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Biomedical subjects

G T Tindall

Publications and source records attributed to G T Tindall.

At least 19 recordsLinked to original sources
PubMed1991

Pituitary adenoma: correlation of half-dose gadolinium-enhanced MR imaging with surgical findings in 26 patients.

Sellar magnetic resonance imaging studies obtained with half doses of gadopentetate dimeglumine (0.05 mmol/kg) were prospectively interpreted and retrospectively rated in 26 patients who subsequently underwent transsphenoidal sellar surgery for suspected pituitary adenoma. Studies included a sagittal scout view followed by a non-contrast-material-enhanced, an immediate postcontrast, and a delayed postcontrast T1-weighted image (obtained at 1.0 or 1.5 T). Ten of 11 confirmed microadenomas were identified prospectively; all were identifiable in retrospect. Macroadenomas (12 cases) were well demonstrated. The high signal intensity of the posterior pituitary and of intrasellar hemorrhage was obscured on postcontrast studies. Delayed images proved unnecessary. This prospective evaluation suggests that a half-dose study is comparable to retrospective studies in which full-dose techniques were used for detection of micro- and macroadenomas. Imaging times are reasonably short, and cost of contrast material is potentially reduced. Confirmation with larger studies is required, and careful endocrinologic and clinical follow-up of nonsurgical patients is necessary.

Adenoma↗
PubMed1990

Loss of vision after transsphenoidal surgery.

Eleven patients who experienced significant loss of vision after transsphenoidal surgery are reported on. The mechanisms involved in these visual complications include direct injury or devascularization of the optic apparatus, fracture of the orbit, postoperative hematoma, cerebral vasospasm, and prolapse of the optic chiasm into an empty sella. Factors that may increase the risk of visual complications include the presence of a pituitary macroadenoma, previous visual impairment, a "bottleneck" or dumbbell-shaped tumor, previous surgery and/or radiation therapy, and, possibly, use of a lumbar subarachnoid catheter during operation. A practical approach to the management and avoidance of these complications is presented.

Adenoma↗
PubMed1990

Cushing's disease: results of transsphenoidal microsurgery with emphasis on surgical failures.

From 1977 to 1988, 56 patients with a preoperative diagnosis of Cushing's disease were treated by transsphenoidal microsurgical exploration of the pituitary gland. In 42 patients, a discrete tumor was found and a selective adenomectomy was performed. Total hypophysectomy was performed in nine patients. In an attempt to preserve pituitary function, a technique of subtotal hypophysectomy was utilized in the remaining five patients. Regular and adequate follow-up results were obtained in 53 patients. A sustained remission was obtained in 45 of these 53 patients for a remission rate of 84.9%. Eight patients were classified as therapeutic failures. The causes for failure included: 1) invasive tumor; 2) hyperplasia mistaken for an adenoma; 3) a presumed ectopic source of adrenocorticotropic hormone; 4) misdiagnosis; 5) atypical tumor; and 6) recurrence of disease after remission. In cases of therapeutic failure, the original diagnosis of Cushing's disease must be reevaluated and treatment continued until sustained remission is achieved. Necessary measures to help avoid surgical failures and an approach for further diagnostic and therapeutic maneuvers in these cases are discussed.

Adrenalectomy↗
PubMed1990

Clinical aspects of lumbar intervertebral disc disease.

The diagnosis and management of lumbar disc disease has undergone significant changes in recent years. This is especially true for diagnostic imaging studies (MRI and CT). Currently, CT/myelography or unenhanced MRI may be used to confirm the diagnosis and the level of involvement of lumbar disc disease. The indications for lumbar disc surgery include patients with neurologic deficits and/or those in whom intractable pain does not respond to conservative measures. Conventional disc surgery and/or microdiscectomy are both good operative procedures for lumbar disc disease, and each yields excellent results when criteria for diagnosis and surgery are strictly followed.

Diagnosis, Differential↗
PubMed1989

Trends in neurosurgery. The 1989 AANS presidential address.

This overview of neurosurgical practice examines patterns of case management, using several areas such as head injury, brain tumors, and the delivery of health care to illustrate the changes that have taken place over the past 40 years and the changes that might be expected in the next 40 years. The rapid pace of progress has indicated further exciting growth of this specialty into the 21st century; however, what remains constant is the dynamic character of the neurosurgeon. This view of the past and the possibilities for future innovation enables neurosurgeons of all generations to have a sense of pride in the achievements generated by their peers.

History, 20th Century↗
PubMed1988

Rapid assessment of corticotropin reserve after pituitary surgery.

Corticotropin deficiency may occur after pituitary surgery, and, if unrecognized and untreated, it can be fatal. In this study the insulin tolerance test was used to assess hypothalamic-pituitary-adrenal reserve five to seven days after pituitary surgery, and postoperative morning serum cortisol concentration was compared with the insulin tolerance test for predicting corticotropin deficiency. In 35 patients with pituitary tumors studied prospectively, 27 had normal insulin tolerance test results five to seven days after pituitary surgery; in these patients, the morning serum cortisol concentration two to three days after surgery was 250 nmol/L (9 micrograms/dL) or greater. Eight patients had subnormal insulin tolerance test results or clinical evidence of adrenal insufficiency; the morning serum cortisol concentration in these patients was 80 nmol/L (3 micrograms/dL) or less. Postoperative adrenal insufficiency was transient (one to three months) in five of these eight patients. We retrospectively identified 45 patients whose postoperative morning serum cortisol values were 200 nmol/L (7 micrograms/dL) or greater; none of these patients had clinical evidence of adrenal insufficiency. We conclude that a morning serum cortisol level obtained two to three days after surgery and 24 hours after the discontinuation of hydrocortisone accurately predicts postoperative corticotropin reserve.

Adenoma↗
PubMed1988

Management of prolactinomas associated with very high serum prolactin levels.

The authors have reviewed the results of transsphenoidal microsurgical management in 69 patients with prolactin-secreting pituitary adenomas who had preoperative serum prolactin levels over 200 ng/ml. The patients were divided into three groups based on their preoperative serum prolactin levels: over 200 to 500 ng/ml (Group A); over 500 to 1000 ng/ml (Group B); and over 1000 ng/ml (Group C). The percentage of successful treatment ("control rate") was 68%, 30%, and 14%, respectively, in these three groups of patients. Based on these results, the authors offer guidelines for the management of patients with prolactin-secreting pituitary adenomas associated with exceptionally high serum prolactin levels. The surgical control rate of 68% in Group A seems to justify surgery for these patients, while primary medical care with bromocriptine is recommended for most patients with serum prolactin levels over 500 ng/ml.

Adenoma↗
PubMed1987

Pituitary tumors composed of adenohypophysial adenoma and Rathke's cleft cyst elements: a clinicopathological study.

Nine cases of pituitary tumors composed of mixed tissue elements of adenohypophysial adenoma and Rathke's cleft cyst are reported. All cases were associated with hyperprolactinemia and were managed by transsphenoidal adenomectomy with good results. The clinical and pathological features are presented, and embryological pathogenesis for the occurrence of this unique association is discussed in connection with the high incidence of immunoreactive S-100 protein cells identified in tumor tissues. Patients with this kind of pituitary tumor can be managed in the same fashion as patients with other types of pituitary adenoma.

Adenoma↗
PubMed1987

Ganglioglioma of the cerebellum: case report.

The authors report a rare case of a cerebellar ganglioglioma. A review of 12 previously reported cases and our case suggest that surgical removal of this neoplasm carries a good prognosis.

Adult↗
PubMed1987

Isolated histiocytosis X of the pituitary gland: case report.

The authors describe a case of a granuloma of histiocytosis X localized in the pituitary gland. The patient presented with diabetes insipidus and hyperprolactinemia. The diagnosis was established by surgical removal of the pituitary lesion through a transsphenoidal approach. The clinical and pathological aspects of the case are discussed.

Adult↗
PubMed1987

MR imaging of pituitary adenoma: CT, clinical, and surgical correlation.

Twenty-five patients with suspected pituitary adenoma were evaluated prospectively with CT and MR. Nine patients underwent transsphenoidal surgery, and three of these showed a documented decrease in size of mass on bromocriptine therapy. CT was more sensitive than MR for detecting focal lesions (seven vs three) and sellar-floor erosion (12 vs six). MR was superior to CT in identifying infundibular abnormalities (seven vs six), focal abnormalities of the diaphragma sellae (10 vs seven), cavernous sinus invasion (four vs two), and optic chiasm compression (six vs zero). Thus, MR may be the procedure of choice for optimal identification and localization of macroadenoma. For patients with suspected microadenoma, however, this preliminary series indicates that CT remains the radiographic procedure of choice.

Adenoma↗
PubMed1986

[Pituitary adenoma calcification].

Three hundred and eighteen cases of functioning and non-functioning pituitary adenoma were examined by histological, immunocytochemical and electronmicroscopic technique. Fourty-four of them (13.8%) showed evidence of calcospherites in the tumor tissues. A high incidence of calcospherite is found in functioning adenoma, but not in non-functioning adenoma. Calcification was seen most frequently in cases of prolactinoma (23), GH secreting (7), or GH + PRL tumor (2) and less in adrenocorticotropic hormone secreting adenoma (2) and follicle stimulating hormone secreting adenoma (1). Prolactin and growth hormone might be involved in the control of calcium metabolism. This is because, following adenomectomy in patients with prolactinoma or GH-secreting adenoma with hypercalcemia, there is normalization of serum PRL and GH with reduction in serum calcium. Calcospherite is produced in all of metastatic calcification, arterial calcification, dystrophic calcification and calcinosis. In cases of non-functioning adenoma however, the mechanism is believed to by dystrophic calcification.

Adenoma↗
PubMed1986

[A recurrent case of TSH-PRL secreting microadenoma following hypothyroidism].

A thirty-seven-year-old housewife whose chief complaints were recurrence of galactorrhea and amenorrhea three years after having a selective adenomectomy. Hormonal examination done as a result of the continuation of the endocrinism revealed a hyperprolactinemia and high level of TRH due to hypothyroidism. Serum prolactin responded to neither TSH stimulation nor L-Dopa suppression tests. In addition, serum TSH did not react to TRH test. Contrast enhancement CT showed an intrasellar enhancing mass the size of which was less than 1 cm in diameter. A unilateral septal transsphenoidal operation was performed; and a soft white-yellowish mass 7 X 5 X 5 mm in size was found in the left inferolateral aspect of the pituitary gland. Histological studies of frozen sections of this revealed it to be a pituitary adenoma, with the border between tumor and normal tissue being quite distinct. Immunocytochemical diagnosis further confirmed it to be both PRL and TSH producing adenoma. Electron microscopy showed more than three different hormone-producing cells. The PRL cells contained large, and the TSH cells had small hormone granules; but some tumor cells contained secretory granules of both sizes suggesting production of both PRL and TSH in the cytoplasm. It is necessary in the management of patients like this, during the post-operative period, to adequately institute a thyroid hormone replacement therapy so as to prevent recurrence.

Adenoma↗
PubMed1985

Symptomatic Rathke's cleft cysts located entirely in the suprasellar region: review of diagnosis, management, and pathogenesis.

Three cases of an entirely suprasellar symptomatic Rathke's cleft cyst, two of which were associated with normal sella turcicas, are reported. In all cases, the cysts caused compression of the optic chiasm, and two produced hypothalamic dysfunction. The diagnosis of these entirely suprasellar masses was enhanced by metrizamide cisternography. Two cases were treated by frontal craniotomy and one was treated transsphenoidally, with good results in all cases. The radiology, pathology, and surgical treatment of these unusual cases is presented. An embryological pathogenesis for the occurrence of an entirely suprasellar Rathke's cleft cyst is discussed.

Adolescent↗
PubMed1985

Prolactin-secreting pituitary microadenomas: inaccuracy of high-resolution CT imaging.

Computed tomographic (CT) and surgical findings were correlated retrospectively in 51 patients with preoperative diagnoses of prolactin-secreting pituitary microadenomas. Thirty-nine had microadenomas at surgery. Twenty-three had identifiable discrete lesions. Of these, 21 had microadenomas and two did not; these two groups could not be distinguished reliably. Six patients with proven microadenomas had normal CT scans. Focal hypodense lesions, sellar floor erosion, infundibulum displacement, gland height greater than 8 mm, and an abnormal diaphragma sellae configuration are neither sensitive nor specific findings of microadenoma. A significant number of patients with proven microadenomas had few or none of these abnormalities. Thus, recognition of prolactin microadenoma may not be possible by CT alone, even with high-resolution direct coronal imaging.

Adenoma↗