PubMed Health⌕ Search

Biomedical subjects

R Metson

Publications and source records attributed to R Metson.

34 records · Page 2Linked to original sources
PubMed1991

Endoscopic surgery for lacrimal obstruction.

Intranasal access to the lacrimal drainage system has been greatly enhanced with the advent of endoscopic nasal surgery. This technique has been used for the treatment of recurrent lacrimal obstruction after failed external dacryocystorhinostomy (DCR) in 12 patients. Improved intranasal visualization with the endoscope allowed easy identification and opening of the lacrimal sac, with no need for a skin incision. Obstructing intranasal pathology, including adhesions from previous DCR, an enlarged middle turbinate, and ethmoid sinus disease, was readily identified and corrected. There were no intraoperative complications. Lacrimal obstruction was completely relieved in nine of 12 patients (75%), with a followup of 7 to 25 months. Endoscopic revision DCR should be considered in patients with recurrent epiphora after external DCR.

Adult↗
PubMed1991

Magnetic stimulation of the facial nerve.

Intracranial activation of the facial nerve is now possible with the noninvasive techniques of magnetic stimulation. Brief magnetic pulses generated by a coil overlying the parietal scalp elicit compound muscle action potentials of similar shape and amplitude and greater latency than those produced by electroneurography. Mapping studies demonstrate the compound muscle action potentials to be of constant latency and varying amplitude with changing coil location. Maximum compound muscle action potential amplitudes are obtained with the coil center located in a rectangular area superior and posterior to the ear canal. A comparison of large and small diameter coils showed them to be equally effective for painless facial nerve stimulation; however, the smaller coil allowed for a more localized field of activation. Magnetic stimulation has the potential to provide cross-the-lesion testing of facial nerve function.

Action Potentials↗
PubMed1991

Preservation of the facial nerve in the management of recurrent pleomorphic adenoma.

Whether to preserve or sacrifice a facial nerve involved with benign neoplasm is one of the most difficult intraoperative decisions confronting the head and neck surgeon. We reviewed 21 cases of recurrent pleomorphic adenoma treated with subtotal excision and facial nerve preservation, followed by postoperative radiation therapy. Of the 17 patients with microscopic residual tumor at completion of surgery, 16 (94%) remain free of recurrence with an average follow-up of 5.9 years. Only one of four patients (25%) with a large postoperative tumor load remains free of disease. Facial nerve function is normal in 20 of 21 patients. Preservation of the facial nerve with postoperative irradiation should be considered as an alternative to nerve sacrifice in selected cases of recurrent pleomorphic adenoma.

Adenoma, Pleomorphic↗
PubMed1990

Nasopharyngeal mass: a manifestation of inflammatory otologic disease.

A nasopharyngeal mass with cranial neuropathies usually indicates an advanced neoplastic process. We present three patients with these findings and concurrent invasive Pseudomonas otitis in whom repeated nasopharyngeal biopsies were negative for tumor. All of the nasopharyngeal masses resolved following treatment of the otitis. Mechanisms of disease spread from the temporal bone to the nasopharynx are discussed. Clinicians may choose to modify diagnostic and therapeutic approaches to the nasopharyngeal mass in patients with concurrent invasive otologic disease.

Aged↗
PubMed1988

Facial nerve evoked potentials in the cat.

Electrophysiologic facial nerve testing usually involves stimulation of the peripheral nerve in order to make some indirect inference about nerve integrity at a more proximal site of lesion. In an attempt to develop a test of facial nerve function by use of across-the-lesion testing, the cat facial nerve was stimulated percutaneously at the stylomastoid foramen while retrograde activity through the temporal bone and cranium was monitored with scalp electrodes. A biphasic evoked potential could be identified within 3 milliseconds of stimulation with the use of a signal-averaging computer. This potential remained when the animal was paralyzed and disappeared when the facial nerve was cut proximal to the stimulation site. A potential of similar latency and duration but larger amplitude was recorded from the subarachnoid space. Mapping studies indicated its origin to be a dipole located between ipsilateral mastoid and parietal recording sites that corresponded to the region of the intracranial facial nerve. Optimal stimulation and recording techniques for subsequent studies of human beings are discussed.

Animals↗
PubMed1988

Surgical complications following twice-a-day versus once-a-day radiation therapy.

With increasing numbers of radiotherapists using twice-a-day (BID) rather than conventional once-a-day (QD) radiation therapy to treat carcinomas of the head and neck, we attempted to determine whether the increased tissue reaction seen with a BID program results in greater morbidity for subsequent surgery. Postoperative complications in 24 patients receiving prior BID irradiation were compared with 37 controls receiving QD treatments. The incidence of major surgical complications for BID and QD groups was equivalent (20.8% and 18.9%, respectively). The incidence of minor complications was almost three times greater for the BID group (37.5% vs. 13.5%). Patients receiving BID radiation therapy required twice as many intraoperative transfusions (2.13 vs. 1.11) and five additional days of postoperative hospitalization (23.7 vs. 18.2). These differences are statistically significant with p-values of less than 0.5 and less than 0.1, respectively. We consider this increase in surgical morbidity to be acceptable if BID radiation therapy leads to improved tumor control.

Combined Modality Therapy↗
PubMed1988

Internal maxillary artery ligation for epistaxis: an analysis of failures.

The records of 100 consecutive patients undergoing transantral ligation of the internal maxillary artery (IMA) for epistaxis, including 15 patients who developed postoperative bleeding, were reviewed. Preoperative parameters predictive of surgical failure were advanced age, anemia, and a history of hypertension. The causes of postoperative epistaxis, as determined by surgical reexploration or angiography in 12 cases, included failure to identify the IMA in the pterygomaxillary space (6 cases), blood flow through partially closed clips on the IMA (2 cases), bleeding from posterior ethmoid arteries (2 cases), and revascularization of the nasal blood supply (2 cases). The incidence of surgical failure may be reduced by proper techniques of IMA identification and ligation.

Epistaxis↗
PubMed1986

Tetracycline sclerotherapy for chylous fistula following neck dissection.

In chylous fistulas following radical neck dissections, we have found reexploration to be unrewarding, with infrequent identification of a specific leakage site intraoperatively and persistent fluid accumulation postoperatively. As an alternative, we injected tetracycline hydrochloride into the supraclavicular wound bed. This procedure resulted in a rapid, sustained decline in fistula output in two of three cases, avoiding surgical intervention. Tetracycline sclerotherapy has been described for treatment of intrathoracic and other intracavitary fluid collections. We believe that tetracycline sclerotherapy is an effective adjunct in the management of chylous fistulas following radical neck dissections and that this therapy should be attempted before surgical reexploration.

Adenocarcinoma↗
PubMed1985

Facial nerve evoked potentials.

Evoked potentials representing both intracranial and extracranial activity have been recorded from the canine scalp after retrograde stimulation of peripheral facial nerve branches. A negative electrode at the vertex and a positive electrode at the ipsilateral mastoid (grounded at the contralateral mastoid) show a monophasic negative stylomastoid evoked potential that appears to be generated from the facial nerve trunk at the stylomastoid foramen. When the positive electrode is moved from the mastoid to the posterior scalp (overlying the foramen magnum), a similar potential with a latency 1.5 msec greater is obtained. This brain stem evoked potential is generated from fibers in the vicinity of the root entry zone and the initial trajectory into the brain stem. A potential of similar latency but greater magnitude is recorded with the positive electrode in the cerebrospinal fluid of the posterior fossa.

Animals↗
PubMed1984

Kawasaki disease in adults. An otolaryngologist's perspective.

Kawasaki disease has been recognized for more than 15 years in children, but it is only recently that adult cases have been known to occur. One such case is reported herein. The cases of previously described adult patients are reviewed in depth, emphasizing the otolaryngologic findings. Diagnosis is based on clinical findings with prominent fever, oropharyngeal erythema, dermatitis, and cervical lymphadenopathy. The underlying lesion is a vasculitis and treatment is mainly supportive, although aspirin seems to have some value in the prevention of cardiac complications.

Adolescent↗
PubMed1983

Bilateral facial nerve paralysis following arterial embolization for epistaxis.

Risk of carotid artery embolization is usually attributed to inadvertent occlusion of the internal carotid system. This report highlights some recently noted complications associated with occlusion of external carotid branches. A case of bilateral facial paralysis following embolization of the internal maxillary arteries for severe epistaxis is presented. The clinician must recognize that facial paralysis is a real and sometimes inevitable sequela to the ever-increasing practice of arterial embolization in the head and neck.

Arteries↗