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Biomedical subjects

R W Babin

Publications and source records attributed to R W Babin.

At least 37 records · Page 2Linked to original sources
PubMed1982

The vestibular system in the elderly.

Aging in the peripheral vestibular apparatus is shown to consist of processes similar to those occurring in other parts of the nervous system. Sensory epithelium and primary efferents degenerate and are not replaced. Type I hair cells and elements of the pars inferior are most susceptible. Remaining cells show a build-up of lipofuscin and microstructural changes suggesting compromised metabolism. Rupture of the saccular membrane and microfractures of the otic capsule are frequently seen. Otoconia undergo degeneration, and the tissue between the endolymphatic duct and bony vestibular aqueduct becomes fibrotic. The recognition of these findings is a first step in the clinical delineation of the "dysequilibrium of aging" from symptoms related to specific disease processes. Further clinical correlation will remain difficult until changes in the central vestibular pathways and their connections with the optic and locomotor systems are better understood.

Aging↗
PubMed1981

Traumatic neuromas of the facial nerve.

The temporal bones in two patients contained asymptomatic neuromas of the facial nerve and a third patient had an identical tumor of the chorda tympani. All three neuromas occurred in the presence of chronic inflammatory middle ear disease. Histologically all three resembled traumatic (repairative) neuromas. Both of the facial nerve lesions occurred at a site of frequent fallopian canal dehiscence. It is suggested that occasionally, long-term exposure to the facial nerve to chronic inflammation results in proliferation of neurofibrils leading to neuroma formation.

Adolescent↗
PubMed1981

Nonlinear characteristics of single neurons in the vestibular nuclei.

The characteristics of response of 99 vestibular nuclei neurons were investigated in the cat anesthetized with pentobarbital sodium. All neurons responded to stimulation of the horizontal semicircular canals (HSCC) with prolonged 2, 4, 6, or 8 degrees/second2 angular acceleration. Neural response was recorded utilizing the single-neuron recording technique. The vestibular neurons responded nonlinearly to stimulation of the HSCC. Specifically (1) the time required to reach the maximum response level decreased nonlinearly with an increase in stimulus magnitude (SM); (2) the maximum response level increased nonlinearly with the increase in SM: (3) the neural response to excitatory stimulus was not the mirror image of that to an inhibitory stimulus. Several existing mathematical models were simulated by utilization of the IBM Continuous System Modeling Program, account for the nonlinear response of the vestibular nuclei neurons. The nonlinearities observed in the responses may be due to (1) nonlinear behavior of the end organ, (2) the influence of the CNS including the vestibular efferent system, or (3) the inherent neural properties of the vestibular nuclei.

Acceleration↗
PubMed1980

Responses to step and repeated impulse accelerations in second order vestibular neurons of the cat.

The characteristics of response of 98 vestibular nuclei neurons were investigated in the barbiturate anesthetized cat. All type I and type II neurons (tonic and kinetic) responded to stimulation of the horizontal canals with step and impulse accelerations. Seventy-seven (79 per cent) neurons of all types demonstrated adaptation, while the remaining 21 (21 per cent) neurons showed either reverse adaptation or no adaptation. When the interval between impulses with impulse accelerations reached a critical minimum, the averaged response was remarkably like the response to step acceleration, including the rate of adaptation. A previously undescribed response decline to repetitive impulse acceleration was seen, which, while sharing some characteristics with habituation, appears to be more closely related to adaptation. Furthermore, the data suggest that adaptation seen at the vestibular nuclear level is more likely a central phenomenon rather than a peripheral one.

Acceleration↗
PubMed1980

The incidence of vasovagal reflex activity during radical neck dissection.

Pressure receptors exist within the walls of the carotid bulb which are responsible for maintaining the balance between blood volume, vascular tone, and cardiac output. When these receptors are manipulated during neck surgery the result may be bradycardia, hypotension or cardiac arrythmia. Such events occur sporatically during head and neck surgery and occasionally may prove fatal. While many surgeons advocate anesthetizing the carotid bulb prophylactically, this practice is not universally accepted. A retrospective appraisal of 76 radical neck dissections demonstrated an incidence of clear cut vasovagal reflex activity of 10%. Thirty-one radical neck procedures were then randomized into treatment and control groups in a prospective fashion. The treatment group (12 patients) had 5 cc. of 2% lidocaine applied topically to the carotid bifurcation. Nineteen controls had normal saline applied to the same site. The incidence of vasovagal reflexes in the control group was 10% and 16% in the treatment group. The similarity of these treatment groups is highly significant. It is concluded that topical 2% lidocaine is not an adequate prophylaxis for vasovagal reflexes during radical neck dissection.

Anesthesia, Local↗
PubMed1980

Urea test and vestibular dysfunction in suspected Ménière's disease.

Twenty-four consecutive patients underwent urea testing as part of a diagnostic work-up for vertigo and/or fluctuating hearing loss. Latent and positional nystagmus were evaluated by electronystagmography before and after urea ingestion. Of 10 patients with no nystagmus pre urea, only one exhibited slight latent nystagmus post urea. Of 14 patients with latent or positional nystagmus prior to the urea test, two lost their nystagmus, four showed marked decrease in slow component velocity, and eight were unchanged. No correlation could be made with cochlear response. Direction changing positional nystagmus showed a greater propensity to resolve with urea than did latent nystagmus. It is concluded that urea does not, like glycerol, cause an ageotropic direction changing positional nystagmus and allows for a more accurate evaluation of vestibular function following osmolar diuresis than glycerol does.

Electronystagmography↗
PubMed1979

Surgical management of nasal valvular obstruction of dorsal origin.

Nasal obstruction from valvular dysfunction may take many forms besides alar collapse. Some valvular stenoses result from scarring and tissue loss from the dorsum of the nose. Any surgical correction should take into consideration replacement of lost tissue. Several surgical means of handling this type of obstruction are described.

Humans↗
PubMed1979

Combined modalities in the management of hypertrophic scars and keloids.

A surgeon has many treatment options available during the longterm management of a patient with keloids or hypertrophic scars. The thoughtful combination of multiple modalities in a staged manner may produce a more favorable result than the application of a single technique. A case is presented which illustrates the concept of preliminary treatment with cryotherapy and low dose intralesional triamcinolone followed at interval by surgical excision.

Cicatrix↗
PubMed1978

The nasal dorsum flap.

Closure of full-thickness defects of the nasal tip and sorsum requires both a satisfactory functional and an acceptable cosmetic result. The nasal dorsum flap is particularly well suited for closure of many such defects. The basic design of the flap, as well as several useful modifications, are discussed.

Humans↗
PubMed1977

Combination flap closure of facial defects.

In the past, combining local flaps to close skin defects has emphasized the shape of the defect. Combining local flaps on the basis of facial features and available donor skin has clear-cut advantages over single flap and regional flap closures in selected cases. Facial features may be more readily preserved and incision lines more easily disguised. A successful functional and cosmetic result is dependent on flap selection and design, as well as meticulous handling of skin and closure technics.

Basal Cell Carcinoma↗
PubMed1975

Anatomic and radiographic correlates in the middle ear.

An experiment was designed to determine the frequency with which the stapes could be visualized radiographically. Ten human temporal bones were radiographically sectioned before and after stapedectomy using three routine views, and with lead-coated stapes replaced in the oval window. Five human temporal bones were radiographically sectioned before and after stapedectomy using the Guillen view, that is, with the tympanic cavity viewed through the orbit, and with the head tilted 15 degrees to the side under investigation. The Guillen view proved to be superior for evaluating the foot-plate and superstructure of the stapes because it placed these structures in a favorable position for contact with the x-ray beam.

Ear, Middle↗
PubMedDate not supplied

Temporal bone pathology in drowning.

The temporal bones of a 2-year-old child who had drowned were examined histopathologically. The abnormalities were limited to the submucosa and lumen of the tympanomastoid space. Abnormalities included severe edema, vascular congestion, and focal ecchymosis without inflammation in the submucosa and hemorrhage into the tympanomastoid air space. To determine the incidence of tympanomastoid hemorrhage in autopsy material, 258 temporal bones were reviewed, and 11 were found to have free blood in the tympanomastoid space. When specimens from victims of skull fractures, cerebrovascular accidents, and leukemia were excluded from the 11, the only specimen remaining was found to be that from a drowning victim. Tympanomastoid hemorrhage in the absence of otitis media, head trauma, cerebrovascular accident, or a bleeding diathesis appears to be strong supporting evidence for death by drowning.

Child, Preschool↗