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Biomedical subjects

L W Welsh

Publications and source records attributed to L W Welsh.

At least 19 recordsLinked to original sources
PubMed1998

Current evaluation of pseudohypacusis: strategies and classification.

Some cases of pseudohypacusis may involve medicolegal aspects and require a confirmed and quantitative diagnosis. These challenging cases must be identified, and then evaluated with basic audiologic and sophisticated electrophysiologic tests. Data on 64 patients with pseudohypacusis collected over a 4-year period are reported. A classification system was developed from an analysis of these cases and is presented for clinical evaluation and diagnosis. In many cases, conventional audiologic evaluation involving pure tone and speech audiometry may be adequate and sufficient for diagnosis. In more complex cases, evoked otoacoustic emissions (EOAEs) and auditory brain stem responses (ABRs) are needed for confirmation of peripheral auditory sensitivity. We found that EOAEs were the most rapid economical, and objective method, and confirmed the diagnosis of hearing loss in 78.1% of cases. Fifteen percent of subjects required ABRs to substantiate the diagnosis. The reliability of basic audiologic tests based on previous clinical investigations and data from the literature are discussed. We conclude that a thorough knowledge and understanding of pseudohypacusis is essential to verify the existence of pseudohypacusis, to determine its type, and to quantify the auditory thresholds.

Acoustic Stimulation↗
PubMed1996

Evaluation of the vestibular system by magnetic resonance angiography.

This report describes the normal arterial patterns of the vestibulocerebellar regions visualized by magnetic resonance angiography. Variations in the vertebrobasilar arterial system are described, limitations in imaging are discussed, and collateral connections within the cerebellar vessels and the circle of Willis are reviewed. Clinical correlations are defined between the vestibular nuclei, the associated intraaxial tracts, and with specific posterior cerebral and brain stem arteries.

Basilar Artery↗
PubMed1996

Syndromal vertigo identified by magnetic resonance imaging and angiography.

The advent of magnetic resonance imaging and angiography has clarified the location and vascular basis for vertigo of a syndromal type. The composite presentation of a vestibular symptom with evidence of cranial nerve or cerebellar dysfunction suggests a lesion within the pons, medulla, or cerebellum. The location may be exactly defined by noninvasive techniques and appropriate therapy can be initiated. Clinical examples are presented; the syndromes of vertebrobasilar artery perfusion disorder are described, and appropriate images are illustrated for confirmation.

Adult↗
PubMed1996

Learning disabilities and central auditory dysfunction.

Hearing loss, whether peripheral or central, compounds the communication and educational problems of the learning disabled student. A central auditory processing disorder uniquely interferes with both the input and integration of verbal information, further resulting in a potentially permanent cognitive dysfunction during the developmental period of acquisition of language. Illustrative cases are presented that indicate the panorama of cognitive dysfunction associated with the learning disabled status. Methods of evaluation and identification and diagnostic criteria are correlated with auditory, visual, and academic performance. Comments regarding clinical awareness, prompt recognition, and ensuing individualized remediation are submitted.

Adult↗
PubMed1996

Early sound deprivation and long-term hearing.

The long-term effects of hearing loss in early life were analyzed by tests of central auditory function. A majority of individuals failed the Compressed Speech identification with statistically significant results. There was an impact on a minority of individuals evaluated by Dichotic Sentences; little impairment was noted through Speech Reception in Noise. Delayed maturation of the central auditory complex may improve these findings, although during the period of investigation a negative impact was measured. Other issues of diagnosis, remediation, and the consequences of short- and long-term deafness are discussed.

Adolescent↗
PubMed1992

Radiographic analysis of deep cervical abscesses.

Correlation of the radiographic examination and the clinical evaluation of deep cervical abscesses contributes to the surgical program for exposure and drainage. The deep cervical spaces are analyzed with reference to local anatomy, sources of infection, potential for lateral and vertical extension, and identification of regional expansion by standard and computed tomography. Guidelines and recommendations are proposed for clinical application and supported by illustrative cases.

Abscess↗
PubMed1991

Massive orofacial abscesses of dental origin.

Massive cervicofacial abscesses of dental origin are relatively rare, and may be associated with serious and grave morbidity. In extreme cases, an occasional fatality may result from regional complications. Three cases are presented that describe the clinical and radiographic evaluation and the surgical approaches for abscess drainage. Specific attention is directed toward 1) the management of imminent airway obstruction, 2) the application of computed tomographic technology for localization and surgical planning, and 3) current antibiotic therapy.

Abscess↗
PubMed1990

Role of angiography in the management of refractory epistaxis.

When interruption of the related arteries fails to control epistaxis, angiography is recommended for identification of the vascular base, the collateral circulation, and the possibility of arterial abnormalities. Criteria are proposed for utilization of vascular mapping, and relevant cases are cited to support the specific indications for application.

Aged↗
PubMed1989

Internal anatomy of the larynx and the spread of cancer.

This project investigated the potential spread of cancer within the larynx by an analysis of the permeability and resistance of the subepithelial spaces. Permeation and diffusion of dye injections in the loose connective tissues below the epithelium was analyzed by histologic preparations in the sagittal plane. The margins of the infusion were identified grossly and microscopically, and the influence of the fibrous, elastic, and muscular components was analyzed with reference to the dispersion of the dyes. A close correlation between laboratory data from normal postmortem larynges and clinical problems of laryngeal cancer was observed in this study.

Adult↗
PubMed1989

Endoscopic problems due to cervical vertebral diseases.

The authors draw attention to cervical spine disorders that limit mobility of the vertebrae and thereby interfere with esophagoscopy. Four orthopedic disorders that either fuse the cervical spine or produce massive osteophytes are discussed and exemplified by specific cases, and appropriate techniques for endoscopy are recommended.

Aged↗
PubMed1985

Central presbycusis.

The phenomenon of central presbycusis has been investigated employing a central auditory battery in elderly individuals with essentially normal hearing. The studies indicate a progressive loss in central auditory competence measured by simultaneous binaural challenges and frequency and temporal distortion tests. The rate of failure is related to age, on the whole, but there is increasing variability from the normals with seniority. The hearing disability in noise or speech competitive environments is explained by these data. Auditory disabilities related to poor articulation and rapid speech presentation are identified by other tests in the battery. Central presbycusis, in addition to the peripheral form, does exist and further compounds the hearing disorder in many elderly.

Age Factors↗
PubMed1983

Effect of sound deprivation on central hearing.

The authors have investigated the thesis that intermittent hearing impairment due to middle ear disease in the early years of life results in a central auditory disturbance which may persist in adulthood. The concept that, during the speech development years, auditory disturbances interfere with the normal maturation of central auditory processing appear to be clearly established. Thirty-five children, free of active ear disease and normally hearing by standard peripheral audiometry, are the basis for the study. The monotic tests employing temporal and frequency distortion and the dichotic challenges of competing stimuli and central integration provide the test data. Approximately 75% of the study group fail at least 1 segment of the battery, beyond 2 standard deviations from the normal data. A decreasing percentage of the study group exceed the normative values in 2 or more of the test components. In view of these data on aggressive program of auditory conservation is suggested during the early years of life.

Auditory Perceptual Disorders↗
PubMed1980

Central auditory testing and dyslexia.

A group of dyslexic pupils with normal end organ function was studied by a central auditory battery to determine whether a hearing disability existed. The clinical features of dyslexia are presented with emphasis on the psychological developmental and functional disorders associated with this reading problem. The central battery of Willeford was selected as the test medium and the results of the 77 dyslexic students were compared to the normative data. The model proposed by Sparks, et al., is accepted as the mechanism for dichotic audition. Reference is made to the organic basis of reading disorders from lesion in the calcarine area to the angular gyrus. The competing sentence test, binaural fusion, rapidly alternating speech perception, and filtered speech are described in detail and are organic foundation for the study. The authors indentified a high rate of failure in this investigation. Over 50% of the dyslexic students failed two of the four tests, and each of the 77 failed at least one component. The most sensitive tests were binaural fusion and filtered speech with less variation from the norm in the remaining two components. The effect of maturation in central audition was measured in each of the four tests. The data suggest: 1. the scores are lower in the early ages in each test; 2. that rapidly alternating speech and competing sentences approach the normal range albeit somewhat delayed; and 3. that binaural fusion and filtered speech improve in score somewhat but rather moderately and never approach the normal range. Based upon the central auditory data and in conjunction with the anatomical pathways of vision, the authors suggest the site of lesion to be in the temporo-parietal cortex and the association fibers.

Adolescent↗
PubMed1978

Endoscopic examination of corrosive injuries of the upper gastrointestinal tract.

The authors present the case histories of five patients who have sustained corrosive injuries of the upper gastrointestinal tract. Flexible endoscopic examination was successfully carried out in each patient to assess the extent of the injury and anticipate further therapeutic needs. Three patients sustained major gastric lesions, i.e., strictures or bleeding following the ingestion of alkali, acids, or phenol, and one instance of esophageal stricture was recognized. The endoscopic observation of antral gangrene was inexorably followed by antral stricture requiring surgical management. One fatality followed rigid esophagoscopic examination which resulted in esophageal perforation.

Adult↗
PubMed1977

Problems of diagnosis in the evaluation of mediastinal sarcoidosis.

The diagnosis of sarcoidosis can be established when the case meets the criteria of clinical course, radiologic findings, and supportive histology. When there is variation from the established criteria and the clinical course of age, systemic evidence of disease or the radiologic findings of unilateral or solitary adenopathy are encountered, then ongoing evaluation is necessary to identify a possible second disease existence. Cases have been presented which indicate some problem requiring further investigative studies before acceptance of the diagnosis of sarcoidosis.

Adult↗
PubMed1976

Glomus jugulare tumor. Disseminated form in the central nervous system.

We will describe a case of glomus jugulare tumor that illustrates the potential for multiple areas of metastasis throughout the central nervous system. Extension through the dura into the subarachnoid space allows seeding via the cerebrospinal fluid as far away as the cauda equina. We will review the usual clinical course of the tumor and will evaluate the symptoms relative to the location of extension. In this case, the symptoms related to increased intracranial pressure with brain stem compression, which progressed rapidly to cause the patient's death.

Autopsy↗