Search PubMed⌕ Search

Biomedical subjects

C G Jackson

Publications and source records attributed to C G Jackson.

At least 73 records · Page 4Linked to original sources
PubMed1990

Scalene muscle abnormalities in traumatic thoracic outlet syndrome.

Thoracic outlet syndrome (TOS) is not a single disorder but a collection of abnormalities in the same anatomic area that elicit similar symptoms. The many causes of TOS are best classified into one of three groups: osseous, traumatic, and nontraumatic. Although patients with traumatic TOS constituted 86% of our last 600 patients with TOS who underwent surgical treatment, the precise mechanism underlying the condition remains obscure. To determine if there was microscopic abnormalities, 45 anterior and middle scalene muscles from patients with traumatic TOS were studied by means of histochemical stains applied after freezing of the muscles. The results revealed a consistent abnormal histologic pattern in patients with traumatic TOS: type II fibers were atrophied; there was an increase in the average number of type I fibers (78% versus 53% in muscles from control patients); and there was a significant increase (mean: 36%) in connective tissue (muscles from control patients averaged less than 15%). Although type II fiber atrophy and type I fiber predominance are seen in a variety of other conditions, their association with fibrosis is rare. Following neck injuries, the changes in the anterior and middle scalene muscles are compatible with trauma, suggesting that fibrotic scalene muscles are an important cause of symptoms in traumatic TOS.

Adult↗
PubMed1990

Diagnosis and management of paragangliomas of the skull base.

In appropriately selected patients, glomus tumors of the head and neck are best treated surgically. Unresectability is not a factor in therapeutic planning for local disease control. Existing techniques and exposures for tumor removal can be reliably applied to these paragangliomas, with acceptable morbidity and mortality. A team approach to this problem is mandatory.

Adult↗
PubMed1990

Liver histology in patients receiving low dose pulse methotrexate for the treatment of rheumatoid arthritis.

The liver histology of 52 patients treated with intermittent low dose pulse methotrexate for rheumatoid arthritis was evaluated using a modification of the Roenigk grading system. Patients studied had had an average of 3.2 years of treatment or had received 1.7 g methotrexate. No patient had cirrhosis; 15 (29%) patients had evidence of mild fibrosis. Histological abnormalities were not predicted by liver function test changes, with the exception that hypoalbuminaemia occurred in 60% of those with grade IV (modified criteria) findings. The need for liver biopsy in patients with rheumatoid arthritis treated with methotrexate before two years or 1500 mg of treatment has not been established. Whether serial liver biopsies will be needed beyond this time has yet to be determined.

Adult↗
PubMed1990

Pathologic findings in the labyrinthine segment of the facial nerve in a case of facial paralysis.

The histopathologic findings for a patient with acute facial paralysis caused by herpes zoster oticus who obtained no return of active facial function after 1 year are presented. All imaging studies were nondiagnostic. Biopsy of the labyrinthine segment was performed. Histopathologic analysis showed a sharp line of demarcation between sclerotic nerve proximal to and necrotic nerve distal to the meatal foramen area of the fallopian canal. This finding is consistent with observations that the lesion producing Bell's palsy and herpes zoster oticus usually is situated at the meatal foramen.

Adult↗
PubMed1990

Acoustic neuroma: a cost-effective approach.

A cost-effective approach to the diagnosis and treatment of acoustic neuromas continues to evolve as diagnostic methods improve. In the past 7 months, since gadolinium-enhanced magnetic resonance imaging (MRI) has become available in our practice, our screening and presurgical workup has changed. The purpose of this article is to outline the current philosophy of the senior authors in relation to acoustic neuroma management on the basis of 72 patients diagnosed from July 1988 to February 1989. With more sensitive diagnostic means, older less sensitive studies may be eliminated from the routine workup, thus maintaining cost-effectiveness while preserving the highest standard of patient care. The body of this article will review our current use of the many available diagnostic options and emphasize a cost-effective approach.

Adult↗
PubMed1990

Management of large dural defects in skull base surgery: an update.

The use of a ventriculoatrial shunt for long-term CSF diversion for reconstruction after resection of large skull base tumors with intradural extension has been discontinued. The concern about placing a permanent foreign body in a wound open for 12 to 18 hours is our primary reason for changing the technique. Our present approach uses a rectus abdominis microvascular free flap over the fascial closure of the dural defect. Although our experience with this technique is limited, the advantages over the technique used previously warrant its continued use.

Abdominal Muscles↗
PubMed1990

Conservation surgery for glomus jugulare tumors: the value of early diagnosis.

The results of lateral cranial base surgery for glomus jugulare tumors are gratifying when normal anatomy and function can be preserved. The goal of conservation surgery is to preserve normal ear anatomy and cranial nerve function. In general, conservation surgery is tumor-size dependent. Thus, excellent states of functional recovery depend upon accurate early diagnosis. This paper reviews the technical aspects of transtemporal conservation skull base tumor surgery while also reviewing our experience with nearly 100 glomus jugulare patients. Adjuvants to early diagnosis will be highlighted from a review of presenting symptoms, clinical signs, and related diagnosis. Our objective is to provoke a high index of suspicion in physicians charged with the responsibility of diagnosing these tumors. Diagnostic guidelines are proposed.

Deglutition Disorders↗
PubMed1990

Recurrent hemangioma of the external auditory canal.

Hemangiomas of the external auditory canal rarely occur. These lesions have been reported to involve men in their sixth decade. This case report represents the fourth such lesion reported in the literature and the first to be seen in a woman. The clinical presentation, surgical therapy, and pathology are discussed. This tumor represents an unusual cause of hearing loss.

Ear Canal↗
PubMed1989

A paraneoplastic syndrome associated with glomus tumors of the skull base? Early observations.

Independent secretion of vasoactive substances by glomus tumors of the skull base is widely recognized. Surgical removal of these tumors often results in an unexplained prolonged postoperative ileus, even in cases in which the vagus nerve is preserved. There is evidence that these tumors may secrete neuropeptides, such as cholecystokinin, in addition to catecholamines. A retrospective analysis of cases of glomus tumors of the skull base operated on at The Otology Group was carried out to correlate preoperative neuropeptide levels, vagus nerve status at surgery, and duration of postoperative ileus. High circulating levels of cholecystokinin associated with these tumors may be responsible for the unexplained phenomenon of prolonged postoperative ileus. The relevance of neuropeptides to the postoperative management of these patients is discussed. Preventive measures that may avert the potentially lethal complications of aspiration and negative nitrogen balance are described.

Catecholamines↗
PubMed1989

Management of bilateral acoustic tumors.

Bilateral acoustic tumors (Neurofibromatosis 2) have now been shown to arise in patients with gene abnormalities separate from those with von Recklinghausen's disease (Neurofibromatosis 1). The management of patients with this disease has long posed a particularly challenging problem for the neurotologist. This retrospective study reviews our series of 38 patients and updates a previous report. Thirty-four patients underwent surgical excision of tumors on one or both sides. Hearing conservation was attempted in 20 with hearing preservation possible in eight. Recent advances in understanding the hereditary etiology of this disease, changing methods for diagnosis, preferred surgical techniques, and guidelines for appropriate patient management are discussed.

Adult↗
PubMed1989

Glomus tympanicum tumors: contemporary concepts in conservation surgery.

The management of glomus tympanicum tumors is not a new subject. A review of the contemporary management concept is, however, needed for two reasons: 1. the recent literature has suggested radiation therapy as a treatment option in this surgical disease, and 2. patients who are referred to us for management of these tumors continue to exhibit errors in diagnosis and surgical approaches that are unnecessarily radical. The purpose of this paper is to review the diagnosis of these lesions and to prospectively differentiate them from the more extensive jugulare tumors. When type and extent of the tumor are properly determined, a surgical procedure can be planned that conserves as much normal ear anatomy and function as possible. Between May 1970 and July 1988, 60 patients with glomus tympanicum tumors were treated at the Otology Group, P.C., in Nashville, Tennessee. In 47 patients (78%), the tumors were removed using an extended facial recess approach. The external auditory canal wall was removed in seven patients (12%), and six patients underwent a transcanal approach. Total tumor removal was obtained in 90% of patients. Surgical management remains the mainstay of treatment for glomus tympanicum tumors.

Adult↗
PubMed1989

What I think of sac surgery in 1989.

The senior author has performed shunt procedures routinely for medically refractory cases of Meniere's disease starting in 1964 and ending in 1984. Five hundred and sixty-eight consecutive patients were operated on and followed from 1970 to 1984. Combining the cases of C. G. Jackson, there have been a total of 676 procedures done at the Otology Group. Initially endolymphatic-subarachnoid (ES) shunts were used, then endolymphatic-mastoid shunts (EM), and most recently, the Denver valve has been employed. No significant difference between these procedures was noted in the control of vertigo or stabilization of hearing. Successful resolution of vertigo occurred in less than 60%. Sac surgery at the Otology Group, therefore, has been abandoned in favor of vestibular nerve section for the surgical management of medically refractory Meniere's disease with disabling vertigo.

Ear, Inner↗
PubMed1988

Can acquired immunodeficiency syndrome and Creutzfeldt-Jakob disease be transmitted via otologic homografts?

Materials commonly employed in the preparation of otologic homografts such as ethanol and formaldehyde are effective in vitro in inactivating human immunodeficiency virus (HIV). However, to our knowledge, the complete permeation of homograft materials with preservative has not been demonstrated. Ethanol and formaldehyde have not been shown to be effective in inactivating the Creutzfeldt-Jakob agent. The literature on sterilization procedures for these agents is reviewed. Standard procedures for preparation of otologic homografts are examined. It is recommended that donor HIV serologic status be determined when otologic homografts must be used. Further research is required to determine the efficacy of otologic homograft sterilization techniques against HIV and Creutzfeldt-Jakob disease.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Endolymphatic mastoid shunt surgery using the Denver inner ear shunt.

This study, merging data from two different clinics, was undertaken to evaluate the efficacy of endolymphatic mastoid shunt surgery using the Denver Inner Ear Shunt operation for Meniere's disease. This surgery was performed by the senior authors (C.G.J., J.R.E.D., and M.E.G.) between May 1984 and October 1986, after we attended the Colorado Otologic Research Center (CORC) instructional course. Sixty-six and thirty-four cases, respectively, were performed. Follow-up questionnaires were sent to this total of 100 patients. Fifty-six patients returned completed questionnaires, which formed the basis of this report. A retrospective chart study was also carried out. The results of surgery and questionnaires are reported as statistical data, and, where applicable, the 1985 AAO-HNS criteria for reporting vertigo and hearing results in the treatment of Meniere's disease are used. Preliminary analysis of these data is reported because of its profound effect upon our treatment protocol for patients with Meniere's disease. Results on use of the Denver valve do not appear to be significantly different than the results of other shunt surgery not using the valve.

Adolescent↗
PubMed1988

Antimicrobial prophylaxis in ear surgery.

The purpose of this research was to assess the efficacy of prophylactic antibiotic administration in ear surgery over a wide range of cases. Additional objectives include the assessment of the relative effect of patient age, duration of operation, preoperative condition, and the success of tympanoplasty. Prospectively, in a controlled study, 4,000 patients were studied employing cephalosporin and oxacillin as prophylactic antimicrobials. No statistically significant difference in postoperative otologic infection rates was observed. This conclusion was unaltered by the operative duration, patient age, or preoperative condition. Grafting success was not improved.

Adult↗
PubMed1988

Altitude, training and human performance.

The effect of altitude on human performance is complex. Numerous variables are known to change from sea-level measures. Maximum aerobic power is depressed as ascent occurs and this impairs the ability to work maximally. While changes in haematological variables would theoretically counterbalance the loss in aerobic power, they have not been shown to do so. The environmental stress of cold may have positive effects on aerobic capacity at altitude, but this has been little investigated in humans. Pulmonary ventilation increases with altitude and the measure of hypoxic ventilatory response holds some promise of predicting humans who may benefit from altitude conditioning. Cardiac function is well maintained while lung function is not. The preferred fuel for exercise at altitude seems to be fat, while carbohydrate metabolism is dramatically changed. Much is not known of high altitude anorexia and muscle mass loss. Conditioning at altitude is known to benefit performance at altitude. The evidence for a sea-level benefit from altitude training as yet remains elusive. While selected individuals may benefit, the reasons why have not been determined.

Altitude↗
PubMed1987

Primary adenocarcinoma of the middle ear and temporal bone.

Primary adenocarcinoma of the temporal bone is a rare disorder. Fewer than 40 cases have been reported in the English literature, most of these being single case reports. Exclusion of metastatic adenocarcinoma is imperative. Adenocarcinomas must be differentiated from benign adenomas. Adenocarcinomas are best managed by aggressive surgical resection, with postoperative irradiation used in cases of incomplete resection or high-grade tumors.

Adenocarcinoma↗