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Biomedical subjects

E S Flamm

Publications and source records attributed to E S Flamm.

At least 37 records · Page 2Linked to original sources
PubMed1996

Functional activation during an auditory comprehension task in patients with temporal lobe lesions.

Functional magnetic resonance imaging (fMRI) was used to map regional brain activation during an auditory comprehension task in two normal controls and two patients with left temporal lobe lesions. Activity in the superior temporal and angular gyrus regions was detected in all normal subjects. In the patients, the spatial distribution of activation ipsilateral to the lesions differed from the pattern observed in contralateral cortex or in control subjects. These studies highlight the potential of fMRI for mapping abnormal functional anatomy in the human brain.

Adult↗
PubMed1996

Transfection of human lactotroph adenoma cells with an adenovirus vector expressing tyrosine hydroxylase decreases prolactin release.

Pituitary adenomas are common intracranial neoplasms, for which surgery and radiation are usually not curative. In attempting to develop gene therapy as a better approach to treating pituitary adenomas, we chose lactotroph adenomas as a model. The rationale for the use of this model is based on the observation that dopamine agonists decrease prolactin secretion by lactotroph adenomas, and also decrease their size. We transfected primary cultures of human lactotroph adenoma cells with an adenovirus vector containing a cDNA which encodes a human tyrosine hydroxylase, the rate-limiting enzyme in the biosynthesis of dopamine. Transfection induced expression of tyrosine hydroxylase and increased production of dopamine, resulting in the predicted biologic effect of decreased prolactin secretion. These results demonstrate the potential for gene therapy of lactotroph adenomas and perhaps other pituitary adenomas, which are less amenable to pharmacologic treatment than lactotroph adenomas.

Adenoma↗
PubMed1996

Intraoperative endovascular surgery for cerebral aneurysms.

The application of a number of procedures that can be considered intraoperative endovascular neurosurgery has enhanced our ability to treat cerebral aneurysms from the abluminal surface. This study identifies a role for these techniques in the management of difficult aneurysms. A review of the last 1202 aneurysms undergoing direct clipping by the authors disclosed that these methods were used in 62 cases. Of these aneurysms, 36 arose from the internal carotid artery, 12 from the middle cerebral artery, eight from the vertebrobasilar distribution, and six from the anterior cerebral artery. The indications for applying these methods were large size (12-60 mm), intraluminal thrombus, broad neck, plaque at the neck, the potential compromise of branches at the base of the aneurysm, or a combination of these problems. The most frequently chosen intraoperative technique was suction decompression with direct removal of plaque and thrombus using suction, dissection, and/or ultrasonic aspiration. The application of temporary clips was required in all cases in which the aneurysm was opened before definitive clipping. No special pharmacological cerebral protective regimen was used. In one case in which a greater occlusion time was anticipated, cardiopulmonary bypass with profound hypothermia was performed. A favorable outcome was achieved in 73% of these difficult cases. An increased neurological deficit after surgery was seen in 11%, and the mortality rate was 8%. These methods should be considered and can be anticipated before surgery for unusual aneurysms. Many cases now being considered for embolization may be more suitable for definitive surgical obliteration.

Adult↗
PubMed1996

Functional magnetic resonance imaging of regional brain activity in patients with intracerebral arteriovenous malformations before surgical or endovascular therapy.

Functional magnetic resonance (MR) imaging was performed in six patients harboring proven intracerebral arteriovenous malformations (AVMs) using a noninvasive blood oxygen level-dependent technique based on the documented discrepancy between regional increases in blood flow and oxygen utilization in response to regional brain activation. Statistical functional MR maps were generated and overlaid directly onto conventional MR images obtained at the same session. In the six patients studied, a total of 23 separate functional MR imaging activation studies were performed. Of these, two runs were discarded because of motion artifacts. All of the remaining 21 studies demonstrated activation in or near expected regions for the paradigm employed. Qualitatively reproducible regional localizations of functional activity in unexpected sites were also seen. The authors' findings indicating aberrant mapping of cortical function may be explained on the basis of the plasticity of brain function, in that the developing brain can take over function that would normally have been performed by regions of brain encompassed by the lesion. Preliminary results in this study's small number of cases also indicate that activity demonstrated within the confines of the apparent AVM nidus may help predict the development of a posttherapy deficit. The authors demonstrate that functional MR imaging can be successfully and reproducibly performed in patients with intracerebral AVMs. Notwithstanding the paucity of normative data using functional MR imaging, the author' findings support cortical reorganization associated with these congenital lesions. Blood oxygen level-dependent MR imaging is a noninvasive method used to localize areas of eloquent cortex in patients harboring AVMs; it may prove to be of value in treatment planning.

Adolescent↗
PubMed1995

Cavernous malformations of the third ventricle.

CAVERNOUS MALFORMATIONS ARE uncommon lesions that are usually present in the cerebral hemispheres. Less frequently, these malformations are seen in the brain stem, basal ganglia, or paraventricular regions. We report four cases of cavernous malformations of the third ventricle. Patients presented with symptoms of hydrocephalus, memory loss, and signs of hypothalamic dysfunction. Magnetic resonance imaging and computed tomography provided characteristic images of the three lesions preoperatively. All patients underwent direct surgical excision of the malformations. Two patients had a transcallosal, transventricular approach, the third underwent a transcortical, transventricular approach, and the fourth had an infratentorial supracerebellar approach. Postoperatively, the patient with hypothalamic dysfunction has not improved and underwent ventriculoperitoneal shunting. The second patient did well initially; however, 8 days postoperatively, she became comatose and later died. The presumed cause of her deterioration was a hypothalamic venous infarction. The third and fourth patients have returned to their normal neurological baseline. The presenting signs and symptoms, magnetic resonance imaging and computed tomography findings, and treatment options for this rare lesion are discussed and illustrated.

Adult↗
PubMed1995

Deep central arteriovenous malformations of the brain: the role of endovascular treatment.

Cerebral deep central arteriovenous malformations (AVMs) are uncommon lesions associated with considerable difficulty in treatment. The authors report a series of 14 deep central AVMs treated by endovascular methods and examine the present role of endovascular treatment. This treatment used alone resulted in complete obliteration of AVMs in approximately 15% of case and reduction in 50% to a size permitting treatment by means of radiosurgery. Reversal of previous neurological signs and symptoms occurred in 35.7% of embolized patients. Overall, nearly 80% of patients had either complete obliteration of the lesion, reduction to a size allowing radiosurgical treatment, or reversal of previous neurological deficits. There were treatment complications in 14.3% of the cases. Endovascular treatment methods may make a significant contribution to the therapy of AVMs that have a particularly poor course and are difficult to treat by other means.

Adult↗
PubMed1995

Elective surgery for asymptomatic, unruptured, intracranial aneurysms: a cost-effectiveness analysis.

Cost-effectiveness analysis uses both economic and clinical outcomes data to evaluate treatment options. In this era of economic constraints on health care, treatments that are not cost-effective will increasingly be denied public and private insurance reimbursement. The authors used mathematical modeling techniques to assess the cost-effectiveness of elective surgery for the treatment of asymptomatic, unruptured, intracranial aneurysms. Input values for the Markov model used in this study were determined from both the literature and clinical judgment. Direct medical costs for hospitalization and physician fees were derived from Medicare cost reports and resource-based relative-value units, expressed in 1992 U.S. dollars. Costs and benefits were discounted at an annual rate of 5%. Using baseline model assumptions for a 50-year-old patient, elective aneurysm surgery provides an average of 0.88 additional quality-adjusted life years (QALYs) compared with nonsurgical treatment. However, prompt elective surgery ($23,300) costs more than expectant management ($2100), in which only patients whose aneurysms rupture incur treatment costs. Combining the outcomes and cost data, the incremental cost-effectiveness of elective aneurysm surgery is $24,200 per QALY, which is comparable to other accepted medical or surgical interventions, such as total knee arthroplasty ($15,200/QALY) or antihypertensive therapy in a 50-year-old patient ($29,800/QALY). Prompt elective surgery for asymptomatic, unruptured, intracranial aneurysms is recommended as a cost-effective use of medical resources provided: 1) surgical morbidity and mortality remain at reported levels; 2) the patient has a life expectancy of at least 13 additional years; and 3) the patient experiences a decrease in quality of life from knowingly living with an unruptured aneurysm.

Adult↗
PubMed1994

Intracranial aneurysms: depiction on MR angiograms with a multifeature-extraction, ray-tracing postprocessing algorithm.

PURPOSE: To compare a new method for postprocessing data, soft thresholding and depth cueing of unrestricted techniques (STANDOUT), with maximum intensity projection (MIP) for magnetic resonance (MR) angiograms of intracranial aneurysms. MATERIALS AND METHODS: Eighteen patients with 19 intracranial aneurysms were studied. Images generated with STANDOUT were compared with those of MIP for both three-dimensional (3D) time-of-flight (TOF) and 3D phase-contrast (PC) techniques. Images were assessed for detection of aneurysms, scored for delineation of aneurysmal features and overall MR angiographic characteristics, and compared with catheter angiograms. RESULTS: Both postprocessing techniques demonstrated aneurysms on most TOF and PC MR angiograms. Statistically significant improvement of aneurysmal features, aneurysmal neck definition, and delineation of adjacent arterial anatomy was seen on both TOF and PC MR angiograms with STANDOUT. Feature definition was most improved for smaller aneurysms. TOF and PC MR angiograms with STANDOUT showed improved elimination of artifactual intraluminal signal loss in normal large vessels, reduced artifactual narrowing of vessel caliber, and better small vessel delineation. CONCLUSION: STANDOUT has great benefits for postprocessing of intracranial MR angiograms, regardless of the technique of data acquisition.

Cerebral Arteries↗
PubMed1994

New observations on the Dandy-Cushing controversy.

It is generally known that the relationship between the two preeminent American neurosurgeons, Harvey Cushing and Walter Dandy, was strained and far from amicable. Their differences began when both men were at Johns Hopkins and continued when Cushing moved to Boston and Dandy remained in Baltimore.

History, 20th Century↗
PubMed1994

Craniopharyngiomas: a clinicopathological analysis of factors predictive of recurrence and functional outcome.

Pathological and clinical data from 56 patients operated on for craniopharyngioma since 1981 were analyzed to determine the utility of dividing patients with this tumor into distinct clinical groups based on recognized pathological type and to determine the prognostic import of brain invasion. Of the tumors in the 30 adult patients, 66% were adamantinomatous, 28% were squamous papillary, and the remainder were mixed. However, of the tumors in the 26 children, 96% were adamantinomatous and none were pure squamous papillary (P < 0.01). Forty-six percent of the children compared with 17% of the adults had brain invasion (P < 0.01). Brain invasion was present in 37% of the adamantinomatous but in only 13% of the squamous papillary tumors. Seventy-seven percent of the children underwent gross total resection (GTR) compared with 27% of the adults (P < 0.01). Sixty-three percent of the squamous papillary tumors underwent GTR compared with 54% of the adamantinomatous and mixed tumors. Follow-up ranged from 7 to 187 months (mean, 49 mo). After subtotal resection, with or without radiation therapy, 58% of the tumors recurred compared with 17% recurrence after GTR (P < 0.01), with a mean time to recurrence of 34 months. In both tumor histological types, subtotal resection was associated with a higher rate of tumor recurrence compared with gross total resection. Among the subtotally resected craniopharyngiomas, 2 of the 3 (67%) squamous papillary and 11 of the 21 (52%) adamantinomatous and mixed tumors recurred. In contrast, among the totally resected tumors, none of the 5 squamous papillary and only 5 of the 25 (20%) adamantinomatous and mixed tumors recurred. There were no significant differences in Karnofsky performance status score, mortality rate, or visual and endocrine outcomes when comparing patients based on histological tumor type. When controlling for age and extent of resection, we found that brain invasion had no significant effect on recurrence rate in totally resected tumors. Based on the limited number of patients in this series, we conclude as follows. 1) Contrary to previous reports, squamous papillary craniopharyngiomas, like adamantinomatous tumors, may recur when subtotally resected. 2) For both tumor variants, the most significant factor associated with craniopharyngioma recurrence is the extent of surgical resection rather than histopathological subtype. 3) Contrary to prior hypotheses, brain invasion in totally resected tumors does not predict higher recurrence. 4) GTR is associated with a significantly lower recurrence rate and can be achieved without sacrificing functional outcome.

Adolescent↗
PubMed1994

Morbidity and mortality from elective surgery for asymptomatic, unruptured, intracranial aneurysms: a meta-analysis.

A meta-analysis of the literature on morbidity and mortality from elective surgery for asymptomatic unruptured intracranial aneurysms was performed to obtain a more precise, accurate, and generalizable estimate of operative risk than is currently available. The authors used a MEDLINE search from 1966 to 1992, supplemented with manual searches, to locate studies containing four or more patients who had undergone elective surgery for these aneurysms. Only patients with asymptomatic, unruptured aneurysms were eligible for inclusion. Demographic and clinical data were collected from each series; aneurysms were categorized as incidental, multiple, or unclassifiable. Data were analyzed using Fisher's exact test and logistical regression. There were twenty-eight articles containing data on 733 patients who met eligibility criteria. The mean patient age was 48.6 +/- 5.5 years, and 55% +/- 17% of the patients were women. There was a total of 30 deficits for a morbidity rate of 4.1% (95% confidence interval 2.8, 5.8%) and a total of seven deaths for a mortality rate of 1.0% (95% confidence interval 0.4, 2.0%). There was insufficient statistical power to detect a difference in morbidity or mortality rates related to study size, year of publication, or potential risk factors such as patient sex or age, or aneurysm size, location, or category (incidental, multiple, or unclassifiable) (for all analyses, p > or = 0.16). Elective surgery for asymptomatic unruptured intracranial aneurysms, as reported in the literature, has low rates of morbidity (4.1%) and mortality (1.0%). At present there is insufficient detail in the literature to understand the impact of patient and aneurysm characteristics on elective surgical outcomes.

Confidence Intervals↗
PubMed1994

Neuro-intensive care of the pregnant woman.

Pregnancy may exacerbate underlying neurologic illness or may precipitate an acute neurologic emergency such as pituitary apoplexy. Care is directed to both mother and fetus in a manner designed to optimize the physiologic stability of both. A "team approach" is often needed.

Critical Care↗
PubMed1993

Role of transcranial Doppler in neuroradiological treatment of intracranial vasospasm.

BACKGROUND AND PURPOSE: The expanded role of interventional neuroradiological treatment for post-subarachnoid hemorrhage vasospasm has highlighted the diagnostic utility of transcranial Doppler studies in this condition. The role of transcranial Doppler in follow-up and determining the need for repeat intervention has not been previously emphasized. SUMMARY OF REPORT: Intracranial angioplasty for clinically evident vasospasm after subarachnoid hemorrhage was performed in four patients. In two patients, transcranial Doppler flow velocities remained elevated despite initial anatomic correction of the vasospasm. Reangiography revealed new areas of involvement by vasospasm. Reangioplasty or papaverine infusion treatment of the new lesions resulted in decreased flow velocities and clinical improvement in all patients. CONCLUSIONS: Transcranial Doppler has a more significant role than has been previously emphasized in the management of patients undergoing interventional neuroradiological treatment for intracranial vasospasm. Specifically, the persistence of elevated transcranial Doppler flow velocities after intracranial angioplasty suggests the need for repeat angiographic evaluation and possibly further therapy.

Aged↗
PubMed1993

Ocular tilt reaction resulting from vestibuloacoustic nerve surgery.

The ocular tilt reaction (OTR) is a triad of head-eye synkinesis composed of head tilt, conjugate ocular torsion in the direction of head tilt, and skew deviation. The OTR represents a normal compensatory response to lateral head tilts and is produced by activation of the utricle of the lowermost ear. A pathological OTR results when otolith activity is unopposed as the result of injury to the opposite utricle or its nerve. Vertical diplopia may be the only symptom of OTR in patients who have undergone surgery involving the vestibuloacoustic nerve. We report a series of patients with OTR after surgery for acoustic neuroma or Meniere's disease. In each patient, the manifesting symptom was vertical diplopia. Bedside neuro-ophthalmological testing readily excluded a brain stem cause for the double vision. We conclude that OTR after vestibuloacoustic surgery is a benign condition with spontaneous resolution of symptoms within several months.

Auditory Pathways↗
PubMed1993

Supraclinoid internal carotid artery fenestration with an associated aneurysm. Case report.

The case of an aneurysm occurring at the site of fenestration of the supraclinoid portion of the left internal carotid artery (ICA) is reported. A 37-year-old woman presenting with subarachnoid hemorrhage was found to have bilateral ICA aneurysms at the level of the posterior communicating arteries (PCoA's). The patient underwent right-sided craniotomy with uneventful clipping of the right PCoA aneurysm, and attempted clip placement on the contralateral left ICA aneurysm. The follow-up angiogram revealed a residual dome on the left ICA aneurysm, which was noted to originate at the proximal end of a fenestration of the left supraclinoid ICA. This represents the third reported case of fenestration of the intracranial ICA associated with an aneurysm. Intracranial artery fenestrations and their embryological origins are also reviewed.

Adult↗