Adenomas no funcionantes: análisis retrospectivo de 202 pacientes / Non-functional adenomas: retrospective analysis of 202 patients

RESUMEN Los pacientes con adenomas hipofisarios constituyen una población heterogénea y requieren un enfoque individualizado. El objetivo de nuestro trabajo fue analizar nuestra población con adenomas hipofisarios no funcionantes (ACNF) y evaluar factores pronóstico de crecimiento (como el Ki-67) que ayuden en la toma de decisiones. Se realizó un análisis retrospectivo de 202 pacientes, incluyendo evaluación basal, enfoque terapéutico y evolución tumoral en 2 grupos: pacientes con conducta expectante (n = 69) y pacientes con cirugía (n = 133). La serie tuvo 55% de pacientes mujeres y la edad media al diagnóstico fue de 49 años. Los motivos de consulta más frecuentes fueron incidentaloma hipofisario y alteraciones visuales. Radiológicamente, 83% fueron macroadenomas, 77% invasivos y 55% mostraron compromiso visual. Entre los adenomas invasores, el 53% tenían disfunción hipofisaria, siendo el hipogonadismo el hallazgo más frecuente. El tratamiento inicial fue la cirugía en el 65,8% realizándose por vía transnasal en el 79% de los casos. Las complicaciones más frecuentes fueron diabetes insípida transitoria e hiponatremia, con mayor incidencia de diabetes insípida permanente en la cirugía transcraneal. La inmunohistoquímica mostró gonatropinomas en el 43,4% de los casos y fue negativa en el 37,7%. Doce adenomas tuvieron índice de proliferación Ki-67 ≥3%. Luego de la cirugía 56,8% de los pacientes mejoraron el campo visual, 22,6% recuperó alguna función endocrina y 18,8% agregó un nuevo déficit. En pacientes no operados, se observó crecimiento tumoral en 5,6% de los adenomas Hardy 1-2 y en el 21% de los Hardy 3-4. Entre los adenomas operados, aquellos sin resto tumoral postoperatorio no presentaron recurrencia. De los tumores con remanente postoperatorio (78,6%) no irradiados, el 41,5% mostró recrecimiento lesional al seguimiento. Este porcentaje se eleva a 66,6% en aquellos con Ki-67 ≥3% y disminuye a 12% en los que recibieron radioterapia.

ABSTRACT Patients with pituitary adenomas are a heterogeneous population and require an individualized approach. The aim of our study was to analyze our population of patients with nonfunctioning pituitary adenomas (NFA) and to evaluate prognostic growth factors (such as Ki-67) that help in decision making. A retrospective analysis of 202 patients, including baseline assessment, therapeutic approach and tumor evolution was performed in 2 groups: expectant management (n = 69) and surgery (n = 133). The mean age at diagnosis was 49 years, 55% women. The most frequent reasons for consultation were pituitary incidentaloma and visual impairment. Eighty three percent were macroadenomas, 77% invasive, and 55% with visual impairment. Among the invasive adenomas, 53% had pituitary dysfunction, with hypogonadism being the most frequent finding. The initial treatment was surgery in 65.8%, 79% of them through transnasal approach. The most frequent complications were transient diabetes insipidus and hyponatremia, with a higher incidence of permanent diabetes insipidus in transcranial surgery. The immunohistochemistry showed: 43.4% gonadotropinomas, 37.7% negative. Twelve adenomas had proliferation index Ki-67 ≥3%. After surgery, 56.8% improved the visual fields, 22.6% recovered some endocrine function and 18.8% added a new deficit. In non-operated patients, tumor growth was observed in 5.6% of the Hardy 1-2 adenomas and 21% of the Hardy 3-4 adenomas. Among the operated adenomas, those without postoperative tumor residue did not present recurrence. In tumors with non-irradiated postoperative remnant (78.6%), 41.5% increased. This percentage rises to 66.6% in those with Ki-67 ≥3%, and decreases to 12% in those who received radiotherapy.

Periacetabular osteotomy in patients with Down's syndrome.

We treated eight dysplastic acetabula in six skeletally mature patients with Down's syndrome by a modified Bernese periacetabular osteotomy. The mean age at the time of surgery was 16.5 years (12.8 to 28.5). Mean length of follow-up was five years (2 to 10.4).Pre-operatively the mean (Tonnis) acetabular angle was 28 degrees, the centre-edge angle was -9 degrees, and the extrusion index was 60%; post-operatively they were 3 degrees, 37 degrees, and 17%, respectively. Two patients with post-operative (Tonnis) acetabular angles > 10 degrees developed subluxation post-operatively and required secondary varus derotation femoral osteotomies. Another patient developed a late labral tear which was treated arthroscopically. All eight hips remain clinically stable, and are either asymptomatic or symptomatically improved. These results suggest that the modified Bernese periacetabular osteotomy can be used successfully in the treatment of acetabular dysplasia in patients with Down's syndrome.

Effect of treatment on quality of life among men with clinically localized prostate cancer.

BACKGROUND: Quality-of-life outcomes are an important consideration for patients evaluating therapeutic options for localized prostate cancer. OBJECTIVES: The objective of this study was to describe the effect of treatment choice on change in health-related quality of life (HRQOL) among men with clinically localized prostate cancer. RESEARCH DESIGN: This was a prospective observational study. SUBJECTS: The study subjects were 122 men with clinically localized adenocarcinoma of the prostate. Forty-two subjects (34%) underwent radical prostatectomy, 51 (42%) underwent radiation therapy, and 29 (24%) were followed with expectant management. MEASURES: The University of California at Los Angeles Prostate Cancer Quality of Life Inde- and the Medical Outcomes Study Short Form-36 were administered before and 3 and 12 months after initial treatment. The study used an analysis of covariance model adjusted for baseline differences in clinical and demographic factors. RESULTS: Men who underwent radical prostatectomy experienced significant declines in urinary and sexual function and bother that persisted at 12 months after treatment. Men treated with radiation therapy experienced smaller but significant declines in sexual function and a decline in social function. Expectant management patients did not have a significant change in disease-targeted or generic HRQOL domains. Differential rates of change in urinary and sexual function between treatment groups persisted after adjustment for differences in pretreatment clinical and demographic factors. CONCLUSIONS: Men undergoing radical prostatectomy have substantial declines in urinary and sexual function, and men undergoing radiotherapy have declines in sexual function. Men undergoing expectant management have no change in disease-specific or general HRQOL in the first year after treatment.

Randomised clinical trial of two bypass operations for unresectable cancer of the pancreatic head.

OBJECTIVE: To compare two different types of prophylactic gastric bypass in patients with cancer of the pancreatic head who were not suitable for curative resection. DESIGN: Prospective study. SETTING: University hospital, Turkey. SUBJECTS: 44 patients with unresectable cancer of the pancreatic head without duodenal obstruction who presented between May 1995 and June 2000 who were randomised into 2 groups. INTERVENTIONS: 22 patients had an antecolic, isoperistaltic gastrojejunostomy, jejunojejunostomy, and hepaticojejunostomy after cholecystectomy. The remaining 22 had a hepaticojejunostomy and antecolic, antiperistaltic gastrojejunostomy procedure after cholecystectomy. MAIN OUTCOME MEASURES: Mortality, morbidity, postoperative course, and survival. RESULTS: There were no significant differences between the groups in the incidence of postoperative complications, time until restoration of oral diet, relaparotomy rate, late upper gastrointestinal bleeding, mortality, duration of hospital stay, and survival. The isoperistaltic operation took significantly longer than the antiperistaltic operation (p < 0.001) and there was less delayed gastric emptying in the antiperistaltic group but not significantly so. Both operations caused a significant lengthening in the postoperative gastric emptying time (p = 0.04 and p = 0.01, respectively). CONCLUSION: Both procedures are suitable for patients with unresectable carcinoma of the pancreatic head without impending duodenal obstruction. There was a trend towards better clinical results with the isoperistaltic procedure.

Palliative decompression of obstructive hilar malignancies utilizing an extrahilar biliary approach.

Hilar cancers carry a dismal prognosis. Palliation of obstructive jaundice in patients with hilar cancer can be achieved by either surgical or nonsurgical means. Selection of the appropriate palliative measures is a challenging problem. Segmental bilioenteric anastomosis procedures were performed on 19 patients with hilar cancer. Seventeen of the bypasses were done to the segment III duct, known as the ligamentum teres approach, and two bypasses were to the segment V duct. Five patients, who had already been stented percutaneously or endoscopically, were operated on after the stents were clogged and a duodenal obstruction ensued. There were two postoperative deaths (10.5%) and four postoperative complications (21%). All of the 17 surviving patients experienced improvement in the level of jaundice postoperatively and the levels of serum total and direct bilirubin decreased by 78.9% and 84.2%, respectively. Two patients developed late cholangitis before death and were treated by external biliary drainage; one developed duodenal obstruction and was treated by gastrointestinal anastomosis. The mean length of hospital stay was 15.2 days. Mean survival was 8.2 months and the mean period of well-being was 7.8 months. Median survival was 7 months and median period of well being was 7 months. Three patients are still alive at 8, 8, and 24 months. These data suggest that the ligamentum teres approach offers effective palliation for patients with unresectable hilar cancer.

Extrapituitary parasellar microadenoma in Cushing's disease.

Negative sellar exploration (despite the results of endocrine evaluation indicating Cushing's disease), the high incidence of failure of total hypophysectomy, and remission of Cushing's syndrome after unsuccessful hypophysectomy and sellar irradiation suggest that the etiology of refractory Cushing's disease, in some patients, lies near the sella but not in the pituitary gland. We present 5 patients, out of 626 who received surgery for Cushing's disease, in whom an ACTH-secreting extrapituitary parasellar adenoma was identified: 2 after unsuccessful total hypophysectomy for the treatment of refractory Cushing's disease, 2 after unsuccessful hemihypophysectomy (the first, 2 yr before treatment at the NIH for Nelson's syndrome; and the second, with recurrent Cushing's disease 5 yr after negative transsphenoidal exploration), and 1 with a preoperative diagnosis of an intraclival microadenoma, which was cured by resection of the tumor. In all cases, an extrapituitary parasellar microadenoma was confirmed unequivocally as the cause of the disease, by negative pathology of the resected pituitary gland (patients 1, 2, 3, and 5), and/or the remission of the disease after selective resection of the extrasellar adenoma (patients 3, 4, and 5). Three of 5 patients had a partial empty sella. These patients support the thesis that ACTH-secreting tumors can arise exclusively from remnants of Rathke's pouch, rather than from the adenohypophysis (anterior lobe or pars tuberalis of the pituitary gland) and can be a cause of Cushing's disease. In the sixth presented case, an extrapituitary tumor was suspected at surgery after negative pituitary exploration, but serial sections of the hemihypophysectomy specimen revealed a microscopic focus of tumor at the margin of the resected gland. This case demonstrates the importance of negative pituitary histology to establish the presence of an extrapituitary parasellar tumor as an exclusive source of ACTH, and it supports the value of clinical outcome to establish the diagnosis with selective adenomectomy of an extrapituitary parasellar tumor. In patients with negative pituitary magnetic resonance imaging, especially in the presence of a partial empty sella, the diagnostic and surgical approach in Cushing's disease should consider the identification and resection of extrapituitary parasellar adenoma, which can avoid total hypophysectomy, as was possible in 3 of our 5 patients.

Two 21-kilodalton components of the Epstein-Barr virus capsid antigen complex and their relationship to ZEBRA-associated protein p21 (ZAP21).

The viral capsid antigen complex of Epstein-Barr virus (EBV), an important serodiagnostic marker of infection with the virus, consists of at least four components, with molecular masses of 150, 110, 40, and 21 kDa. Here we show that the 21-kDa component of the viral capsid antigen consists of products of two EBV genes, BFRF3 and BLRF2. Both products were expressed from late transcripts, were recognized by human antisera, and were present in virions. The BFRF3 product, but not that of BLRF2, fulfilled the definition of ZEBRA-associated protein p21 (ZAP21). In cells in which EBV was lytically replicating, BFRF3 protein was coimmunoprecipitated together with ZEBRA by a rabbit antiserum directed against amino acids 197 to 245 of BZLF1. In EBV-negative cells cotransfected with BZLF1 and BFRF3 expression vectors, BFRF3 was also coimmunoprecipitated with this antiserum. Although this antiserum could not detect BFRF3 on an immunoblot, it was able to immunoprecipitate BFRF3 in the absence of ZEBRA expression. The rabbit antiserum to amino acids 197 to 245 of BZLF1 was found to detect the same epitope at the carboxy end of BFRF3 as was recognized by rabbit antiserum to BFRF3 itself. Thus, coimmunoprecipitation of BFRF3 p21 with ZEBRA appeared to be due to cross-reactivity of the immunoprecipitating antiserum rather than to direct association of ZEBRA and BFRF3 p21.

Cushing's disease preceded by generalized glucocorticoid resistance: clinical consequences of a novel, dominant-negative glucocorticoid receptor mutation.

Generalized glucocorticoid resistance is associated with chronic hyperactivation of the hypothalamic-pituitary-adrenal axis, compensating for impaired glucocorticoid receptor function. We report a unique patient with sporadic generalized glucocorticoid resistance who, at age 33, presented with infertility and hypertension and, at 38, developed pituitary Cushing's disease. Leukocyte-binding studies revealed normal affinity of the glucocorticoid receptor but a reduction of binding sites by 50%. [3H]thymidine incorporation by this patient's lymphocytes was not suppressible by dexamethasone. He had a novel heterozygous missense mutation in the glucocorticoid receptor gene (isoleucine 559 to asparagine 559). The mutant receptor exhibited a strong dominant-negative effect on the ability of the wild-type receptor to induce gene transcription in vitro. The mutation was present in all of the patient's cultured lymphoblasts and fibroblasts as well as in 50% of his sperm, as demonstrated by single-cell polymerase chain reaction; it was not present in his parents and seven siblings. This novel mutation was thus both de novo and present in the germ line. Immunohistochemical staining of this patient's pituitary corticotropinoma revealed accumulation of p53 protein, indicating the presence of a putative somatic oncogenic mutation in the p53 gene in the tumor cells. Investigation of the lymphoblast and skin fibroblast cultures for p53 abnormalities did not show any aberration. Thus, a novel de novo germ line mutation of the glucocorticoid receptor with strong dominant-negative activity caused severe sporadic generalized glucocorticoid resistance, which preceded corticotroph adenoma formation. The latter probably was due to the combined effects of chronic corticotroph hyperstimulation, decreased glucocorticoid negative feedback, and at least one subsequent somatic defect in the control of the cell cycle.

Nelson's syndrome associated with a somatic frame shift mutation in the glucocorticoid receptor gene.

Nelson's syndrome is the appearance and/or progression of ACTH-secreting pituitary macroadenomas in patients who had previously undergone bilateral adrenalectomy for Cushing's disease. Extremely high plasma ACTH levels and aggressive neoplastic growth might be explained by the lack of appropriate glucocorticoid negative feedback due to defective glucocorticoid signal transduction. To study the glucocorticoid receptor (GR) gene in Nelson's syndrome, DNA was extracted from pituitary adenomas and leukocytes of four patients with this condition and amplified by PCR for direct sequence analysis. In one of the tumors, a heterozygous mutation, consisting of an insertion of a thymine between complementary DNA nucleotides 1188 and 1189, was found in exon 2. This frame-shift mutation led to premature termination at amino acid residue 366 of the wild-type coding sequence, excluding the expression of a functioning receptor protein from the defective allele. The mutation was not detected in the sequence of the GR gene in the patient's leukocyte DNA, indicating a somatic origin. By lowering the receptor number in tumorous cells, this defect might have caused local resistance to negative glucocorticoid feedback similar to that caused by the presence of a null allele in a kindred with the generalized glucocorticoid resistance syndrome. P53 protein accumulation, previously reported in 60% of corticotropinomas, could not be detected in any of the four pituitary tumors examined by immunohistochemistry. We suggest that a somatic GR defect might have played a pathophysiological role in the tumorigenesis of the corticotropinoma bearing this mutation.

Increased human immunodeficiency virus (HIV) type 1 DNA content and quinolinic acid concentration in brain tissues from patients with HIV encephalopathy.

Levels of human immunodeficiency virus type 1 (HIV-1) DNA and quinolinic acid were examined in areas of the central nervous system (CNS) and lymphoid organs (LN) from 5 AIDS patients with no clinically apparent CNS compromise (group I), 7 with CNS opportunistic diseases (group II), and 8 with HIV encephalopathy (group III). The brains from patients with HIV encephalopathy not only contained higher levels of HIV-1 DNA (cerebrum, P < .01; cerebellum, P < .05) as assessed by quantitative polymerase chain reaction but also showed a higher rate of viral pol region mutations suggestive of zidovudine or didanosine resistance than brains from patients in group I or II (P < .01). CNS quinolinic acid concentrations were significantly higher in group II and III patients than in group I (P = .03), even though quinolinic acid levels in LN were comparable among the 3 groups. These data suggest that CNS inflammatory changes associated with HIV encephalopathy may be triggered by a local productive HIV-1 infection within the CNS.

Fc gamma RII, Fc gamma RIII, and CD18 receptors mediate in part neutrophil activation on a plasma coated expanded polytetrafluoroethylene surface.

BACKGROUND: A biomaterial-induced polymorphonuclear neutrophil (PMN) defect may predispose the implanted vascular graft to infection. PMNs bind, activate, and undergo morphologic changes when exposed to uncoated or plasma coated expanded polytetrafluoroethylene (ePTFE) surfaces. The purpose of this study was to investigate whether the CD18 integrin receptor or the immunoglobulin receptors Fc gamma RII and Fc gamma RIII mediate either PMN binding or activation on ePTFE. METHODS: PMN binding and activation were determined after incubation of these cells on human immunoglobulin (IgG) or fibrinogen coated surfaces and uncoated or plasma coated ePTFE. PMN activation was measured by using the ferricytochrome reduction assay. Binding was determined with chromium 51-labeled PMNs. To block the Fc gamma RII, Fc gamma RIII, and CD18 receptors, PMNs were preincubated with the monoclonal antibodies (mAbs) IV.3, 3G8, and IB4, respectively. Irrelevant isotype matched mAbs were used as control. RESULTS: Monoclonal antibody IB4 inhibited binding of activated PMNs to fibrinogen coated surfaces. Binding to IgG was affected by either mAb IB4 or IV.3, but the greatest degree of inhibition was achieved when mAbs IB4 and IV.3 were used in combination. IgG-induced activation was partially inhibited by mAb IV.3 but was fully inhibited by a combination of mAbs IB4 and IV.3 The mAbs did not affect PMN binding to uncoated or plasma coated ePTFE, nor was PMN activation on the uncoated ePTFE surface inhibited. PMN activation on the plasma coated ePTFE surface was, however, partially inhibited by the combination of mAb IB4 with either mAb IV.3 or 3G8. CONCLUSIONS: A synergistic interaction between the PMN Fc gamma RII receptor and the CD18 integrin receptor accounts for surface bound IgG-induced cell activation. Both receptors also play a role in mediating PMN activation on the plasma-coated ePTFE surface.

A phase I and II trial of dose-intensified cyclophosphamide and GM-CSF in pediatric malignant brain tumors.

PURPOSE: Cyclophosphamide is commonly used in the treatment of children with malignant brain tumors. The purpose of this study was to develop a multicycle, high-dose intensity cyclophosphamide regimen with granulocyte-macrophage colony-stimulating factor (GM-CSF) and to assess its activity against malignant glioma and primitive neuroectodermal tumor (PNET). METHODS: Twenty-three patients with brain tumors, including 15 with malignant glioma and six with PNET, were enrolled. Cyclophosphamide (1.8-2.25 g/m2/day for 2 days i.v.; total dose 3.6-4.5 g/m2) was administered and was followed by recombinant human GM-CSF (5 micrograms/kg/day s.c.) on days 3-11 or until the absolute granulocyte count reached 1.5 x 10(9)/L. RESULTS: With a total of 83 cycles administered, the mean dose intensity of cyclophosphamide ranged from 1.5 g/m2/week through cycle 2 (22 patients) to 0.8 g/m2/week through cycle 8 (two patients). No activity was seen against malignant glioma, and five of six patients with PNET had partial responses. The mean duration of a neutrophil count of < 0.5 x 10(9)/L was only 8 days; the platelet recovery was substantially longer. Fever during neutropenia occurred in 54 of 83 cycles. One patient died from transfusion-related graft-versus-host disease. CONCLUSIONS: A cyclophosphamide regimen equal to twice the dose intensity of that used in conventional therapy was administered. The regimen was active against PNET but inactive against malignant glioma.

Neurosyphilis in HIV-positive and HIV-negative patients: neuroimaging findings.

PURPOSE: To evaluate and describe the neuroimaging findings of patients with neurosyphilis. METHODS: The neuroimaging studies of 35 patients with documented neurosyphilis were reviewed. Diagnosis was established in 34 patients with cerebrospinal fluid for a Venereal Disease Research Laboratory test, complemented by autopsy in 1 and brain biopsy in 1. All patients had reactive fluorescent treponemal antibody tests with absorption in their sera. Imaging studies included plain and contrast-enhanced CT of the brain, plain and gadolinium-enhanced MR, MR angiography, and conventional angiography. Imaging findings were also correlated with the relevant pathologic findings at autopsy in three additional patients with neurosyphilis who did not have brain imaging studies. RESULTS: Of the 35 patients with imaging studies, 32 tested human immunodeficiency virus (HIV)-seropositive, and 3 were HIV-seronegative. Eleven (31%) of 35 patients had normal radiographic findings. Cerebral infarctions were seen in 8 (23%) of 35 patients, and nonspecific white matter lesions in 7 (20%) of 35. Cerebral gummas and extraaxial enhancement indicating meningitis were noted in 2 (6%) of 35 patients, respectively. Arteritis was demonstrated in 2 (50%) of 4 patients who underwent either MR angiography or conventional angiography. The 3 subjects who had autopsy but not imaging studies were found to have manifestations of meningovascular syphilis, including syphilitic leptomeningitis and an obliterative endarteritis. CONCLUSION: We conclude that findings of vascular occlusive disease manifested as infarction or arteritis, enhancing cortical lesions with or without adjacent meningeal enhancement, focal or diffuse extraaxial enhancement, and white matter disease, although nonspecific, in the proper clinical setting should prompt appropriate testing for neurosyphilis, a treatable disease, in patients with and without HIV infection.

Neutrophil activation by expanded polytetrafluoroethylene is dependent on the induction of protein phosphorylation.

BACKGROUND: Polymorphonuclear leukocyte (PMN) activation after interaction with implantable surfaces has been previously reported. The purpose of this study was to examine the mechanism of PMN activation in response to expanded polytetrafluoroethylene (ePTFE). METHODS: To demonstrate PMN activation, the cumulative production of superoxide was measured on uncoated, plasma coated, or albumin coated ePTFE discs. Chromium 51-labeled PMNs were used to measure binding. Cell structure was examined by scanning electron microscopy. RESULTS: By 4 hours, PMN activation on either uncoated or plasma coated ePTFE was approximately 30% of phorbol 12-myristate 13-acetate-induced activation. Albumin inhibited PMN activation by ePTFE. No apparent correlation existed between chromium 51-labeled PMN binding and cell activation on the surfaces. Pretreatment of the cells with the protein kinase inhibitors bisindolylmaleimide or genistein resulted in marked inhibition of superoxide production on the uncoated and plasma coated ePTFE surfaces, whereas binding to these surfaces was not affected. PMNs spread on the uncoated surface and transmigrated into the plasma coated ePTFE surface. These effects of ePTFE on cell structure were inhibited by bisindolylmaleimide and genistein. CONCLUSIONS: ePTFE induced PMN activation, as measured by superoxide production, and changes in cell behavior are dependent on the activation of signaling pathways that involve protein phosphorylation events.

Clinical and pathological features of an autosomal dominant, adult-onset leukodystrophy simulating chronic progressive multiple sclerosis.

OBJECTIVE: To study the clinical and pathological features of a kindred with an adult-onset autosomal dominant leukodystrophy. PATIENTS: Five symptomatic and nine asymptomatic at-risk members of the kindred. INTERVENTIONS: Subjects underwent detailed histories and general and neurologic examinations. Further evaluation included electroencephalography, evoked potentials, electromyography, autonomic testing, and analysis of serum, urine, and cerebrospinal fluid. One patient underwent sural nerve biopsy and analysis. Another, previously studied patient, underwent a limited autopsy. RESULTS: Cerebellar and pyramidal dysfunction began in the fourth and fifth decades of life; subtle autonomic symptoms were often present years earlier. Frontal lobe dysfunction and abnormalities of the central visual pathways were mild and of late onset. Sensorineural hearing loss was common. The peripheral nervous system was spared. Autopsy results of one patient revealed severe degeneration of the white matter at all levels of the neuraxis, but most prominent in the frontoparietal and cerebellar regions, with sparing of the subcortical U fibers. Histological and ultrastructural examinations failed to show evidence of a specific pathogenetic mechanism or etiology. CONCLUSION: This disorder seems to be a distinct type of hereditary leukodystrophy, but its exact nature remains unknown.

The cost-effectiveness of early surgery versus watchful waiting in the management of small abdominal aortic aneurysms.

PURPOSE: The purpose of this study was to compare the relative cost-effectiveness of two clinical strategies for managing 4 to 5 cm diameter abdominal aortic aneurysms (AAAs): early surgery (repair 4 cm AAA when diagnosed) versus watchful waiting (monitor AAA with ultrasound size measurements every 6 months and repair if the diameter reaches 5 cm). METHODS: We used a Markov decision tree to compute the expected survival in quality-adjusted life years (QALYs) for each strategy, based on literature-derived estimates for the probabilities of different outcomes in this model. We determined hospital costs for patients undergoing elective and emergency AAA repair at our center. With standard methods of cost accounting, we then calculated the additional cost per year of life saved by early surgery compared with watchful waiting (cost-effectiveness ratio, dollars/QALY). RESULTS: Mean hospital costs for elective and emergency AAA repair were $24,020 and $43,208, respectively (1992 dollars). For our base-case analysis (60-year-old men with 4 cm diameter AAAs, with 5% elective operative mortality rate and 3.3% annual rupture rate), early surgery improved survival by 0.34 QALYs compared with watchful waiting, at an incremental cost of $17,404/QALY. Increased elective surgical mortality rate, decreased AAA rupture risk, and increased patient age all reduced the cost-effectiveness of early surgery. Future increases in elective operative risk, noncompliance with ultrasound follow-up and increased threshold size for elective AAA repair during watchful waiting all improved the cost-effectiveness of early surgery. Future increases in elective operative risk, noncompliance with ultrasound follow-up and increased threshold size for elective AAA repair during watchful waiting all improved the cost-effectiveness of early surgery. CONCLUSIONS: The cost effectiveness of early surgery for 4 cm diameter AAAs in carefully selected patients compares favorably with that of other commonly accepted preventive interventions such as hypertension screening and treatment. With an upper limit of $40,000/QALY as an "acceptable" cost-effectiveness ratio, early surgery appears to be justified for patients 70 years old or younger, if the AAA rupture risk is 3%/year or more and the elective operative mortality rate is 5% or less. Although not a substitute for clinical judgment, this cost-effectiveness analysis delineates the essential tradeoffs and uncertainties in treating patients with small AAAs.

Choreoathetosis after surgery for congenital heart disease.

Choreoathetosis developed in three patients after cardiopulmonary bypass with hypothermia. None had significant hypotension or hypoxemia; all had hypocapnia and respiratory alkalosis during the rewarming period. We postulate that hypocapnia-induced cerebral vasoconstriction may have contributed to ischemic damage in focal central nervous system areas.