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Biomedical subjects

R Fahlbusch

Publications and source records attributed to R Fahlbusch.

At least 217 records · Page 12Linked to original sources

Intrasphenoidal encephaloceles--a clinical entity.

In the current classification basal encephaloceles are grouped together with real transsphenoidal encephaloceles. But those encephaloceles extending only into but not through the sphenoid sinus seem to represent a specific clinical entity and therefore should be regarded as a rare subgroup of sphenoidal encephaloceles. One personal case and six cases from the literature are reviewed, the own case being associated with an empty sella turcica. The initial sign is rhinorrhea, almost invariably. The association with other intracranial anomalies is uncommon. The extradural transsphenoidal or transethmoidal midline approach accompanied by a shunting procedure today is the most suitable method of surgical treatment.

Adult↗

Corticotropin-releasing hormone stimulation test before and after transsphenoidal selective microadenomectomy in 30 patients with Cushing's disease.

Thirty patients with ACTH-dependent Cushing's disease were tested with CRH before and 7-10 days and 3-6 months after selective transsphenoidal adenomectomy. In 28 of 30 patients an adenoma was found, and in 22 (79%) clinical and endocrinological remission occurred. Preoperatively, the majority of the patients had basal and CRH-stimulated plasma ACTH levels that were markedly increased compared to those in normal subjects. On the basis of the CRH stimulation test and low dose (2 mg) dexamethasone suppression test results 7-10 days after surgery, these 30 patients were divided into 4 groups. Groups I, II, and III were patients in remission, as defined by undetectable, subnormal, or normal basal plasma ACTH and cortisol levels in addition to sufficient suppression of cortisol (less than 2 micrograms/dL) during the low dose (2 mg) dexamethasone suppression test. Patients in group IV were not in remission. In group I (n = 6), CRH failed to raise undetectable basal ACTH levels in the early postoperative period; however, 3-6 months later plasma ACTH did increase in response to CRH. In group II (n = 11), undetectable or low basal ACTH levels increased after CRH, and the increase was similar to that in normal individuals. In group III (n = 5), basal ACTH levels were normal, and the response to CRH was exaggerated, but all patients responded normally to the dexamethasone suppression test. The CRH-induced ACTH increase in group III was significantly greater (P less than 0.003) than that in normal subjects, but was similar to that in patients not in remission in group IV (n = 6). Three to 6 months later, the ACTH response to CRH in group III was normal. In summary, the CRH test 7-10 days after surgery in patients with Cushing's disease indicated remission when there was no CRH-induced ACTH response or the response was normal (groups I and II). The test failed to predict remission in patients with an exaggerated CRH-induced ACTH response (groups III and IV). However, with regard to group II, the CRH-induced ACTH increase 1 week after selective adenomectomy indirectly supports the concept of CRH deficiency during hypercorticism and thus, in these patients as well as in group I, a pituitary origin of the disease.

Adenoma↗

Are flash-evoked visual potentials useful for intraoperative monitoring of visual pathway function?

Flash-evoked visual potentials (VEPs) recorded from the scalp were used in a series of 35 patients with tumors along the visual pathway: 3 orbital tumors, 25 perisellar tumors, 4 intraventricular tumors, and 3 occipital lesions. Preoperatively, various combinations of impaired visual fields and visual acuity were observed in over 90% of the patients. A postoperative decrease in visual function was observed in 3 cases. Of the 25 perisellar lesions, 13 were operated through a standard frontotemporal craniotomy and 12 were operated through a transnasal-transsphenoidal approach. VEPs were highly susceptible to volatile anesthetics, and there was a significant incidence of spontaneous latency increases and amplitude decreases in a large number of patients. There was an unacceptably high number of cases with significant VEP alteration occurring without concomitant visual function change. During trepanation or the transnasal approach, a reversible potential loss was observed in 11 patients, a profoundly altered wave form was seen in 8 cases, and a loss of single peaks was observed in 15 patients. During dissection of the tumor, a reversible potential loss or a potential with unidentifiable peaks was found in 25 cases; however, the VEPs recovered during closure or in the recovery room. There was no correlation between intraoperative VEP changes and the postoperative changes in visual function. In only 1 patient with an insignificant postoperative decrease in visual acuity from 0.4 to 0.3 was there a concomitant intraoperative potential loss. The major conclusion of our findings is that light-emitting diode flash-evoked VEPs demonstrate intraoperative changes that appear too early and too prominently to be caused solely by manipulation of the optic pathways.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Short-term preoperative treatment of macroprolactinomas by dopamine agonists.

During a period of 3 years, 25 patients with intra- and extrasellar macroprolactinomas were pretreated with dopamine agonists for a period of 2 to 6 1/2 weeks prior to transsphenoidal microsurgical tumor resection. Dopamine agonists were administered orally to 17 patients, intramuscularly to three patients, and both orally and intramuscularly to five patients. Repeated computerized tomography (CT) examinations revealed that all neoplasms except one cystic tumor were reduced in size during the course of dopamine-agonist administration. No complications attributable to medical pretreatment were observed. Tumor shrinkage increased the efficacy of surgery, especially in cases with considerable extrasellar extension of the adenomas. Within 3 months following adenomectomy, prolactin levels were adjusted to normal levels in 19 patients by additional low-dose treatment with dopamine agonists. Thin-collimation CT assessments performed at least 3 months after surgery showed no evidence of residual tumor tissue in 23 patients. It is concluded that administration of dopamine agonists for some weeks prior to surgery is a useful adjunct to transsphenoidal microsurgery for macroprolactinomas. The new injectable form of bromocriptine is particularly valuable for this purpose.

Adenoma↗

[Psychopathologic symptoms and personality traits in patients with florid acromegaly].

Important technical and clinical progress has been achieved in neuroendocrinological diagnostic investigations in recent years. Patients with active acromegaly and without a total loss of pituitary anterior lobe function can now be defined. With the help of neuroradiological investigations the intra-, supra- and parasellar extent of the adenoma can be determined. For the following study we selected patients with active acromegaly without a significant reduction of the other pituitary anterior lobe functions and with intrasellar adenomas. 31 patients with active acromegaly were examined before the operation. These patients have uniform psychopathological symptoms including loss of drive, affective disorders such as dejection, brooding, and irritability, and increase in appetite and loss of libido. The psychopathological symptoms are dependent neither on the level of the increased growth hormone nor on hyperprolactinemia. The higher cortical functions are intact. No disorders of intelligence or memory can be found. Disturbances of mental functions are manifested as disorders of concentration and fatigue. Personality traits were strikingly uniform. Their personalities are characterized by conscientiousness, reliability and industriousness. Some patients are also anxious and lacking in self-confidence. The personality traits of the patients become more pronounced as a result of the illness. The continuous development of the patients corresponds to the personality traits. Changes in personality, in particular those caused by organic brain disease were not found. Because we applied strict criteria to the selection of our patients we conclude that the uniform psychopathological symptoms and the uniform personality traits of the patients are an essential element of the clinical picture of active acromegaly.

Acromegaly↗

CRH test after pituitary microsurgery suggests tertiary adrenocortical insufficiency in successful operated patients with Cushing's disease.

In this study 30 patients with ACTH-dependent Cushing's disease underwent CRH-stimulation test before, 7-10 days and 3-6 months later after transphenoidal selective microadenomectomy. In 22 of 30 patients clinical and endocrinological remission (2 mg dexamethasone suppression test below 2 micrograms/dl cortisol) occurred. Fourteen of the 22 patients in remission showed a statistically significant increase of ACTH after CRH, 1 week after the operation. This CRH-induced ACTH increase in the early post-operative period gives indirect evidence for endogenous CRH deficiency and suggests tertiary adrenocortical insufficiency in successfully operated patients.

Adenoma↗

[TRH-stimulated growth hormone secretion in acromegaly. Therapeutic results with 188 patients].

TRH-induced stimulation of hGH secretion before and after operation or radiotherapy and during bromocriptine treatment was tested in 188 patients with acromegaly. A normal hGH level (basal level less than 5 ng/ml) was achieved after operation in 106 patients (58%). Postoperatively persisting elevated hGH levels were reduced to normal by bromocriptine in 39%, by radiation in 22% and by combined radiation and bromocriptine in 48%. In cases with additional hyperprolactinaemia a response to bromocriptine occurred in 47%. Pre- and postoperative TRH-induced stimulation of hGH secretion was not correlated with the rate of either normalization nor recurrence and thus has no prognostic significance.

Acromegaly↗

True precocious puberty of a girl with hamartoma of the CNS successfully treated by operation.

A girl with precocious puberty due to a hypothalamic hamartoma is presented. At the age of 0.41 years vaginal bleeding was documented and signs of puberty were noted: PHIII, BII according to Tanner. The bone age was 1.3 years, and height velocity rose from the 50th to 90th percentile. Plasma concentrations of LH (5.85 mU/ml), FSH (3.29 mU/ml), growth hormone (30 ng/ml), and oestradiol (90 pg/ml) were elevated. The results of a neurological examination including an EEC recording as well as a skull roentgenogram, were unremarkable. The visual evoked potentials were grossly abnormal. A native and contrast CT scan visualized a tumour close to the suprasellar cisterna reaching the chiasma opticum. At the age of 1.2 years the tumours was removed. Histologically the tissue was identified as a hamartoma. Immediately after the operation vaginal bleeding ceased, pubertal development regressed, bone age did not advance any further, the visual evoked potentials normalized and the contrast CT did not show any tumour mass. The levels of LH, FSH, growth hormone and oestradiol 4 months post operation were decreased as follow: LH: 1.14 mU/ml, FSH: 0.70 mU/ml, GH: 15.1 ng/ml, oestradiol: 10 pg/ml. However, there was an increase of FSH (3 mU/ml) 1 year after the operation. No secondary sexual characters reappeared.

Estradiol↗

Simultaneous estradiol and progesterone receptor analysis in meningiomas.

The availability of [125I]estradiol and [3H]R5020, a synthetic gestagen, have made it possible to determine estradiol and progesterone receptors simultaneously in 70 meningiomas with a double-labeling assay. With this technique, complete Scatchard analysis can be carried out for both receptors, even with small amounts of tumor tissue such as biopsy specimens. Low levels of estradiol receptor reactivity were found in 11%, whereas specific progesterone receptors were demonstrated in 76%, of the meningiomas examined. No correlation of receptor concentration with sex or age of the patients or with location of the tumor has yet been demonstrated. However, indications of a correlation between gestagen binding activity and histological subtypes were found. The presence of progesterone receptors in a large proportion of meningiomas could have implications for tumor therapy.

Female↗

[Analysis of estradiol and progesterone receptors in meningioma].

65% of all intracranial meningiomas and 80% of the intraspinal ones are seen in women. Meningiomas often grow larger and present an increased incidence of clinical signs and symptoms during pregnancy and also in the luteal phase of the menstrual cycle. In this study the oestradiol and progesterone receptors were determined in 30 patients for the first time via the double ligand assay. In about 10% of the patients we found slight oestradiol receptor activity, whereas approx. 63% of the meningiomas examined had specific progesterone receptors. So far there has been no evidence of a definite dependence of receptor concentrations on the sex and age of the patients or on the pathohistology and site of the tumours. Results can be compared with the previously published data on oestradiol and progesterone receptors in meningiomas to a limited extent only, since different biochemical techniques have been employed and also since pre-operative glucocorticoid treatment has been different from study to study. However, we can safely assume that a specific progesterone receptor does exist. Since proliferation of meningiomas with high concentrations of circulating gestagens has been established, the occurrence of significant concentrations of progesterone receptors could imply therapeutic consequences (eg anti-gestagens) in a large proportion of tumours. We may neglect the clinical relevance of the oestradiol receptor because it occurs in low concentrations only. The epidemiological and clinical data on patients with meningiomas, as well as the existence of sex hormone receptors, may contribute to the development of a theory on the pathogenesis of this tumour.

Adult↗

Transsphenoidal surgery for Cushing's disease.

A series of 101 patients with Cushing's disease underwent transsphenoidal surgery. Diagnosis was fundamentally based on dynamic testing, mainly on the dosage-dependent suppression of cortisol after dexamethasone. The effect of surgery was monitored by intraoperative ACTH measurements. In 96 out of 101 patients a microadenoma of the pituitary was identified and removed selectively. In 74% of patients there was a clinical and endocrinological remission of Cushing's disease. Four 'operative failures' after selective adenomectomy underwent hypophysectomy in a second operation and each remitted. Thus the overall remission rate was 77%. In general, bilateral adrenalectomy was performed in patients who had failed to remit after selective adenomectomy. Although there is a considerable mortality and morbidity in patients with Cushing's syndrome, complications attributed to surgery were low. Two patients died postoperatively. In general, an improvement of disturbed pituitary function was noted after selective adenomectomy.

Adenoma↗

Neurosurgical treatment of Cushing's disease in children and adolescents.

The authors report on 15 unselected consecutive children and adolescents treated for hypothalamo-pituitary Cushing's disease by transsphenoidal sella exploration and microadenomectomy. The diagnosis was established by dynamic endocrine testing. Peri- and post-operative measurements of ACTH levels were used to monitor the effectivity of the surgical procedure. In one patient no microadenoma was found. Hypercortisolism was corrected in 13 of the 15 patients. Although transient secondary adrenocortical insufficiency occurred in all of the successfully operated patients, no permanent damage of the anterior or posterior pituitary was found by postoperative endocrinological follow-up testing. One patient died of pneumonia as a direct consequence of surgery.

Adenoma↗

Surgical therapy of lesions within the hypothalamic region.

On one hand pituitary microadenomas with autonomous character and those, which had been influenced by hypothalamic disorders, are summarized and discussed. On the other hand, the neurosurgical management of tumours, adjacent to or involved with the hypothalamus, are described. Endocrinologically active pituitary adenomas are characterized by their hormone excess of ACTH, GH, and prolactin. In Cushing's disease endocrine and clinical remission occurred in 74%. 3 patients out of this group showed a reincrease of ACTH after a period of remission, indicating a possible hypothalamic influence. In acromegaly the hypothalamic influence is also discussed. One patient with an ectopic GRF-producing tumour showing a reincrease of GH levels after successful transsphenoidal adenomectomy has been described. In microprolactinomas, 7 patients out of 45 showed a reincrease of prolactin-levels after a period of normalization, we also discussed hypothalamic disorders. Tumours with suprasellar extension such as macroadenomas without endocrine activity and meningiomas are removed nowadays with minimal risk for the life of the patients. In craniopharyngiomas radical excision is accompanied by a high risk of hypothalamic defects caused by mechanical lesions and possible secondary vasospasm. Finally the excision of a hamartoma growing from the floor of the third ventricle into the interpeduncular cistern is discussed. Up to now the successful excision could be documented by endocrinological data, which give no sign of further growth of the hamartoma.

Acromegaly↗

Nuclear magnetic resonance imaging of the region of the sella turcica.

Nuclear magnetic resonance (NMR) imaging is a versatile technique which has proved more sensitive in the detection of perisellar lesions than CT. A multiplanar facility, the demonstration of blood flow, and the lack of bone artefacts are its main advantages in this respect. Limitations are seen in its inability to identify small calcifications and to distinguish clearly perifocal oedema and tumour especially in malignant lesions. Relatively thick slices of 5-10 mm make the detection of microadenomas very difficult, mainly because of partial volume effects. T1 and T2 values alone are not sufficient to provide specific diagnosis. No reliable criteria have been determined yet, which would indicate the quality of pathological involvement of peritumorous structures by tumours of the sella region. At present NMR still plays a more complementary role to CT in the evaluation of this complex anatomical area. We are confident that with future technical refinements NMR will be able to replace ionizing radiation for the diagnostic imaging of the sella.

Adenoma↗

Present status of neurosurgery in the treatment of prolactinomas.

Our experience with prolactinomas started in 1972 and is based on about 370 patients. Of these 247 were treated surgically, about 110 underwent medical therapy and a small number of patients were observed only. In microprolactinomas prolactin-levels could be normalized in up to 80% of the patients after selective adenomectomy. However, true recurrences were observed in 16% of the patients during long-term follow-up. The operative risk is rather low. There was no mortality in this series. The rate of complications is about 1%. Medical treatment with dopamine-agonists is successful especially in women who desire pregnancy, but should only be used in small microadenomas, in order to avoid complications. In larger macroprolactinomas h extra-sellar extension in whom primary surgical removal leads to a normalization of prolactin-levels in a minority of cases only primary therapy with dopamine-agonists leads to shrinkage of the tumour mass in about two-thirds of the patients. Since the tumour mass does not disappear completely after short-term medical treatment, we favour additional surgical tumour removal instead of long-lasting administration of dopamine-agonistic drugs in higher dosages.

Adrenergic alpha-Agonists↗

Repeatedly reversible alteration of acoustic-evoked brainstem responses with a cystic craniopharyngioma.

The case of a cystic craniopharyngioma in a young patient, in which the tumor extended in the parasellar and retrosellar region down to the left cerebellopontine angle, is described. The postoperative reversibility of alterations in the acoustic-evoked brainstem responses after repeated surgical intervention and refilling of the cyst is described. The correlations between clinical and CT findings and the repeated alterations in the evoked responses are presented. The evoked responses were instrumental in following the postoperative course and timing CT controls. It is stressed that alterations in evoked responses were used as a reliable indication to evacuate cyst fluid via a Rickham-reservoir, although hearing was still intact, thus keeping the number of repeated CT scans lower.

Adolescent↗

Ovine corticotrophin releasing factor stimulates ACTH release from human corticotrophinoma cells in culture; interaction with hydrocortisone and arginine vasopressin.

We have investigated the effects of ovine corticotrophin releasing factor (oCRF) and its interaction with hydrocortisone (HC), and arginine vasopressin (AVP) on ACTH release from human corticotrophinoma cells in culture. Tumour tissue was obtained from six patients (three with active Cushing's disease and three with Nelson's syndrome). Cultures were maintained for periods of up to six months. Ovine CRF (21 nmol) significantly (P less than 0.01) stimulated ACTH release from all tumours. Dose response (21 pmol-21 nmol) effects were observed for the three tumours investigated over 2 and 4 h. Cortisol (20 mumol) significantly (P less than 0.01) inhibited basal ACTH release from one tumour (Nelson's syndrome) by 75% over 4 h, and completely prevented the stimulatory effects of oCRF. AVP directly stimulated ACTH release from two tumours (Nelson's syndrome), and also potentiated the stimulatory action of oCRF during 30 min incubations. These data show corticotrophinoma cells from subjects with Cushing's disease and Nelson's syndrome can be directly stimulated by hypothalamic oCRF and may be potentiated by AVP. Cortisol and oCRF have been shown in one tumour to have antagonistic actions at the pituitary level.

Adrenocorticotropic Hormone↗

Cyclic Cushing's syndrome combined with cortisol suppressible, dexamethasone non-suppressible ACTH secretion: a new variant of Cushing's syndrome.

A 55 year old woman with an unusual form of Cushing's disease was studied. During several periods (periods lasting up to 84 days) evidence of cortisol hypersecretion with cycles occurring every 6 days was found. Suppression of plasma cortisol through orally administered dexamethasone (up to 32 mg per day) could not be achieved either during periods of cyclic cortisol hypersecretion or during apparent remission with normal cortisol secretion. Marked suppression of plasma ACTH was measured in response to an iv infusion of 50 mg cortisol over a period of 55 min whereas a similar test with 2 mg dexamethasone (iv bolus) did not suppress ACTH secretion. Transsphenoidal exploration of the sella revealed a tumour surrounding the anterior pituitary. Examination of the pituitary showed a few tiny tumour structures embedded in normal tissue which could not be removed, when the tumour was resected selectively under preservation of normal appearing tissue. Post-operatively, clinical and chemical remission (normal response to 1 mg dexamethasone) was observed for about 4 months. Thereafter, cortisol hypersecretion occurred again necessitating bilateral adrenalectomy. Our results are compatible with the assumption that normal hypothalamic-pituitary-adrenal suppressibility with cortisol, but not with dexamethasone, was caused by the loss of feedback receptors for dexamethasone in the presence of cortisol receptors in the cells which secrete ACTH or CRF. The combination of cyclic hypercortisolism with dexamethasone non-suppressible Cushing's syndrome has not been reported before and thus represents a new variant of Cushing's syndrome.

Adrenocorticotropic Hormone↗