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1.
Acta Otorhinolaryngol Ital ; 34(2): 123-8, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24843223

RESUMEN

Vestibular function is often underdiagnosed in vestibular schwannomas (VS). To evaluate it in a selected group of patients harbouring vestibular schwannomas, 64 patients were included in this study, recruited between March 2008 and June 2011 at our institution. All patients underwent Gd-enhanced MRI and complete neurotological evaluation before gamma knife surgery. Morphological measurements included Koos Classification and quantification of internal acoustic canal filling in length and diameter. Cochlear and vestibular functions were assessed considering pure tone and speech audiometry, bedside examination and caloric test by videonystagmography. A statistical analysis was performed to find possible correlations between morphological and cochleovestibular data. Patients with a higher intracanalicular length (ICL, mean value 8.59 and median 8.8 mm) of the tumour presented a higher value of UW than the subgroup with a lower length (51.9 ± 24.3% and 38.8 ± 18.1% respectively, p = 0.04), while no difference was detected for pure tone audiometry (PTA) values (50.9 ± 22.3 db and 51.1 ± 28.9 db respectively). Patients with a higher ICL also presented a higher rate of positive HIT (88% and 60% respectively, p = 0.006). Patients with a higher value of intracanalicular diameter (ICD, mean value 5.22 and median 5.15 mm) demonstrated higher values of UW (50.2 ± 29.1% and 39.3 ± 21% respectively, p = 0.03), but not different PTA (50.2 ± 29.1 db and 51.9 ± 29.9 db respectively). Finally, patients with a positive head impulse test (HIT) demonstrated significantly higher values of unilateral weakness (UW) (p = 0.001). Vestibular disorders are probably underdiagnosed in patients with VS. ICL and ICD seem to be the main parameters that correlate with vestibular function. Also, in case of small intracanalar T1 VS a slight increase of these variables can result in significant vestibular impairment. The data reported in the present study are not inconsistent with the possibility of proactive treatment of patients with VS.


Asunto(s)
Neuroma Acústico/fisiopatología , Pruebas de Función Vestibular , Femenino , Humanos , Masculino , Persona de Mediana Edad
2.
J Clin Neurosci ; 19(11): 1582-3, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22954791

RESUMEN

Deep brain stimulation (DBS) can be complicated by adverse events, which are generally classified as surgical-hardware or stimulation-related. Here we report the onset of a painful cervical dystonia probably triggered by the extension wire of a subthalamic nucleus (STN)-DBS device in a woman suffering from advanced Parkinson's disease (PD). Two months after implantation of the STN-DBS device, our patient developed a painful cervical dystonia, which was not responsive to neurostimulation or to medication. No sign of infections or fibrosis was detected. A patch test with the components of the device was performed, revealing no hypersensibility. The patient was referred back to surgery to reposition the pulse generator in the contralateral subclavian region. A deeper channeling of the wire extensions produced a complete remission of the painful dystonia.


Asunto(s)
Estimulación Encefálica Profunda/efectos adversos , Estimulación Encefálica Profunda/instrumentación , Electrodos Implantados/efectos adversos , Tortícolis/etiología , Anciano , Falla de Equipo , Femenino , Humanos , Dolor/etiología , Enfermedad de Parkinson/cirugía , Enfermedad de Parkinson/terapia , Reoperación , Núcleo Subtalámico/lesiones
3.
Minerva Anestesiol ; 78(6): 729-32, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21525826

RESUMEN

Prosthetic valve endocarditis (PVE) is a serious complication with potential fatal consequences, classified as early or late PVE, depending on whether typical symptoms occur within or later than 12 months from surgery. The incidence of early PVE is under 1%, but it carries high morbidity and mortality rates. There are few reported cases in literature of PVE due to Corynebacterium Jeikeium even though it is present in normal skin flora particularly in hospitalized patients. Corynebacterium species are, in fact, recognized as uncommon agents of endocarditis and little is known regarding species-specific risk factors and the outcome in this kind of endocarditis. Described is an unusual case report of a 57-year-old man who had early aortic PVE due to Corynebacterium Jeikeium infection complicated by dehiscence of the prosthesis, complete atrio-ventricular block, perforation of the interventricular septum and septic shock. Prompt diagnosis, choice of daptomycin as antibiotic therapy although it has only been approved by the European Medicine Agency (EMEA) for right-sided endocarditis and timely open heart surgery, resulted in a successful outcome.


Asunto(s)
Antibacterianos/uso terapéutico , Válvula Aórtica/cirugía , Infecciones por Corynebacterium/tratamiento farmacológico , Corynebacterium , Daptomicina/uso terapéutico , Endocarditis Bacteriana/tratamiento farmacológico , Prótesis Valvulares Cardíacas/efectos adversos , Infecciones Relacionadas con Prótesis/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad
4.
AJNR Am J Neuroradiol ; 33(5): 803-17, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22016411

RESUMEN

MR imaging is the preferred technique for the diagnosis, treatment planning, and monitoring of patients with neoplastic CNS lesions. Conventional MR imaging, with gadolinium-based contrast enhancement, is increasingly combined with advanced, functional MR imaging techniques to offer morphologic, metabolic, and physiologic information. This article provides updated recommendations to neuroradiologists, neuro-oncologists, neurosurgeons, and radiation oncologists on the practical applications of MR imaging of neoplastic CNS lesions in adults, with particular focus on gliomas, based on a review of the clinical trial evidence and personal experiences shared at a recent international meeting of experts in neuroradiology, neuro-oncology, neurosurgery, and radio-oncology.


Asunto(s)
Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/cirugía , Imagen por Resonancia Magnética/normas , Guías de Práctica Clínica como Asunto , Cirugía Asistida por Computador/normas , Adulto , Humanos , Estados Unidos
5.
J Cardiovasc Surg (Torino) ; 52(4): 613-9, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21792167

RESUMEN

AIM: The aim of this study was to analyze our experience with combined treatment of non-small cell lung cancer with synchronous brain metastases. METHODS: Between 1992 and 2008, 31 patients were treated by performing neurosurgery (or stereotactic radiosurgery) and lung surgery. Patients were divided into two groups according to their preoperative mediastinal work-up: group A (CT scan) and group B (FDG-PET scan). RESULTS: Twenty-six patients had one brain metastasis and five had two. Neurosurgery was performed in 10 patients, stereotactic radiosurgery in 20 and both approaches in 1. Seven patients underwent chemotherapy after cerebral procedure. Pulmonary resection was complete in 27 cases and incomplete in 4. Histological findings showed: adenocarcinoma in 19 cases, squamous cell carcinoma in 8 and large cell carcinoma in 4. All patients underwent adjuvant chemotherapy. Overall 1, 2 and 5-year survival rates were 83%, 47% and 21%, respectively. The median survival was 22 months. Univariate analysis showed a better prognosis for complete resection (P=0.008), adenocarcinomas (P=0.015), N0 disease (P=0.038), and Group B (P=0.045). Multivariate analysis showed that only the radicality of the resection (P=0.027) and Group B (P=0.047) were independent prognostic factors. CONCLUSION: Our experience confirms that selected patients with non-small cell lung cancer and synchronous brain metastases may be effectively treated by combined therapy. Complete resection, adenocarcinoma histology and N0 disease were prognostic factors. The incorporation of FDG-PET scan into the preoperative work-up may translate into a survival benefit.


Asunto(s)
Neoplasias Encefálicas/terapia , Carcinoma de Pulmón de Células no Pequeñas/terapia , Neoplasias Pulmonares/terapia , Procedimientos Neuroquirúrgicos , Neumonectomía , Adulto , Anciano , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/secundario , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/secundario , Quimioterapia Adyuvante , Femenino , Fluorodesoxiglucosa F18 , Humanos , Italia , Estimación de Kaplan-Meier , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos/efectos adversos , Procedimientos Neuroquirúrgicos/mortalidad , Oportunidad Relativa , Neumonectomía/efectos adversos , Neumonectomía/mortalidad , Tomografía de Emisión de Positrones , Modelos de Riesgos Proporcionales , Radiofármacos , Radioterapia Adyuvante , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Tasa de Supervivencia , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
6.
J Endocrinol Invest ; 34(8): 623-9, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21427527

RESUMEN

Surgical removal of non-functioning pituitary adenoma (NFPA) is the first-choice therapeutic option, but radical removal of the tumor cannot be accomplished in all patients. The best strategy to prevent regrowth of NFPA is still a matter of debate. Adjuvant radiotherapy is very effective in reducing recurrence rate after incomplete removal of NFPA, but concerns still exist about long-term toxicity of radiation. Different modalities have been developed to irradiate the pituitary region. One major distinction is between radiation techniques that deliver the total dose in multiple sessions using 3 fixed radiation beams and radiosurgical equipment that delivers the total dose to the target volume in a single treatment session. Progression-free survival of patients with NFPA treated by adjuvant radiotherapy is well above 90% at 5 yr in most studies and diminishes only slightly at 10 yr. Very few studies have a more prolonged follow-up. In comparison, the 5- and 10-yr estimated recurrence rate without adjuvant radiotherapy ranged from 15% to 51% and from 44% to 78%, respectively. Complications of radiation include rare but severe side-effects, such as secondary brain neoplasm, optic neuropathy, cerebrovascular accidents, and more frequent but less severe complications, such as pituitary deficiency. Optimal management of patients with residual or recurring NFPA after surgical debulking can be achieved through the judicious use of different treatment options, necessitating close cooperation between neurosurgeons, endocrinologists, and radiation oncologists.


Asunto(s)
Recurrencia Local de Neoplasia/radioterapia , Neoplasias Hipofisarias/radioterapia , Radioterapia Adyuvante/métodos , Supervivencia sin Enfermedad , Humanos , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/cirugía , Hipófisis/patología , Hipófisis/efectos de la radiación , Hipófisis/cirugía , Neoplasias Hipofisarias/patología , Neoplasias Hipofisarias/fisiopatología , Neoplasias Hipofisarias/cirugía , Radioterapia Adyuvante/instrumentación , Resultado del Tratamiento
7.
Br J Ophthalmol ; 93(1): 40-4, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18757470

RESUMEN

AIM: To present our treatment protocol and evaluate the results of Gamma knife radiosurgery (GKR) in treating patients with uveal melanoma. METHODS: Seventy-eight consecutive patients with uveal melanoma underwent stereotactic radiosurgery (radiation dose 30-50 Gy) with a Leksell Gamma-Knife at the San Raffaele University Hospital, Milan, Italy between 1994 and 2006. The main outcome measures evaluated were: survival rate, local tumour control, eye retention rate, visual acuity and treatment-related complications. RESULTS: Survival rate was 88.8% at 3 years and 81.9% at 5 years. Local tumour control was achieved in 91.0% of patients. The median tumour thickness reduction after treatment was 1.96 mm (p<0.0001) (-32.1%). The eye retention rate was 89.7%. A significant relative reduction of visual acuity was observed during follow-up. The most frequent treatment-related complications were: exudative retinopathy (33.3%), neovascular glaucoma (18.7%), radiogenic retinopathy (13.5%) and vitreous haemorrhages (10.4%). CONCLUSION: GKR can be considered an alternative to enucleation for the treatment of choroidal melanomas.


Asunto(s)
Melanoma/cirugía , Radiocirugia , Neoplasias de la Úvea/cirugía , Anciano , Medios de Contraste , Femenino , Estudios de Seguimiento , Gadolinio , Humanos , Estimación de Kaplan-Meier , Imagen por Resonancia Magnética/métodos , Masculino , Melanoma/mortalidad , Persona de Mediana Edad , Radiocirugia/mortalidad , Resultado del Tratamiento , Neoplasias de la Úvea/mortalidad , Agudeza Visual
8.
Neurology ; 66(9): 1435-8, 2006 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-16682682

RESUMEN

The authors assessed MATILDE chemotherapy followed by response-tailored radiation therapy in 41 patients aged 70 years or younger with primary CNS lymphoma in a Phase II trial. With response rates of 76% after MATILDE and 83% after chemotherapy with or without radiation therapy, this was an active strategy, particularly in low- to intermediate-risk patients (International Extranodal Lymphoma Study Group [IELSG] score). Myelosuppression was the dose-limiting toxicity, with 9.5% of lethal complications. After a median follow-up of 49 months, a plateau in the survival curve (5-year overall survival: 41 +/- 7%) was obtained.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias del Sistema Nervioso Central/tratamiento farmacológico , Irradiación Craneana , Linfoma no Hodgkin/tratamiento farmacológico , Radioterapia Adyuvante , Adolescente , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias del Sistema Nervioso Central/mortalidad , Neoplasias del Sistema Nervioso Central/radioterapia , Terapia Combinada , Irradiación Craneana/efectos adversos , Citarabina/administración & dosificación , Citarabina/efectos adversos , Femenino , Enfermedades Hematológicas/inducido químicamente , Humanos , Idarrubicina/administración & dosificación , Idarrubicina/efectos adversos , Tablas de Vida , Linfoma no Hodgkin/mortalidad , Linfoma no Hodgkin/radioterapia , Masculino , Neoplasias Meníngeas/tratamiento farmacológico , Neoplasias Meníngeas/mortalidad , Neoplasias Meníngeas/radioterapia , Metotrexato/administración & dosificación , Metotrexato/efectos adversos , Persona de Mediana Edad , Radioterapia Adyuvante/efectos adversos , Inducción de Remisión , Accidente Cerebrovascular/etiología , Análisis de Supervivencia , Tiotepa/administración & dosificación , Tiotepa/efectos adversos
9.
Chir Ital ; 53(2): 267-73, 2001.
Artículo en Italiano | MEDLINE | ID: mdl-11396079

RESUMEN

To understand the level of acceptance, awareness and usefulness of informed consent, a group of 119 patients (59 men and 60 women) from different types of hospitals were given a questionnaire which required only 'YES or NO' answers, both before and after surgery. The questionnaire concerned the patient's knowledge about pathology, operative risks, approval, anxiety caused, understanding of information received and consent given, and also if he would inform a relative in the same condition. From the analysis of the results it was established that: the more information a patient has about his illness and operation risks, the more he will want to have; the less he knows the less he will want to know, and he will also have more faith in the doctors. Some patients would not inform a relative with a similar pathology. To conclude, informed consent, instead of being a right of the patient is progressively becoming more a right of the doctor. It does not have any real effect on the patient's choice but is useful, as it represents a moment of personalised attention from medical personnel, though the patient may not completely understand the information received. There are few advantages in strictly medical terms but informed consent has increased malpractice litigation.


Asunto(s)
Consentimiento Informado , Procedimientos Quirúrgicos Operativos , Femenino , Humanos , Masculino , Estudios Prospectivos
10.
World J Surg ; 24(5): 571-3, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10787078

RESUMEN

The major complication of thyroid surgery, occurring in 1% to 6% of cases, is injury to the recurrent laryngeal nerve (RLN). A simple method to identify the RLN during thyroid surgery is described by the authors. It consists in palpation of the nerve caudally to the inferior pole of the thyroid, after the nerve has been made taut by the upward and medial traction of the thyroid gland. This method was used on 47 human cadavers and 45 patients with benign thyroid diseases. It made it possible to identify the RLN in all of the cadavers and 52 of the 55 identifications during 45 thyroidectomies (in 10 total thyroidectomies the identification was bilateral). Laryngeal motility was normal in all patients at postoperative laryngoscopy. Using the palpation before dissection in the region of the inferior thyroid artery, the traditional viewing method became easier and safer, reducing the risk of injury where it is most likely to occur to the nerve.


Asunto(s)
Cuidados Intraoperatorios/métodos , Complicaciones Intraoperatorias/prevención & control , Palpación , Nervio Laríngeo Recurrente/anatomía & histología , Tiroidectomía , Cadáver , Humanos
11.
Chir Ital ; 52(4): 379-84, 2000.
Artículo en Italiano | MEDLINE | ID: mdl-11190528

RESUMEN

We report on our experience with laparoscopic cholecystectomy in 15 patients, 12 females and 3 males (mean age: 44 years), with chronic acalculous cholecystitis. These patients presented with recurrent episodes of biliary colic together with a dysmorphic or dysfunctioning gallbladder as confirmed by ultrasound and/or cholescintiscan with 99m-Tc HIDA performed in fasting conditions and after meals. First of all, we considered the possible presence of concomitant digestive disease (peptic ulcer disease, recurrent pancreatitis, irritable bowel syndrome, chronic hepatitis) potentially responsible for the pain. Ultrasound investigations revealed a pathological gallbladder in 10 patients. Cholecystectomy was curative in 8/10. Cholescintiscan revealed a pathological gallbladder in 8 patients and cholecystectomy was curative in only 5 of these. No postoperative deaths or significant complications occurred. The mean duration of the operation (35 vs 48 min) and hospital stay (2.1 vs 2.8 days) were reduced in comparison to 346 cholecystectomies performed for gallstones. After 6-36 months' follow-up, resolution of symptoms was successful in 10/15 cases (66.6%); in 3 cases, only dyspepsia was reduced, whilst in the other 2 cases, who also presented concomitant irritable bowel syndrome and gastroduodenitis, there was no improvement in pain. In all but the latter two cases (86.6%), histological examination revealed chronic gallbladder inflammation. In conclusion, laparoscopic cholecystectomy was curative (66.6%) or led to an improvement in symptoms (20%) in patients with chronic acalculous cholcystitis. Cholescintiscans were not always diagnostic for the disease, whereas ultrasound findings were more useful as an indication for surgery.


Asunto(s)
Colecistectomía Laparoscópica , Colecistitis/diagnóstico , Colecistitis/cirugía , Adulto , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad
13.
Minerva Chir ; 47(3-4): 135-42, 1992 Feb.
Artículo en Italiano | MEDLINE | ID: mdl-1314346

RESUMEN

This paper reports a case of pancreatic VIPoma with widespread hepatic metastasis which was treated for approximately 2 years with a synthetic somatostatin analog (SMS 201/995). The treatment of choice in cases in which the tumour was fully removable is surgical resection. This occurred rarely since approximately 80% of VIPomas are malignant and are operated late when local infiltration is already widespread; in addition, 50% of cases are already metastasised at diagnosis. In this case, due to the infiltration of the superior mesenteric artery by the primary tumour it was necessary to carry out a left pancreasectomy which included two-thirds of the neoplastic mass. This was justified by slow tumour growth and also facilitated control of diarrhea and ensured a greater efficacy of possible postoperative chemotherapy. The use of synthetic somatostatin analog (SMS 201/995) enabled diarrhea to be satisfactorily controlled and is therefore specifically indicated for this type of tumour. NSE serum assay (neuron specific enolase) allowed the evolution of disease to be monitored during follow-up.


Asunto(s)
Neoplasias Pancreáticas/cirugía , Vipoma/cirugía , Femenino , Humanos , Neoplasias Hepáticas/secundario , Persona de Mediana Edad , Neoplasias Pancreáticas/enzimología , Fosfopiruvato Hidratasa/sangre , Vipoma/enzimología , Vipoma/secundario
14.
Minerva Chir ; 45(3-4): 157-62, 1990 Feb.
Artículo en Italiano | MEDLINE | ID: mdl-2162504

RESUMEN

Three Zollinger-Ellison syndrome patients were treated during the period January 1977 to June 1978. The first patient is in good health 11 years 3 months after a total gastrectomy as is the second patient, 11 year after the enucleation of a cephalo-pancreatic gastrinoma. However the third patient died from malignancy 5 years after a total gastrectomy and enucleation of a cephalo-pancreatic gastrinoma followed by therapeutic cycles with streptozotocin and 5-fluorouracil. The decline in the Zollinger-Ellison syndrome over the last ten years is examined and the type of surgical treatment is discussed. Total gastrectomy once advocated as the preferred treatment, is now reappraised because of the effectiveness of medical therapy in controlling ulcers and because of the frequent malignancy of pancreatic gastrinomas.


Asunto(s)
Síndrome de Zollinger-Ellison , Adulto , Carcinoma Hepatocelular/secundario , Femenino , Estudios de Seguimiento , Gastrinas/sangre , Humanos , Italia/epidemiología , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Síndrome de Zollinger-Ellison/sangre , Síndrome de Zollinger-Ellison/patología , Síndrome de Zollinger-Ellison/cirugía
15.
Minerva Anestesiol ; 55(3): 107-10, 1989 Mar.
Artículo en Italiano | MEDLINE | ID: mdl-2615972

RESUMEN

Results concerning 42 (38 males-2 females) cervical vertebro-medullary traumas are described in which early surgery was undertaken. 24.3% were operated within 24 hrs from trauma; 45% between 24 hrs and 7 days; 26% more than 7 days after: 69.3% during first week. Six patients died (5 of grade 1 in accordance with Sunnibrook; 1 of grade 2) within 30 days after trauma (5 during first week after surgery). These patients had more frequent systemic complications (56% respiratory and cardio-vascular insufficiency). Total mortality during one year was 22.7%. The neurological and rehabilitation observations support the opinion that early operated patients limitedly improved.


Asunto(s)
Vértebras Cervicales/lesiones , Traumatismos de la Médula Espinal/cirugía , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Estudios Retrospectivos , Traumatismos de la Médula Espinal/complicaciones , Factores de Tiempo
16.
Minerva Anestesiol ; 55(3): 119-22, 1989 Mar.
Artículo en Italiano | MEDLINE | ID: mdl-2615975

RESUMEN

Somatosensory evoked potentials have been serially recorded in 21 patients with cervical spinal cord injury. Each patient received the SEP test and a full neurological examination within 1 day after admission, after surgery, and 3-6 weeks following admission. Further SEP test and clinical evaluation were carried out 3-6 months after injury. Neurological status was graded according to the Sunnybrook Scale. In all patients we evaluated latency and amplitude of SEPs obtained from both median and tibial nerve stimulation. Immediately following injury SEPs were absent in 6 patients, abnormal in 10, and normal in 5 patients. No surgery was carried out in patients with normal SEPs where myelography and CT scan could not demonstrate surgical lesions. Four patients had some distal motor improvement but SEPs still absent, one had traceable SEPs following surgery but no motor improvement. Surgery was performed in all 10 patients with abnormal SEPs: 7 patients improved following surgery. In two patients SEPs showed an early postoperative recovery with subsequent late clinical improvement. The SEP technique is well suited to the non invasive study of spinal cord condition and serial recording in patients with spinal cord injury. Although SEPs are of limited clinical value when absent immediately following trauma, the presence of well preserved median and tibial SEP in the postinjury period indicates the best prognosis for motor and sensory functions.


Asunto(s)
Vértebras Cervicales/lesiones , Potenciales Evocados Somatosensoriales , Traumatismos de la Médula Espinal/fisiopatología , Adolescente , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad
17.
J Comput Assist Tomogr ; 11(3): 390-7, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3106433

RESUMEN

Blood-brain barrier (BBB) permeability to [68Ga]EDTA was measured by positron emission tomography (PET) in four normal volunteers and in 11 patients with brain tumors. A unidirectional transfer constant, Ki, was calculated applying multiple-time graphical analysis (MTGA). This method allows the detection of backflux from brain to blood and, by generalization, the measurement of the constant Kb (brain to blood). Furthermore, the need for an independent measurement of the intravascular tracer is obviated: MTGA itself provides an estimate of the cerebral plasma volume (Vp). In the four normal volunteers the Ki was 3.0 +/- 0.8 X 10(-4) ml g-1 min-1 (mean +/- SD) and the Vp 0.034 +/- 0.007 ml g-1. A net increase in Ki up to a maximum of 121.0 X 10(-4) ml g-1 min-1 (correspondent value of Kb = 0.025 min-1) as well as an increase of Vp was observed in malignant tumors. The input function was calculated using both the [68Ga]EDTA concentration in sequential arterial blood samples and, noninvasively, the activity derived from the superior sagittal sinus image. The values of Ki and Vp from these two calculations were in good agreement. The application of MTGA to PET permits the evaluation of passage of substances across the BBB without making assumptions about the compartments in which the tracer distributes.


Asunto(s)
Barrera Hematoencefálica , Permeabilidad Capilar , Tomografía Computarizada de Emisión/métodos , Adulto , Anciano , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/fisiopatología , Neoplasias Encefálicas/secundario , Ácido Edético , Radioisótopos de Galio , Humanos , Persona de Mediana Edad
19.
Acta Neurol Scand ; 74(4): 269-78, 1986 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-3811832

RESUMEN

The 4-vessel occlusion rat model of cerebral ischemia was modified to permit the simultaneous measurement of cerebral blood flow (hydrogen clearance), brain edema (specific gravity), cerebrovascular permeability (14C-AIB) and electrocardiogram. Surgery was performed in one stage in the anesthetised, paralysed and ventilated rat and severe hemispheric ischemia was produced in all animals. Electrode implantation did not alter cortical specific gravity or Ki for 14C-AIB. During 4-vessel occlusion mean cortical CBF was 5.8 +/- 1.4 ml-1 100 g-1 min. and this was associated with an isoelectric ECoG; 15 min of ischemia produced a significant reduction in mean cortical specific gravity (increase in brain edema). Following 15 min ischemia, 180 min of recirculation were permitted. Post-ischemic blood flow showed an immediate hyperemia (CBF = 202 +/- 12 ml-1 100 g-1 min.) followed by hypoperfusion (CBF = 58 +/- 8 ml-1 100 g-1 min). There was an early further decrease in cortical specific gravity. Further recirculation led to a significant increase in cortical specific gravity (resolution of brain edema). The transfer constant (Ki) for 14C-AIB was not altered at any stage in recirculation. This appears to be a model of pure cytotoxic edema until 180 min recirculation after 15 min cerebral ischemia. Recirculation permitted return of cortical electrical activity.


Asunto(s)
Isquemia Encefálica , Modelos Animales de Enfermedad , Animales , Barrera Hematoencefálica , Edema Encefálico/etiología , Isquemia Encefálica/complicaciones , Isquemia Encefálica/fisiopatología , Corteza Cerebral/fisiopatología , Circulación Cerebrovascular , Electroencefalografía , Masculino , Ratas , Ratas Endogámicas
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