Biomedical subjects

D N Tobey

Publications and source records attributed to D N Tobey.

5 recordsLinked to original sources

PubMed1984

Use of direct posterior cricoarytenoid stimulation in laryngeal paralysis.

There are several methods used to restore impaired respiratory and phonatory function to the paralyzed larynx; but none are satisfactory. After we critically reviewed all available methods, we proposed a technique to rehabilitate the bilaterally paralyzed larynx, using selective stimulation of the posterior cricoarytenoid (PCA) muscle. This technique has the following advantages over existing methods: (1) preservation of phonation, (2) less chance of aspiration than with arytenoidectomy, and (3) reversibility. Adaptation of existing biomedical technology used in conjunction with any of several methods of triggering with respiration would make this a practical method. After insertion of electrodes into the PCA muscle of anesthetized animal subjects, selective electrical stimulation of this muscle was successfully accomplished. A significant reproducible increase in glottic area was demonstrated. Applicability to those suffering from bilateral laryngeal denervation seems feasible and functionally superior to existing methods of rehabilitation.

Animals↗

PubMed1979

Clinical features of diphtheria in the respiratory tract.

Clinical features of 44 culture-confirmed cases of diphtheria involving the respiratory tract treated at the University of Washington and affiliated hospitals in Seattle over a five-year period were studied. Of 42 patients treated primarily in Seattle, five (11.9%) died; nonfatal, toxin-induced complications occurred in seven (16.7%). Airway obstruction was the most common cause of death in this series. Diphtheritic membrane (especially in the larynx), dyspnea, and leukocytosis were dire prognostic signs. We urge indirect laryngoscopyin all cases showing membrane formation; tracheotomy should be considered when laryngeal membrane is present. Diphtheria should be suspected in any patient with pharyngitis who has been in contact with endemic areas, especially when pharyngeal membrane is present.

Adult↗

PubMedDate not supplied

Electron microscopy in the diagnosis of liposarcoma and fibrosarcoma of the larynx.

Electron microscopy (EM) was useful in establishing the final diagnosis in specific instances of liposarcoma and fibrosarcoma of the larynx. In the first case light microscopy revealed cells that met the histologic criteria of a low grade liposarcoma; EM revealed cells that displayed a varied ultrastructural differentiation; thus the tumor was classified as a mixed mesenchymal tumor rather than liposarcoma per se. In the second case, pathologic evaluation indicated a grade 2 fibrosarcoma. EM revealed malignant mesenchymal cells that closely recapitulated normal fibroblasts (no epithelial differentiation was present). This kind of information enables more accurate determination of the source of the primary lesion than results of light microcsopy alone.

Diagnosis, Differential↗

PubMedDate not supplied

Contralaterally elicited electrical stimulation of paralyzed facial muscles.

Functional electrical stimulation is being explored in the extremities. A major obstacle is found in programming the firing sequence. In 1976, David Zealear proposed using the activity on the normal side in axial muscle pairs that normally function symmetrically to act as a template to control the stimulator. This method was demonstrated in laryngeal muscles in dogs, and is now demonstrated in the face with future applications being proposed. The facial nerve on one side was sectioned in a series of rabbits. Implanted electrodes received electrical potentials from selected muscles on the normal side. Bursts of electrical activity on the normal side during a blink or a twitch were used to trigger a muscle stimulator, which was routed to matching muscles on the paralyzed side. This technique restored symmetric function to the hemiparalyzed side. This technique restored symmetric function to the hemiparalyzed face.

Animals↗

PubMedDate not supplied

Malignant cervical teratomas.

A case of malignant cervical teratomas is presented. Treatment based on chemotherapy protocols for testicular teratoma may improve the outcome of this rapidly progressive disease.

Head and Neck Neoplasms↗