PubMed Health⌕ Search

Biomedical subjects

K D Post

Publications and source records attributed to K D Post.

At least 19 recordsLinked to original sources
PubMed1995

Differential diagnosis in cushing syndrome. Use of corticotropin-releasing hormone.

Testing with ovine corticotropin-releasing hormone (CRH) has facilitated the differential diagnosis of Cushing syndrome, which is often not straightforward. We provide our experience between January 1989 and August 1993 with 30 patients with Cushing syndrome and describe 4 cases in detail to illustrate how CRH testing can be successfully applied to some of the difficulties encountered in the evaluation. CRH testing proved to be particularly useful in distinguishing cases of Cushing syndrome of adrenal etiology from those of Cushing disease with low or undetectable adrenocorticotropin (ACTH) levels. CRH testing during petrosal sinus sampling was also found to help distinguish the ectopic ACTH syndrome from pituitary-dependent Cushing syndrome. Our cases illustrate the need for careful biochemical evaluation before proceeding to imaging studies. Using CRH testing to evaluate cases of Cushing syndrome in which standard testing was inconclusive can provide useful information and lead to a more rapid determination of etiology and definitive therapy than previously possible.

ACTH Syndrome, Ectopic↗
PubMed1995

Symptomatic cavernous malformations affecting the spine and spinal cord.

Ten cases of symptomatic cavernous malformations affecting the spine and spinal cord were retrospectively reviewed. The cases display a spectrum of pathological findings involving the vertebral body, vertebral body with epidural extension, epidural space without bony involvement, intradural extramedullary space, and intramedullary lesions. Lesions at all locations are identical histologically, electron microscopically, and immunohistochemically. This perspective, in which cavernous malformations are envisioned as a single entity arising at numerous locations, runs contrary to the view found in the neurosurgical literature. In most discussions of cavernous malformations, vertebral body lesions are depicted as separate entities from intradural lesions. Cavernous malformations, also called cavernous hemangiomas, are developmental vascular hamartomas that, by definition, do not grow by mitotic activity. Yet, the expansion of these lesions is well documented both in the literature and among our cases. The therapeutic modalities used in our series included observation, embolization, radiation, and surgical resection alone or in combination. All modalities are effective but must be tailored to the specific needs and condition of the patient. The embryology, methods of treatment, and proposed mechanisms of growth, plus similarities and differences between cavernous malformations at each location, are reviewed. Analogies between spinal and intracranial lesions are presented. On the basis of this series and a review of the literature, we conclude that cavernous malformations represent a single entity regardless of location. Segregation based on location, as is prevalent throughout the neurosurgical literature, hinders an overall understanding of these lesions. Cavernous malformations are more appropriately viewed as a single pathological entity arising in a multitude of locations. The difficulties encountered when managing cavernous malformations at various locations are unique to the location and not the lesion.

Adult↗
PubMed1995

Hearing preservation in vestibular schwannoma surgery: what factors influence outcome?

The goals in the management of patients with vestibular schwannomas have changed drastically over the past few decades, with preservation of useful hearing representing the newest challenge. The true incidence of preserved useful hearing, however, has become clouded by a lack of uniformity in reporting results. The authors have analyzed 56 consecutive cases, in which directed attempts were made to preserve hearing on the involved side, to understand what factors play a major role in postoperative hearing preservation. Of the 56 cases reviewed, there were 46 patients who had "good" preoperative hearing (pure tone average < 50 dB; speech discrimination score > 50%). We found that, in this group of patients, if the tumor was less than 2 cm in diameter from pons to petrous, there was a 52% (16 of 31 patients) chance of preserving good hearing and if the tumor was 1 cm or less, the chances increased to 83%. Factors such as preoperative hearing status, tumor size and location, tumor consistency, and preoperative and intraoperative brainstem auditory evoked potentials are discussed in detail as they relate to postoperative outcome.

Adult↗
PubMed1994

Loss of heterozygosity at the retinoblastoma locus in human pituitary tumors.

BACKGROUND: Recent studies using knockouts of the Retinoblastoma (Rb) gene by homologous recombination in transgenic mice have revealed that a high frequency of heterozygous animals develop pituitary tumors associated with loss of heterozygosity (LOH) at the Rb locus. The authors have determined the frequency of LOH at the Rb locus in 42 benign human pituitary tumors. METHODS: Polymerase chain reaction- (PCR) amplification of polymorphic regions in introns 17 and 20 of the human Rb gene was used to detect heterozygosity in pituitary tumor DNA and matched control DNA samples. RESULTS: The PCR assay was informative in 42 of 48 pituitary tumors examined, and no allelic deletion of Rb was detected in any of the tumors. CONCLUSIONS: These studies confirmed a recent report that LOH at the Rb locus is rare in benign human pituitary tumors.

Base Sequence↗
PubMed1994

Craniofacial resection. An analysis of 73 cases.

OBJECTIVE: To determine the morbidity and mortality associated with a large series of patients undergoing craniofacial resection at one institution. The series is also analyzed with respect to pathology, disease recurrence, and role of adjuvant therapy. DESIGN: Retrospective review with a mean follow-up of 3 years (range, 6 months to 8 years). SETTING: Tertiary care, urban referral center. PATIENTS: The study included 73 consecutive patients (39 male and 34 female). Ages ranged from 13 to 78 years with a mean of 53.1 years. All patients had benign or malignant tumors of the paranasal sinuses. MAIN OUTCOME MEASURES: Morbidity associated with craniofacial resection was categorized as follows: early (within 30 days of surgery) or late (> 30 days); neurologic, ocular, or infectious. RESULTS: Overall morbidity rate was 63%, and the mortality rate was 2.7%. Of the patients who had complications develop, 26 had development of major morbidities and there were two mortalities. The most common complications were transient alteration in mental status (15 patients), diplopia (11 patients), cerebrospinal fluid leak (10 patients), and osteomyelitis of the frontal bone flap (eight patients). CONCLUSIONS: Craniofacial resection is an effective surgical treatment for paranasal sinus tumors. The mortality rate is acceptable and morbidity appears directly related to experience with the procedure. Infectious complications were the most devastating.

Adolescent↗
PubMed1994

Complications of cervical disk surgery.

The common complications of cervical disk surgery using the posterior and the anterior approach are discussed. The advantages and disadvantages of diskectomy with and without fusion are also presented. Complications of cervical disk surgery are a function of the type of procedure, the specific anatomic approach, and the experience of the surgeon. Although the posterior approach may be used for posterolateral or lateral herniated disks and foramenal osteophytes, the anterior approach is safer for central herniated disks and osteophyte formation. At The Mount Sinai Hospital, anterior-approach cervical diskectomy, whether with or without fusion, is preferred to the posterior approach for all herniations.

Cervical Vertebrae↗
PubMed1990

Comparison of long term results between prolactin secreting adenomas and ACTH secreting adenomas.

A series of 100 prolactin secreting pituitary adenomas was reviewed and demonstrated an early cure rate of 85.2% with a cure rate of 89% if prolactin was less than 200 ng/ml. For macroadenomas the cure rate was 50% giving an overall cure rate of 71% for the entire group. When long term (greater than 5 years) followup was obtained a 17% incidence of recurrence was noted for the microadenoma group with a 20% recurrence rate for the macroadenoma group. Secretory dynamic studies were done shortly after surgery and then after a delay. Many showed a return to normal prolactin secretory dynamic suggesting that the underlying hypothalamic regulation is normal in most patients. Abnormal secretory dynamics at 6 weeks post operative testing were not predictive of which patients would relapse as many patients who had abnormal dynamics early did not relapse even during prolonged followup. Conversely a normal response to provocative testing did not preclude late relapse. A similar series of 40 consecutive patients with Cushing's disease was reviewed. Tumor was found in all but three cases. 84% of patients were cured and thus far only one patient (2.5%) has shown late recurrence with this occurring at 6 2/3 years following surgery with normal stimulatory dynamics present for five years. The implication is that hypothalamic regulation is normal in Cushing's disease as well. The differences in recurrence rates may be reflective of the aggressiveness with which one disease is treated, with the acceptance of a higher incidence of hypopituitarism as a consequence of more radical surgery for Cushing's disease.

Adenoma↗
PubMed1990

Pituitary hemorrhage into a Rathke's cleft cyst.

This report describes a case of symptomatic pituitary hemorrhage into a Rathke's cleft cyst in a 25-year-old woman. The literature on pituitary hemorrhage in nonadenomatous sellar tumors is reviewed.

Adult↗
PubMed1990

Intramedullary ependymoma of the spinal cord.

A consecutive series of 23 patients underwent operative removal of an intramedullary spinal cord ependymoma between January, 1976, and September, 1988. Thirteen women and 10 men between the age of 19 and 70 years experienced symptoms for a mean of 34 months preceding initial diagnosis. Eight patients had undergone treatment prior to tumor recurrence and referral. Mild neurological deficits were present in 22 patients on initial examination. The location of the tumors was predominantly cervical or cervicothoracic. Radiological evaluation revealed a wide spinal cord in all cases. Magnetic resonance (MR) imaging was the single most important radiological procedure. At operation, a complete removal was achieved in all patients. No patient received postoperative radiation therapy. Histological examination revealed a benign ependymoma in all cases. The follow-up period ranged from 6 to 159 months (mean 62 months) with seven patients followed for a minimum of 10 years after surgery. Fourteen patients underwent postoperative MR imaging at intervals ranging from 8 months to 10 years postoperatively. No patient has been lost to follow-up review and there were no deaths. No patient showed definite clinical or radiological evidence of tumor recurrence during the follow-up period. Recent neurological evaluation revealed functional improvement from initial preoperative clinical status in eight patients, no significant change in 12 patients, and deterioration in three patients. The data support the belief that long-term disease-free control of intramedullary spinal ependymomas with acceptable morbidity may be achieved utilizing microsurgical removal alone.

Adult↗
PubMed1990

Intradural extramedullary tumors in adults.

Meningioma, nerve sheath tumors, and filum terminale ependymoma account for over 90% of primary intradural extramedullary tumors in adults. The demographics, radiological evaluation, and surgical techniques employed for their removal are reviewed in this article. The authors' approach to intraspinal tumors with extraspinal extension is discussed.

Adult↗
PubMed1990

Clinical versus subclinical pituitary apoplexy: presentation, surgical management, and outcome in 21 patients.

A retrospective review of 16 consecutive patients with pituitary apoplexy treated over a 10-year period is reported. Eight men and 8 women (mean age, 48 years) underwent transsphenoidal decompression after an average duration of symptoms of 19 days. The diagnosis of pituitary apoplexy was made by the sudden onset of headache (88%), nausea (56%), or meningismus (13%), with or without visual disturbances (75%), in the setting of a sellar tumor on computed tomographic or magnetic resonance imaging scans. Thirteen of 16 patients showed significant improvement of symptoms after surgery (average follow-up, 2.5 years). In addition, 5 patients with clinically silent yet extensive pituitary hemorrhage were treated. Although extensive pituitary hemorrhage often produced fulminant apoplexy, it also presented insidiously over many days with few, if any, clinical signs. Rapid diagnosis, endocrine replacement, and transsphenoidal decompression constituted effective therapy. Magnetic resonance imaging (after at least 12 hours of symptoms) was superior to computed tomography in detecting hemorrhage.

Adenoma↗
PubMed1989

Craniofacial resection of ossifying fibromas and osteomas of the sinuses.

Massive fibro-osseous lesions of the frontal and ethmoidal sinuses are rare. If left untreated, these lesions can produce chronic infection, orbital complications, and/or intracranial events. In the past, resection of these lesions has usually been subtotal and a risk of damage to intracranial structures existed, particularly to the dura, due to poor exposure, and a high recurrence rate was also present. We have treated eight such lesions with a combined craniofacial approach for total resection with resolution of symptoms, without recurrence, and without occurrence of cerebrospinal fluid leak, damage to the orbital contents or intracranial structures, or resultant cosmetic deformity.

Adolescent↗
PubMed1989

Lymphocytic hypophysitis. Report of 3 new cases and review of the literature.

Lymphocytic hypophysitis is an uncommon but increasingly recognized disorder characterized by chronic inflammation and destruction of the anterior pituitary. Three new cases are presented here with a review of the 27 previously reported cases. The disease affects primarily young women in late pregnancy or in the postpartum period but also has been described in postmenopausal women and in one man. It presents as an expanding intrasellar mass or as partial or panhypopituitarism. The etiology may be autoimmune. The natural history of this entity begins with enlargement of the pituitary secondary to inflammatory infiltration and progresses to atrophy of the gland with destruction of pituitary tissue and replacement with fibrosis. At least 1 patient had documented recovery of pituitary function, and the overall potential incidence of recoverable function is unknown. Our improved understanding of this disease has led us to conclude that surgical intervention is not always necessary.

Adolescent↗
PubMed1989

Metastatic carcinoma to the pituitary gland.

Four patients with metastatic carcinoma to the pituitary gland are presented. Two of these patients had no previous history of malignancy and, based on clinical, laboratory, and radiological evaluation, a preoperative diagnosis of pituitary adenoma was made. In one patient, the histological diagnosis of two consecutive tumour specimens, obtained 1 year apart, was pituitary adenoma. The correct diagnosis of metastatic renal-cell carcinoma was not ascertained until autopsy. In the second patient, a diffusely infiltrating breast carcinoma was diagnosed by mammography and confirmed by biopsy, after pathological examination of the sellar tumour revealed carcinoma. The third patient underwent mastectomy 3 years earlier for breast carcinoma and had known metastatic disease. The fourth patient had known metastatic endometrial carcinoma when she became symptomatic from a pituitary metastasis. The incidence, clinical features, and pathophysiology of metastatic carcinoma to the pituitary gland are discussed.

Adult↗
PubMed1988

Atlantoaxial subluxation in psoriatic arthropathy.

Symptomatic atlantoaxial dislocation occurs rarely in psoriatic arthropathy and has previously been reported only as a late complication in this disorder. We report severe upward axial dislocation and acquired basilar impression as a presenting manifestation of psoriatic arthropathy. Magnetic resonance imaging is useful in evaluating this condition.

Adult↗
PubMed1988

Metastatic carcinoma to pituitary adenoma. Report of two cases.

The authors present two patients with symptomatic carcinomas which have metastasized to pituitary adenomas. Despite the advanced age of these patients, the preoperative clinical and radiologic evaluations were consistent with pituitary adenoma. There was no previous history of malignancy in either patient, and the symptomatic pituitary metastases were responsible for the initial presentations. A review of the literature is presented with emphasis on the incidence and possible factors responsible for tumors metastasizing to distant neoplasms.

Adenoma↗
PubMed1988

Cavernous malformations of the spinal cord.

Six patients with intramedullary cavernous malformations of the spinal cord are presented. Four men and two women presented with acute, subacute, or episodic signs and symptoms of spinal cord dysfunction, ranging in duration from 3 days to 25 years. All patients underwent operative resection of the malformation. Complete removal was achieved in five patients. Neurological function either stabilized or improved postoperatively in all patients; follow-up ranged from 4 to 84 months. The increasing awareness of the propensity for recurrent hemorrhage, clinical features, and resectability of these malformations are discussed.

Adolescent↗