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Biomedical subjects

P R Lambert

Publications and source records attributed to P R Lambert.

52 records · Page 3Linked to original sources
PubMed1987

Meningitis and facial paresis. Implications for cochlear implantation.

Most postlingually deafened individuals receive auditory sensations with a cochlear implant. We describe a postmeningitic patient with bilateral facial paresis who failed to be stimulated with a multichannel device. In light of the facial dysfunction, primary auditory nerve damage by meningitis is postulated as the cause of implant failure. Preoperation electrical stimulation of the cochlea using an alternating current signal is recommended as a means of assessing cochlear implant candidacy.

Cochlear Implants↗
PubMed1986

The interaction of noise and aspirin in the chick basilar papilla. Noise and aspirin toxicity.

The possible synergism between noise and aspirin for causing cochlear damage was examined histologically. Six chicks fed aspirin for five days and five chicks fed a normal diet only were paired and placed in sound chambers. They were exposed to a 1500-Hz tone at 115 dB sound pressure level for eight hours. The mean serum salicylate level just before noise exposure was 24 mg/dL (1.74 mmol/L). Ten days later they were killed, and the temporal bones were processed. Hair cell counts were made at 100-microns intervals throughout the length of the basilar papilla (cochlea). The noise produced a discrete cochlear lesion centered about 30% of the distance from the base to apex. The addition of aspirin did not significantly alter the extent or location of this lesion. One aspirin-fed chick had a unilateral middle ear effusion, and a striking shift in the center of damage toward the apex was noted in this cochlea.

Animals↗
PubMed1986

Oral steroid therapy for chronic middle ear perfusion: a double-blind crossover study.

A prospective, double-blind crossover study design was used in the evaluation of the role of prednisone in the treatment of a chronic middle ear effusion. Sixty children with an effusion--of at least 2 months' duration--randomly received either prednisone or placebo for 2 weeks. One week later they were re-evaluated. If the effusion had resolved, they were followed periodically; if the effusion persisted, they were given the crossover regimen and reevaluated. Sixty percent of the patients' effusions cleared, but there was no statistical difference between the prednisone and placebo groups. The amount of hearing recovery was also the same for both treatment regimens. Subdividing the patients on the basis of effusion duration, unilateral vs. bilateral effusions, or history of ventilation tubes or antibiotics failed to identify a subgroup of individuals who might benefit from a short-term course of oral steroids.

Administration, Oral↗
PubMed1986

Objective tinnitus in association with an abnormal posterior condylar emissary vein.

Objective, pulsatile tinnitus can often be related to an identifiable vascular abnormality. An unusual case of a massively enlarged posterior condylar emissary vein associated with pulsatile tinnitus in a young woman is reported. Initial evaluation of this patient with computed tomography revealed an enhancing mass near the posterior arch of the first cervical vertebra. An angiogram showed this to be large venous varix (posterior condylar emissary vein) arising from the distal sigmoid sinus. It drained down the neck, near the posterior arches of the cervical vertebrae. Slight digital pressure over the internal jugular vein effectively eliminated the tinnitus, presumably by altering flow dynamics through the condylar vein. The internal jugular vein was ligated, and this reduced the patient's tinnitus, which was no longer objectively audible. The anatomy of the posterior condylar emissary vein is discussed, and the general evaluation of a patient with objective, pulsatile tinnitus is reviewed.

Angiography↗
PubMed1985

Infralabyrinthine approach to skull-base lesions.

New surgical techniques have extended the head and neck surgeon's domain to include various skull-base lesions. The infralabyrinthine approach incorporates these techniques and can be used to resect benign and malignant tumors involving the base of the temporal bone. Lesions of the internal carotid artery near the carotid foramen are also readily accessible. The main surgical steps in the infralabyrinthine approach include (1) mastoidectomy, (2) anterior transposition of the facial nerve, (3) neck dissection, (4) removal of the lateral tympanic bone, (5) exposure of the jugular foramen, and (6) exposure of the intratemporal carotid artery. Details of the infralabyrinthine approach are illustrated by photographs of surgical and cadaver dissections. Examples of various lesions successfully treated by this technique are presented. The important surgical anatomy of the infralabyrinthine compartment of the skull base is reviewed, with particular attention paid to the internal carotid artery, which, like the facial nerve, demands an intimate familiarity on the part of the temporal bone surgeon.

Adult↗
PubMed1985

Delayed vertigo and profound sensorineural hearing loss.

Episodic vertigo, similar to that of Meniere's disease, can occasionally develop years to decades after an ear has suffered a profound sensorineural hearing loss. Although the pathogenesis of this process is unknown, it is theorized that delayed endolymphatic hydrops develops. An inflammatory reaction could cause obstruction of the endolymphatic duct or interfere with venous drainage from the region of the endolymphatic sac, leading to hydrops. This condition is reviewed, and two adult patients with severe episodic vertigo and a unilateral profound sensorineural hearing loss which occurred in childhood are presented. Their evaluation and management are discussed.

Adult↗
PubMed1984

High-resolution CT in the evaluation of glomus tumors of the temporal bone.

High-resolution computed tomography (HRCT) was performed in 33 cases of glomus tumors of the temporal bone and 10 cases of other tumors in and around the jugular foramen. HRCT helped to differentiate glomus tumors from vascular anomalies and from other benign or malignant lesions, and to determine the extent of deep involvement. It provided essential information for planning the surgical approach. When a lesion is large or appears atypical, complementary angiography is helpful. Otherwise, angiography may not be necessary.

Ear Neoplasms↗
PubMed1984

Fibrous dysplasia of the temporal bone: the use of computerized tomography.

Fibrous dysplasia of the temporal bone is a rare condition characterized histologically by proliferation of fibrous tissue with scattered trabeculae of immature bone. Eighteen cases of monostotic fibrous dysplasia of the temporal bone have been reported in the literature. The clinical course of temporal bone fibrous dysplasia is unpredictable. Potential complications include cholesteatoma, recurrence, and malignant transformation. Surgery has been the recommended treatment, but the indications, approach, and extent have not been clearly established. The introduction of computerized tomography with high-resolution bone reconstruction is a significant advance in the therapeutic approach to temporal bone fibrous dysplasia. It accurately defines the extent of the disease within the temporal bone, and periodic scanning will reveal any progression. This information can be used to resolve many surgical dilemmas and to minimize secondary complications. This article includes a comprehensive review of the literature on temporal bone fibrous dysplasia and summarizes a case in which computerized tomography was used.

Adolescent↗
PubMed1984

Facial paralysis in longitudinal temporal bone fractures: a review of 26 cases.

The management of facial nerve injury resulting from temporal bone fracture continues to be a topic of discussion. The indications for surgery as well as the proper timing and extent of surgical exploration are the principal questions debated. This study reviews a large series of patients (26), treated for facial paralysis following a longitudinal temporal bone fracture. The most frequent site of injury was the area of the geniculate ganglion. The injury to the facial nerve was often severe. We recommend early exploration in these cases when electrical studies indicate a severe injury. In most cases a combined mastoid and middle fossa approach is required.

Adolescent↗
PubMed1980

Pseudosarcoma of the larynx: a comprehensive analysis.

Pseudosarcoma of the larynx is a rare and controversial malignant neoplasm. The presence of a squamous cell carcinoma contiguous with an anaplastic-appearing spindle cell stroma constitutes the distinctive histopathologic appearance of this tumor. Laryngeal pseudosarcoma is most commonly seen as a polypoid glottic mass. Prognosis is best for this lesion and less favorable for sessile tumors and for supraglottic or hypopharyngeal involvement. The tumor demonstrates a biologic behavior similar to squamous cell carcinoma of the larynx, with local aggressiveness and metastatic capability to regional lymphatics and distant sites. Surgery is the treatment of choice, even for T1 glottic lesions, as radiation therapy is associated with a high local recurrence rate.

Aged↗
PubMed1977

Effect of exercise on perfusion of collateral-dependent myocardium in dogs with chronic coronary artery occlusion.

Since the ability of mature intercoronary collateral channels to increase myocardial blood flow in response to drug-induced coronary vasodilation has been questioned, the present study was undertaken to evaluate the response of coronary collateral circulation to the stress of exercise. Studies were performed at rest and during two levels of treadmill exercise in six dogs a minimum of 6 mo after placement of an Ameroid constrictor on the left circumflex coronary artery. Regional myocardial blood flow was estimated in normally perfused anterior and predominantly collateral-dependent posterior left ventricular wall with left atrial injections of radio-nuclide-labeled microscheres 7-10 mum in diameter. At rest, heart rate was 87 +/- 7 beats/min and mean myocardial blood flow was comparable in control and collateral-dependent regions (0.96 +/- 0.13 and 0.97 +/- 0.14 ml/min-g, respectively). During exercise, heart rates increased to 180 +/- 13 and 228 +/- 14 beats/min and myocardial blood flow (MBF) in the anterior control region increased linearly with heart rate (HR), (MBF = 0.133 HR - 0.202, r = 0.88). MBF to the posterior collateral-dependent region was similarly augmented during exercise (MBF = 0.140 HR - 0.252, r = 0.89), so that the linear correlation between HR and MBF was similar for the control and collateral-dependent regions. In addition, the transmural distribution of MBF was uniform at rest and during exercise in both the anterior control and posterior collateral-dependent regions. Thus, not only could the mature intercoronary collateral vasculature supply adequate flow at rest, but when subjected to the natural stress of exercise, the increase in flow to the predominantly collateral-dependent area was similar to that in the normally perfused area.

Animals↗
PubMedDate not supplied

Major congenital ear malformations: surgical management and results.

Fifteen patients with major congenital aural atresia underwent operations using an anterior (trans-atretic bone) approach. Facial nerve monitoring was used in all cases and there were no instances of facial nerve injury. Postoperatively, two thirds of the patients had speech reception thresholds of 30 dB or better; the air conduction threshold (averaged for 500, 1,000, and 2,000 Hz) improved at least 25 dB in 80% of the patients and at least 30 dB in 60% of the patients (follow-up, 10 to 29 months). Minor revision surgery was necessary in three patients. On the basis of this series, several conclusions were made. First, one of the most important factors in proper patient selection is the degree of middle ear development on computed tomography, both in terms of size and ossicular formation. Second, every attempt should be made to keep the ossicular chain intact (versus use of a prosthesis), as this appears to optimize hearing results. Third, embryologic considerations and surgical experience predict a mobile stapes in the majority of major atresias. Lastly, facial nerve abnormalities are to be expected, especially in patients with significant microtia, but facial nerve monitoring will help minimize the risk of facial nerve injury.

Adolescent↗
PubMedDate not supplied

A longitudinal study of changes in the cochlear nucleus in the CBA mouse.

The cochleas and brain stems of normal-hearing CBA/CaJ and CaH mice ranging in age from 1 to 18 months were examined by light microscopy to document normal age-related changes. At all ages examined, the cochlear morphologic structure appeared normal with no obvious loss of hair cells or spiral ganglion cells. In the cochlear nucleus, qualitative and quantitative changes were observed in the total nuclear volume, in globular cell size, and in neuronal packing density.

Aging↗