Environmental risks of chlorofluorocarbon anesthetic agents.
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Air Pollutants, Occupational↗
Biomedical subjects
R A Hendrix
Publications and source records attributed to R A Hendrix.
Central nodal necrosis and extracapsular neoplastic spread in cervical lymph nodes: MR imaging versus CT.
Computed tomographic (CT) scans and magnetic resonance (MR) images obtained in 24 patients with cervical lymphadenopathy were retrospectively and blindly evaluated by two readers for the presence of central nodal necrosis (CNN) and extracapsular nodal spread (ENS). The CT studies were all enhanced, and the MR images were obtained with short repetition time (TR)/echo time (TE), long TR/double echo, and enhanced short TR/TE fat-suppressed sequences. Each MR imaging sequence was interpreted separately and then collectively. Sixty lymph nodes were identified with CT. Sensitivity for CNN was 16%-67% with the unenhanced MR pulse sequences, 50% with enhanced sequences, and 83%-100% with CT. The most accurate reading of MR images for CNN was with the unenhanced T1-weighted and T2-weighted images (86%-87%); the accuracy of CT was 91%-96%. The accuracy of MR imaging for detecting ENS was maximal with T1-weighted images (78%-90%). Gadolinium-enhanced, fat-suppressed images did not improve accuracy in evaluating CNN or ENS. CT is currently more accurate than unenhanced or enhanced MR imaging in detecting CNN or ENS.
Carcinoma, Squamous Cell↗
Open tube versus flexible esophagoscopy in adult head and neck endoscopy.
Open tube esophagoscopy is the mainstay of otolaryngic esophageal examination. Over the last 30 years flexible endoscopes have become popular and are challenging the open tube esophagoscope for use in otolaryngic practice. This study examines all open tube esophagoscopies performed on adult patients at the University of Pennsylvania over an 8-year period for the diagnosis and treatment of foreign bodies, strictures, functional disorders, and carcinoma. Open tube esophagoscopy is most useful for foreign body extraction, examination of the cervical esophagus, and dilation of pliable strictures. For most other indications flexible esophagoscopy provides improved visualization with lower morbidity. For patients with squamous cell carcinoma of the head and neck we found a 1.4% incidence of secondary esophageal malignancies and a 28% incidence of false-negative barium swallow studies. We recommend esophagoscopy for all patients with carcinoma of the upper aerodigestive tract. The otolaryngologist should be adept at both flexible and open tube esophagoscopy in order to allow optimal examination of and therapeutic intervention in the upper aerodigestive tract.
Barium Sulfate↗
Chiari-I malformation associated with asymmetric sensorineural hearing loss.
Chiari-I malformation is a deformity of the structures of the posterior fossa in which there is inferior herniation of the cerebellar tonsils through the foramen magnum without significant caudal dislocation of the brainstem. Patients are usually asymptomatic until adulthood, when they commonly present with recurrent headaches, weakness, vertigo and/or imbalance, nystagmus and hearing loss. A review of 226 consecutive patients evaluated for asymmetric sensorineural hearing loss revealed 32 patients with retrocochlear pathology. Three of these patients were discovered to have a Chiari-I malformation by magnetic resonance imaging as their only pathology. We suggest a possible association between a Chiari-I malformation and isolated asymmetric sensorineural hearing loss secondary to long-standing traction on the eighth cranial nerve.
Adult↗
Laryngeal manifestations of gout.
Gout is a disorder of purine metabolism characterized by hyperuricemia with rare involvement of the head and neck. We present a 72-year-old woman with a known history of gout who presented with hoarseness and a lesion suspicious for carcinoma of the larynx. Endoscopic biopsy revealed a tophus of the true vocal cord with characteristic birefringent crystalline deposits and giant cell granuloma. There have been limited reports of gouty involvement of the larynx, more commonly involving cricoarytenoid arthritis. Tophi of the laryngeal soft tissues are exceedingly rare. In this paper we will discuss the pathophysiology and management of this interesting clinical entity.
Aged↗
The infectious and hematologic otolaryngic complications of myelosuppressive cancer chemotherapy.
The otolaryngologist-head and neck surgeon is frequently consulted to evaluate patients before the administration of myelosuppressive cancer chemotherapy. Fifty consecutive patients treated at the University of Pennsylvania Oncology Center were studied before and during chemotherapy for adult leukemia or bone marrow transplantation. Otolaryngic history, physical examination, radiographic studies, and hematologic surveys were analyzed for the duration of therapy in an attempt to identify risk factors for infectious and hematologic otolaryngic complications. Two-thirds of the patient studied experienced untoward effects that required the further attention of an otolaryngologist-head and neck surgeon. The various complications and associated correlations with the study parameters before and during chemotherapy are discussed.
Acute Disease↗
The Chiari-I malformation.
We have described the important clinical features and aspects of the Chiari-I malformations, with particular emphasis on Chiari-I malformation. Previously thought to be a rare finding with only minor significance, Chiari-I malformation is an important cause of a variety of symptoms, and will be diagnosed even more frequently as the use of MRI increases. The clinician must consider Chiari-I malformation in any patient with unexplained sensorineural hearing loss, headache, vertigo, ataxia, dysequilibrium, dysphagia or other cranial nerve symptom, especially if accompanied by more classic symptoms of this disorder, such as cervical pain or weakness.
Arnold-Chiari Malformation↗
The otolaryngic manifestations of multiple sclerosis.
Multiple sclerosis is a disease characterized pathologically by the disseminated demyelination of central nervous system white matter and clinically by episodes of focal neurologic deficit that occur in a relapsing and remitting course usually over many years. In most cases progressively fixed deficits occur with resultant moderate to severe disability. Symptoms and signs of multiple sclerosis are reviewed, with emphasis placed on the protean manifestations and natural history of the disease.
Clinical Protocols↗
Iatrogenic subcutaneous cervicofacial and mediastinal emphysema.
Subcutaneous emphysema of the head, neck and mediastinum occurs with a variety of disease processes. Most cases involve the passive escape of air from the aerodigestive tract into subcutaneous tissues. The many causes include head and neck surgical procedures, tracheal and esophageal trauma, intraoral trauma, foreign bodies and neoplasms of the aerodigestive tract, and pulmonary barotrauma from mechanical ventilation or in patients with pulmonary disorders. Subcutaneous emphysema secondary to active injection of air has recently been reported following certain dental procedures. An interesting case of diffuse cervicofacial and mediastinal emphysema following a difficult extraction of an infected lower molar tooth with a high-pressure air drill is presented. The patient required airway observation and high-dose antibiotic therapy. Early recognition of this unique problem is essential in preventing such life-threatening complications as airway obstruction, mediastinitis, deep neck infection, and cardiac failure. Diagnostic and therapeutic recommendations are included.
Humans↗
The use of diagnostic testing in asymmetric sensorineural hearing loss.
The etiology of an asymmetric sensorineural hearing loss can often be difficult to determine. Because a wide variety of pathologic processes may be responsible for the hearing loss, numerous diagnostic tests are usually used in the initial evaluation, including pure-tone audiometry, acoustic reflex testing, imaging, serologic testing, and auditory brainstem response testing. The diagnostic evaluations of 225 consecutive cases of asymmetric sensorineural hearing loss are reviewed. A cochlear site-of-lesion was demonstrated in the majority (194) of patients. Because all retrocochlear lesions (31) were associated with an abnormal auditory brainstem response, imaging should be performed in that group of patients. Magnetic resonance imaging offers greater specificity than computed tomography. Reflex decay, acoustic reflex testing, and rollover were all associated with a high false-negative rate. Whereas serologic testing for syphilis yielded several cases of otosyphilis, thyroid function testing was of little value. A diagnostic protocol for asymmetric sensorineural hearing loss is presented.
Adolescent↗
31P localized magnetic resonance spectroscopy of head and neck tumors--preliminary findings.
Magnetic resonance imaging (MRI) is a powerful tool for accurate assessment of the anatomic extent of head and neck neoplasms. The development of methods for spatial localization by use of multiply tuned radio frequency coils that permit the measurement of multiple nuclear MR spectra (1H and 31P) from precisely defined volumes of interest has provided a basis for integrating spectroscopy into the clinical MRI examination. This offers a means for noninvasive monitoring of relative concentrations of mobile metabolites within a tumor. With the use of imaging to determine proper coil placement, a test-retest variance of about 17% is seen on MR spectroscopy. Data are presented from MRI/MRS studies for four head and neck lesions: (1) a squamous cell carcinoma of the lip; (2) a juvenile angiofibroma extending into the nasal cavity; (3) a massive chondrosarcoma of the nasal septum; and (4) a cervical nodal metastasis of a squamous cell carcinoma of the pharynx. Spectra are evaluated by comparison of relative concentrations of phosphorus compounds. The concentrations of phosphomonoesters and phosphodiesters are significantly higher in the neoplasms studied than in normal skeletal muscle. The developing role of integrated MRI/MRS to monitor the response of malignant neoplasm to radiation therapy is discussed.
Adult↗
Localization of the carotid artery within the tonsillar fossa by Doppler flow mapping.
Injury to the internal carotid artery during procedures performed in the tonsillar fossa can be catastrophic. Tonsillectomy or uvulopalatopharyngoplasty was performed on 32 patients at the Hospital of the University of Pennsylvania or the Children's Hospital of Philadelphia. Using Doppler ultrasonography, the course of the internal carotid artery in the postsurgical tonsillar fossa was mapped. The results indicate that, in the majority of patients, the internal carotid artery is located between 20% and 60% of the total width across the tonsillar fossa, as measured from the posterior pillar. Appreciation of the surgical anatomy of the tonsillar fossa with respect to the internal carotid artery should contribute to improved intraoperative judgment and further limit the risk of vascular injury during oropharyngeal procedures.
Adolescent↗
Transsphenoidal hypophysectomy: a critical review.
The approach to resection of pituitary tumors has undergone radical changes over the past one hundred years and continues to change. Prolactinomas are the most common indication for hypophysectomy. While transsphenoidal hypophysectomy has now become the standard surgical procedure for gaining access to the pituitary fossa, alternative methods of approaching the sphenoid sinus are advocated. A thorough knowledge of sinonasal anatomy is essential for these transsphenoidal procedures, necessitating otolaryngologic consultation. While mortality is low with any of these procedures, the morbidity of the sublabial approach may be avoided with alternative techniques.
Contraindications↗
Inverted papillomas of the nasal septum.
The inverted papilloma is a true neoplasm of the nose and paranasal sinuses with unusual biological and clinical characteristics. It is a benign process which exhibits certain malignant features such as recurrence, localized destruction of tissues and the possibility of malignant degeneration. Inverted papillomas occur most commonly on the lateral nasal wall, but a small percentage are discovered elsewhere including the ethmoid and sphenoid sinuses, the nasopharynx and the nasal septum. Controversy exists about whether septal papillomas are true inverted papillomas or whether they represent the more commonplace squamous papillomas found in the upper respiratory tract. Two case reports of inverted papillomas of the nasal septum are presented as well as a review of the literature on these neoplasms.
Adult↗
The diagnosis of Thornwaldt's cyst.
Thornwaldt's cyst is an uncommon nasopharyngeal lesion which develops from the remnant of the primitive notochord. A case report of a patient with a Thornwaldt's cyst and cervical adenitis is presented. Though computed tomography of the head and neck was unremarkable, magnetic resonance imaging of the nasopharynx revealed the Thornwaldt's cyst, suggesting that this modality may be more sensitive in detecting and evaluating cystic lesions of the nasopharynx. The differential diagnosis of cystic nasopharyngeal masses is discussed.
Adult↗
Perilymph fistula.
Perilymph fistula, an abnormal communication between the inner ear and the middle ear, is an enigmatic otologic disorder which may present with auditory or vestibular symptoms. It is typically located at the oval or round windows, but several other locations have been suggested. It may be congenital or spontaneous, or due to trauma or surgery. It often poses a diagnostic dilemma because of the lack of a definitive test. Among the differential diagnoses of the perilymph fistula are Ménière's disease, infection, tumor and central nervous system disorders. Clinically, the definitive diagnosis of a perilymph fistula can only be made by exploratory tympanotomy. A current review of the etiology, diagnosis and management of perilymph fistula is presented.
Diagnosis, Differential↗
Angiotensin-converting enzyme inhibitor induced angioedema of the head and neck.
Angiotensin-converting enzyme (ACE) inhibitors are now in widespread use for the treatment of essential and renovascular hypertension. Consequently, angioedema, an uncommon complication of ACE inhibitor therapy is being encountered with increasing frequency. Since ACE inhibitor angioedema predominantly involves the face, lips, oral cavity, and occasionally the larynx the otolaryngologist is often consulted to evaluate affected patients. Treatment ranges from simple cessation of the drug to emergent airway intervention. The pertinent pharmacologic properties of ACE inhibitors and the pathophysiology of angioedema are discussed. The authors' experience with the evaluation and treatment of ACE inhibitor induced angioedema is presented.
Adrenal Cortex Hormones↗