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Biomedical subjects

D L Barrow

Publications and source records attributed to D L Barrow.

At least 55 records · Page 3Linked to original sources
PubMed1988

Unruptured cerebral arteriovenous malformations presenting with intracranial hypertension.

Two cases of unruptured pial arteriovenous malformations (AVMs) presenting with intracranial hypertension and papilledema are reported. In the absence of previous hemorrhage or associated hydrocephalus, such a manifestation of pial AVMs is quite unusual. Both patients experienced prompt and sustained resolution of papilledema after surgical removal of the malformation. One case was complicated by the normal perfusion pressure breakthrough phenomenon postoperatively. The pathophysiology of intracranial hypertension associated with unruptured pial AVMs and the relationship to pseudotumor cerebri are discussed.

Adult↗
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↗
PubMed1985

Preliminary report on the use of fetal tissue transplantation to correct MPTP-induced Parkinson-like syndrome in primates.

A Parkinson-like syndrome was produced in nonhuman primates and successfully reversed through transplantation of heterologous fetal mesencephalic brain tissue. Rigidity and bradykinesia were induced by the chronic administration of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Once the deficits were fixed, Macaca mulatta with well-developed Parkinson-like behavior received fetal mesencephalic cell preparations stereotactically implanted into multiple sites of the head of the caudate bilaterally. Both animals demonstrated a normalization of CSF L-dopa and significant improvement in observed activity. The neuropathological studies performed 2 months following transplantation demonstrated successful integration of fetal cells in the caudate.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
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

Classification and treatment of spontaneous carotid-cavernous sinus fistulas.

An anatomical-angiographic classification for carotid-cavernous sinus fistulas is introduced and a series of 14 patients with spontaneous carotid-cavernous sinus fistulas is reviewed to illustrate the usefulness of such a classification for patient evaluation and treatment. Fistulas are divided into four types: Type A are direct high-flow shunts between the internal carotid artery and the cavernous sinus; Type B are dural shunts between meningeal branches of the internal carotid artery and the cavernous sinus; Type C are dural shunts between meningeal branches of the external carotid artery and the cavernous sinus; and Type D are dural shunts between meningeal branches of both the internal and external carotid arteries and the cavernous sinus. The anatomy, clinical manifestations, angiographic evaluation, indications for therapy, and therapeutic options for spontaneous carotid-cavernous sinus fistulas are discussed.

Aged↗
PubMed1984

Clinical and pathological effects of bromocriptine on prolactin-secreting and other pituitary tumors.

Bromocriptine inhibits prolactin secretion and causes size reduction of prolactin-secreting adenomas. The effect of the drug upon pituitary tumors other than prolactinomas is uncertain. The authors report a prospective series of 12 patients with pituitary macroadenomas in whom bromocriptine was administered for 6 weeks prior to transsphenoidal surgery. Five of the patients had computerized tomographic documentation of significant reductions in tumor size (Group A) and six had no change (Group B) during 3 and 6 weeks of bromocriptine administration. One patient who demonstrated size reduction in his tumor was not assigned to either group as he was treated with high-dose dexamethasone concurrently with the bromocriptine. Pathological examination (light and electron microscopy and immunocytochemistry) indicated that all Group A patients harbored tumors with prolactin granules whereas all Group B tumors lacked such granules. Adenoma cells in the responsive tumors were involuted with reduced cytoplasmic, nuclear, and nucleolar areas. Neither widespread cell necrosis, infarction, nor vascular injury was observed. Two of the five Group A patients discontinued bromocriptine prior to completion of the 6-week protocol and had a rapid return of their tumors to pre-treatment size. Although bromocriptine has been reported to cause shrinkage of nonfunctional tumors, there was no radiological evidence of size reduction or pathological changes in the nonfunctional tumors of this series. Interestingly, serum levels of prolactin were modestly elevated (84 and 113 ng/ml) in two of the six Group B patients, an elevation due to stalk compression rather than secretion by adenoma cells. This finding underscores the fact that failure of bromocriptine to reduce pituitary tumor size in the presence of hyperprolactinemia may occur because the tumor is other than a prolactinoma. This is the first moderate-sized group of patients in whom pathological changes in responsive prolactinomas during bromocriptine therapy have been demonstrated. As bromocriptine is not tumoricidal, and thus not curative, there is insufficient evidence to recommend this drug as primary therapy for either prolactin-secreting or nonfunctional macroadenomas, but the drug may have potential as a preoperative adjunct to effect shrinkage of prolactinomas and theoretically, at least, make excision easier and possibly more complete.

Adenoma↗
PubMed1984

The use of greater omentum vascularized free flaps for neurosurgical disorders requiring reconstruction.

The heterotopic transfer of composite tissue, with microvascular anastomosis of an arterial supply and venous drainage to locally existing vessels, has received considerable attention in the plastic surgical literature. The use of latissimus dorsi musculocutaneous free flaps has been reported in the repair of large defects of the scalp, cranium, and dura following resection of invasive neoplasms or trauma. When the defect involves primarily subcutaneous tissue loss resulting in abnormal contour, omental free flaps provide effective coverage and restoration of contour. In addition, the inherent capability of the omentum to combat infection and form an ideal bed for the establishment of skin or bone grafts provides further indications for its use. The authors have used omental free flaps in nine cases to reconstruct gunshot wounds of the head, orbit, and face, heal chronic cavitating frontal sinus infections, form a base over exposed dura for reconstruction of the skull with rib grafts, and cover large defects after resection of invasive tumors or infected scalp. These wounds of neurosurgical interest were reconstructed with acceptable structural and aesthetic results. The indications, surgical techniques, results, alternative procedures, and potential complications of this procedure are discussed. The authors believe that omental free flaps should be considered an option in the armamentarium of reconstructive approaches for skull, dural, scalp, orbital, and facial wounds.

Adult↗
PubMed1984

Cushing's disease associated with an intrasellar gangliocytoma producing corticotrophin-releasing factor.

A 58-year-old woman had Cushing's disease with elevated plasma adrenocorticotrophin and an intrasellar tumor. Light microscopy showed that the tumor was a gangliocytoma containing immunoreactive corticotrophin-releasing factor accompanied by pituitary corticotroph hyperplasia. Ultrastructural examination identified an intimate association and desmosomal attachments between interdigitating cell processes of neurons and corticotrophs. It is suggested that Cushing's disease was due to the effect of corticotrophin-releasing factor on corticotrophs; this case represents a syndrome supporting the concept that, in some patients, Cushing's disease may have a hypothalamic origin.

Corticotropin-Releasing Hormone↗
PubMed1983

Clinical indications for computer-assisted myelography.

Computer-assisted myelography (CAM) is a technique in which computed tomography (CT) is combined with the intrathecal administration of metrizamide to demonstrate the spinal cord and surrounding structures. This retrospective study of 139 CAMs performed at Emory University Hospital included 125 CAMs that were preceded by routine metrizamide myelography (secondary CAM). The remaining 14 CAMs were primary studies without concomitant myelography. These CAMs and conventional myelograms were reviewed to provide indications for the use of CAM as a replacement for other radiodiagnostic studies or as an adjunct to radiological diagnosis. Eighty-one CAMs (58%) were positive for some pathological process. Of the 69 secondary CAMs demonstrating a pathological condition, 46 (67%) revealed some aspect of the lesion not apparent on routine metrizamide myelography. In no case with positive myelography was CAM negative. However, conventional myelography often added valuable diagnostic information. Although high resolution CT has allowed limited visualization of the spinal cord, CAM is often indicated for cases in which diagnosis requires more definition of cervicomedullary, extradural, intradural, extramedullary, and intramedullary lesions. Our clinical review found CAM to be extremely useful in the diagnostic evaluation of pathological conditions involving the spine and spinal cord and suggests clinical indications for the use of CAM based upon selected illustrative cases. Furthermore, CAM seemed to be superior to other radiological procedures in certain instances, such as in cases of spinal dysraphism and in the evaluation of lesions at the foramen magnum. Until more experience is obtained using spinal CT and CAM, CAM should not replace myelography altogether. The present study indicates that, rather than replacing conventional CT and myelography, CAM should be used as a primary study in situations where it has been shown to be superior and as a complementary study when other neurodiagnostic examinations are equivocal or nondiagnostic.

Adult↗
PubMed1983

Use of free latissimus dorsi musculocutaneous flaps in various neurosurgical disorders.

Musculocutaneous (skin-muscle) flaps have been used predominantly by plastic surgeons for a variety of reconstructive purposes. With the advent of microvascular techniques, the area to be reconstructed is no longer limited to the arc of rotation of the vascular pedicle of the muscle. Instead, the muscle and overlying skin that is best suited for the reconstructive procedure may be dissected out as a free flap, with microvascular anastomosis of an arterial supply and venous drainage to locally existing vessels. This report demonstrates the usefulness of musculocutaneous free flaps in the repair of large defects of the scalp, cranium, and dura after trauma or resection of invasive neoplasms. The authors describe the use of a latissimus dorsi free musculocutaneous flap in eight patients who would have required multiple operations to provide coverage by other techniques. There have been no major complications, and adequate repair has been accomplished, even in cases involving exposed brain.

Adult↗
PubMed1982

Serial dependencies and Markov properties of neuronal interspike intervals from rat cerebellum.

Using three different approaches, each with different theoretical assumptions, we showed that mammalian neuronal spike trains contain serial ordering. We demonstrated that: (1) when intervals are categorized according to whether their durations are short, medium, or long, sequential groupings of adjacent interval categories exhibit Markov dependencies, extending to at least the 4th order; (2) the observed incidence of specified patterns of these groups of adjacent interval categories differs from the independent case, based on Chi square goodness-of-fit tests, and by using similar procedures; (3) there is divergence from independence when adjacent interval patterns are described in terms of relative lengths of adjacent intervals. The statistical indicators of serial dependence were significantly greater when applied to the original data than when applied to the same data after shuffling. Each of these approaches leads to the notion that "information" is carried in clusters of adjacent intervals ("bytes" or "words") and moreover, we can identify which specific patterns of interspike intervals contribute most to the statistical significance (i.e., those clusters that are potential candidates for "information carriers"). In most of the ten neurons, the "memory" of the system appears to be at least 36--45 msecs.

Action Potentials↗