and heterogeneous subset of solid sinonasal neoplasms. OBJECTIVE: To characterize, in this case series, presenting symptoms, treatment modalities, and outcomes for patients with sinonasal lymphoma within a single institution. METHODS: Retrospective patient data were collected from an academic, oncologic center and entered into a repository designed to capture outcomes for sinonasal malignancies. Patient demographics, presenting symptoms, imaging findings, treatment modalities, and health status were retrospectively extrapolated and evaluated by using Kaplan-Meier estimations for survival probability. RESULTS: Patients with sinonasal lymphoma with a mean follow-up of 50 months were identified (n = 18). Histologic diagnosis included the following: diffuse large B-cell lymphoma (n = 9), natural killer/T-cell lymphoma (n = 5), follicular lymphoma (n = 1), T-cell lymphoma (n = 1), and lymphoma-not otherwise specified (n = 2). The most frequent presenting symptoms were nasal obstruction (78%), facial pain (72%), facial swelling (50%), and nasal discharge (44%). Treatment before lymphoma diagnosis included antibiotics (83%), oral steroids (22%), decongestants (22%), and topical steroids (11%). Treatment regimens after diagnosis included both chemotherapy (94%) and chemoradiotherapy (56%). Survival rates by lymphoma subtype were 56% for B-cell lymphoma and 40% for natural killer/T-cell lymphoma. Overall, 2- and 5-year survival rates were 67% and 50%, respectively. The combination of chemotherapy and radiation resulted in significantly higher survival rates (p ≤ 0.001) than chemotherapy alone. CONCLUSION: Sinonasal lymphomas are characterized by meager survival rates, which differ by histopathologic subtype. The diagnosis of sinonasal lymphoma is challenging because symptoms frequently parallel those of chronic rhinosinusitis. Increased awareness of these rare malignancies may improve detection and more timely treatment. Clinical trial registration NCT01332136.

Predictors of olfactory dysfunction in rhinosinusitis using the brief smell identification test.

OBJECTIVES/HYPOTHESIS: Associations between olfactory function to quality-of-life (QOL) and disease severity in patients with rhinosinusitis is poorly understood. We sought to evaluate and compare olfactory function between subgroups of patients with rhinosinusitis using the Brief Smell Identification Test (B-SIT). STUDY DESIGN: Cross-sectional evaluation of a multicenter cohort. METHODS: Patients with recurrent acute sinusitis and chronic rhinosinusitis with and without nasal polyposis were prospectively enrolled from three academic tertiary care sites. Each subject completed the B-SIT, in addition to measures of disease-specific QOL. Patient demographics, comorbidities, and clinical measures of disease severity were compared between patients with normal (BSIT≥9) and abnormal (BSIT<9) olfaction scores. Regression modeling was used to identify potential risk factors associated with olfactory impairment. RESULTS: Patients with rhinosinusitis (n=445) were found to suffer olfactory dysfunction as measured by the B-SIT (28.3%). Subgroups of rhinosinusitis differed in the degree of olfactory dysfunction reported. Worse disease severity, measured by computed tomography and nasal endoscopy, correlated to worse olfaction. Olfactory scores did not consistently correlate with the Rhinosinusitis Disability Index or Sinonasal Outcome Test scores. Regression models demonstrated nasal polyposis was the strongest predictor of olfactory dysfunction. Recalcitrant disease and aspirin intolerance were strongly predictive of worse olfactory function. CONCLUSIONS: Olfactory dysfunction is a complex, multifactorial process found to be differentially expressed within subgroups of rhinosinusitis. Olfaction was associated with disease severity as measured by imaging and endoscopy, with only weak associations to disease-specific QOL measures. LEVEL OF EVIDENCE: 2b.

Prospective study of venous thromboembolism in patients with head and neck cancer after surgery.

IMPORTANCE: Venous thromboembolism (VTE) is associated with significant morbidity and mortality in surgery patients, but little data exist on the incidence of VTE in head and neck cancer surgical patients. OBJECTIVE: To determine the incidence of VTE in postoperative patients with head and neck cancer. DESIGN, SETTING, AND PARTICIPANTS: A prospective study of 100 consecutive patients hospitalized at a tertiary care academic surgical center who underwent surgery to treat head and neck cancer. Routine chemoprophylaxis was not used. On postoperative day (POD) 2 or 3, participants received clinical examination and duplex ultrasonographic evaluation (US). Participants with negative findings on clinical examination and US were followed up clinically; participants with evidence of deep venous thrombosis (DVT) or pulmonary embolism (PE) were given therapeutic anticoagulation. Participants with superficial VTE underwent repeated US on POD 4, 5, or 6. Participants were monitored for 30 days after surgery. MAIN OUTCOME AND MEASURE: Total number of new cases of VTE (superficial and deep) identified within 30 days of surgery and confirmed on diagnostic imaging. RESULTS: Of the 111 participants enrolled, 11 withdrew before completing the study; thus, 100 participants were included. The overall incidence of VTE was 13%. Eight participants were identified with clinically significant VTE: 7 DVT and 1 PE. An additional 5 participants had asymptomatic lower extremity superficial VTE detected on US alone. Fourteen percent of patients received some form of postoperative anticoagulation therapy; the rate of bleeding complications in these patients (30.1%) was higher than that in patients without anticoagulation therapy (5.6%) (P = .01). CONCLUSIONS AND RELEVANCE: Hospitalized patients with head and neck cancer not routinely receiving anticoagulation therapy after surgery have an increased risk of VTE. Bleeding complications are elevated in patients receiving postoperative anticoagulation.

Prospective study of venous thromboembolism in patients with head and neck cancer after surgery: interim analysis.

OBJECTIVES: To prospectively determine the incidence of venous thromboembolism (VTE) following major head and neck surgery. At the midpoint of enrollment, an interim analysis was performed to determine if it was ethical to continue this study as an observational study without routine anticoagulation. DESIGN: Prospective, observational cohort study. SETTING: Academic surgical center. PATIENTS: The interim analysis comprised 47 subjects. MAIN OUTCOME MEASURE: The total number of new cases of VTE (superficial and deep) identified within 30 days of surgery and confirmed on diagnostic imaging. These cases were further categorized as clinically relevant and nonclinically relevant. Clinically relevant VTEs were those requiring more than 6 weeks of anticoagulation or were associated with any negative impact on clinical course. On postoperative day 2 or 3, subjects were clinically examined and received duplex ultrasonography. Subjects with negative findings from examination and ultrasonography were followed up clinically; subjects with evidence of deep venous thrombus or pulmonary embolism were given therapeutic anticoagulation. Subjects with superficial VTE received repeated ultrasonography on postoperative days 4 to 6. Subjects were monitored for 30 days after surgery. RESULTS: Three subjects (6%) were identified as having clinically significant VTE: 2 cases of deep venous thrombus and 1 case of pulmonary embolism. Two additional subjects had lower extremity superficial VTE without clinical findings, which were detected by ultrasonography alone. No statistically significant differences were seen between patients with VTE and those without VTE. CONCLUSIONS: This interim analysis of the first prospective study of the incidence of VTE in patients with head and neck cancer showed a VTE rate slightly higher than previously estimated in retrospective studies. There have been no unexpected serious adverse events and no rationale for early termination of the study.

Immunosuppressive therapy for autoimmune inner ear disease.

Autoimmune inner ear disease (AIED) is a rare disease that is diagnosed after clinical suspicion and response to corticosteroids. AIED manifests as progressive, bilateral, although often asynchronous, sensorineural hearing loss and can be associated with vestibular symptoms. Since its description as a defined disease entity in 1979, the initial mainstay of treatment remains high-dose corticosteroids. Several animal models have been developed to assist in determining efficacy of immunosuppression in AIED, and several clinical studies have also investigated the role of both steroid and steroid-sparing treatments. Here we discuss the basic science and clinical research surrounding the history of immunosuppressive therapy in AIED.

Distribution of voltage-gated potassium and hyperpolarization-activated channels in sensory afferent fibers in the rat carotid body.

The chemosensory glomus cells of the carotid body (CB) detect changes in O2 tension. Carotid sinus nerve fibers, which originate from peripheral sensory neurons located within the petrosal ganglion, innervate the CB. Release of transmitter from glomus cells activates the sensory afferent fibers to transmit information to the nucleus of the solitary tract in the brainstem. The ion channels expressed within the sensory nerve terminals play an essential role in the ability of the terminal to initiate action potentials in response to transmitter-evoked depolarization. However, with a few exceptions, the identity of ion channels expressed in these peripheral nerve fibers is unknown. This study addresses the expression of voltage-gated channels in the sensory fibers with a focus on channels that set the resting membrane potential and regulate discharge patterns. By using immunohistochemistry and fluorescence confocal microscopy, potassium channel subunits and HCN (hyperpolarization-activated) family members were localized both in petrosal neurons that expressed tyrosine hydroxylase and in the CSN axons within the carotid body. Channels contributing to resting membrane potential, including HCN2 responsible in part for I(h) current and the KCNQ2 and KCNQ5 subunits thought to underlie the neuronal "M current," were identified in the sensory neurons and their axons innervating the carotid body. In addition, the results presented here demonstrate expression of several potassium channels that shape the action potential and the frequency of discharge, including Kv1.4, Kv1.5, Kv4.3, and K(Ca) (BK). The role of these channels should be considered in interpretation of the fiber discharge in response to perturbation of the carotid body environment.

Abeta oligomer-induced aberrations in synapse composition, shape, and density provide a molecular basis for loss of connectivity in Alzheimer's disease.

The basis for memory loss in early Alzheimer's disease (AD) seems likely to involve synaptic damage caused by soluble Abeta-derived oligomers (ADDLs). ADDLs have been shown to build up in the brain and CSF of AD patients and are known to interfere with mechanisms of synaptic plasticity, acting as gain-of-function ligands that attach to synapses. Because of the correlation between AD dementia and synaptic degeneration, we investigated here the ability of ADDLs to affect synapse composition, structure, and abundance. Using highly differentiated cultures of hippocampal neurons, a preferred model for studies of synapse cell biology, we found that ADDLs bound to neurons with specificity, attaching to presumed excitatory pyramidal neurons but not GABAergic neurons. Fractionation of ADDLs bound to forebrain synaptosomes showed association with postsynaptic density complexes containing NMDA receptors, consistent with observed attachment of ADDLs to dendritic spines. During binding to hippocampal neurons, ADDLs promoted a rapid decrease in membrane expression of memory-related receptors (NMDA and EphB2). Continued exposure resulted in abnormal spine morphology, with induction of long thin spines reminiscent of the morphology found in mental retardation, deafferentation, and prionoses. Ultimately, ADDLs caused a significant decrease in spine density. Synaptic deterioration, which was accompanied by decreased levels of the spine cytoskeletal protein drebrin, was blocked by the Alzheimer's therapeutic drug Namenda. The observed disruption of dendritic spines links ADDLs to a major facet of AD pathology, providing strong evidence that ADDLs in AD brain cause neuropil damage believed to underlie dementia.

Kv1.1 deletion augments the afferent hypoxic chemosensory pathway and respiration.

Mutations in the potassium channel gene Kv1.1 are associated with human episodic ataxia type 1 (EA-1) syndrome characterized by movement disorders and epilepsy. Ataxic episodes in EA-1 patients are often associated with exercise or emotional stress, which suggests a prominent role for the autonomic nervous system. Many of these alterations are reproduced in the Kv1.1-null mouse. Kv1.1 also regulates excitability of sensory neurons essential in cardiovascular and respiratory reflexes. We examined the neural control of the respiratory system of littermate wild-type (control) and Kv1.1-null mice during low O2 (hypoxia). Immunohistochemical studies demonstrated Kv1.1 in the afferent limb of the carotid body chemoreflex (the major regulator in the response to hypoxia), consisting of the carotid body, petrosal ganglion, and nucleus of the solitary tract (NTS). Respiration was examined by plethysmography. Null mice exhibited a greater increase in respiration during hypoxia compared with controls. In vitro carotid body sensory discharge during hypoxia was greater in null than control mice. In the caudal NTS, evoked EPSCs in brainstem slices were similar between control and null mice. However, the frequency of spontaneous and miniature EPSCs was greater in null mice. Null mice also exhibited more asynchronous release after a stimulus train. These results demonstrate the important role of Kv1.1 in afferent chemosensory activity and suggest that mutations in the human Kv1.1 gene have functional consequences during stress responses that involve respiratory reflexes.

Synaptic targeting by Alzheimer's-related amyloid beta oligomers.

The cognitive hallmark of early Alzheimer's disease (AD) is an extraordinary inability to form new memories. For many years, this dementia was attributed to nerve-cell death induced by deposits of fibrillar amyloid beta (Abeta). A newer hypothesis has emerged, however, in which early memory loss is considered a synapse failure caused by soluble Abeta oligomers. Such oligomers rapidly block long-term potentiation, a classic experimental paradigm for synaptic plasticity, and they are strikingly elevated in AD brain tissue and transgenic-mouse AD models. The current work characterizes the manner in which Abeta oligomers attack neurons. Antibodies raised against synthetic oligomers applied to AD brain sections were found to give diffuse stain around neuronal cell bodies, suggestive of a dendritic pattern, whereas soluble brain extracts showed robust AD-dependent reactivity in dot immunoblots. Antigens in unfractionated AD extracts attached with specificity to cultured rat hippocampal neurons, binding within dendritic arbors at discrete puncta. Crude fractionation showed ligand size to be between 10 and 100 kDa. Synthetic Abeta oligomers of the same size gave identical punctate binding, which was highly selective for particular neurons. Image analysis by confocal double-label immunofluorescence established that >90% of the punctate oligomer binding sites colocalized with the synaptic marker PSD-95 (postsynaptic density protein 95). Synaptic binding was accompanied by ectopic induction of Arc, a synaptic immediate-early gene, the overexpression of which has been linked to dysfunctional learning. Results suggest the hypothesis that targeting and functional disruption of particular synapses by Abeta oligomers may provide a molecular basis for the specific loss of memory function in early AD.

Distribution of TRPC channels in a visceral sensory pathway.

Until recently most of the published studies addressing the mechanisms of activation of TRPC channels have been carried out in heterologous expression systems. Lack of specific antagonists for the TRPC channels has hampered functional studies of endogenous channels. We approached the role of TRPC channels in native tissue with a study of the distribution of the channel proteins in the carotid chemosensory pathway in the rat. In a previous report we showed that TRPC3/4/5/6 and TRPC7 were present in neurons throughout the petrosal ganglion while TRPC1 was expressed in only a subpopulation of petrosal neurons, at least half of which projected to the carotid body. The TRPC proteins were differentially distributed to the branches of the axons that project centrally to the nucleus of the solitary tract and peripherally to the carotid body. The smallest unmyelinated sensory fibres projecting to the carotid body contained TRPC1/3/4/5 or TRPC6 but not TRPC7. TRPC1 and TRPC3 were concentrated in the larger diameter fibres. Interestingly, only TRPC1 and TRPC4 could be demonstrated in the final terminal endings within glomus cell clusters of the carotid body. In the central axon of the sensory neurons, both TRPC4 and TRPC5 were demonstrated in fibres exiting the solitary tract and projecting to the secondary relay neurons the nucleus of the solitary tract.

Distribution of transient receptor potential channels in the rat carotid chemosensory pathway.

Glomus cells in the carotid body respond to decreases in oxygen tension of the blood and transmit this sensory information in the carotid sinus nerve to the brain via neurons in the petrosal ganglion. G-protein-coupled membrane receptors linked to phospholipase C may play an important role in this response through the activation of the cation channels formed by the transient receptor potential (TRP) proteins. In the present study, expression of TRPC proteins in the rat carotid body and petrosal ganglion was examined using immunohistochemical techniques. TRPC3, TRPC4, TRPC5, TRPC6, and TRPC7 were present in neurons throughout the ganglion. TRPC1 was expressed in only 28% of petrosal neurons, and of this population, 45% were tyrosine hydroxylase (TH)-positive, accounting for essentially all the TH-expressing neurons in the ganglion. Because TH-positive neurons project to the carotid body, this result suggests that TRPC1 is selectively associated with the chemosensory pathway. Confocal images through the carotid body showed that TRPC1/3/4/5/6 proteins localize to the carotid sinus nerve fibers, some of which were immunoreactive to an anti-neurofilament (NF) antibody cocktail. TRPC1 and TRPC3 were present in both NF-positive and NF-negative fibers, whereas TPRC4, TRPC5, and TRPC6 expression was primarily localized to NF-negative fibers. Only TRPC1 and TRPC4 were localized in the afferent nerve terminals that encircle individual glomus cells. TRPC7 was not expressed in sensory fibers. All the TRPC proteins studied were present in type I glomus cells. Although their role as receptor-activated cation channels in the chemosensory pathway is yet to be established, the presence of TRPC channels in glomus cells and sensory nerves of the carotid body suggests a role in facilitating and/or sustaining the hypoxic response.