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1.
Neurocrit Care ; 17(3): 324-33, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22311233

RESUMEN

BACKGROUND: Interhospital transfer of patients with intracranial hemorrhage can offer improved care, but may be associated with complications. METHODS: A prospective single-center study was conducted between 2/2008 and 6/2010 of patients with subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH) and subdural hemorrhage (SDH), admitted to the neuro-ICU at a tertiary-care academic hospital. Admission demographics, complications and 3-month functional outcomes were compared between directly admitted and transferred patients. The effect of transfer time on complications and outcomes was assessed. RESULTS: Of 257 total patients, 120 (47%) were transferred and 137 (53%) were directly admitted. About 86 (34%) had SAH, 80 (31%) had ICH and 91 (35%) had SDH. The median transfer time was 190 min (46-1,446). Transferred patients were significantly less educated, less likely to be insured and more frequently had SAH as a diagnosis than directly admitted patients (all P < 0.05), though admission neurological and cognitive status was similar. Complications did not differ between transferred and directly admitted patients; however, among transferred patients, longer transfer time was associated with aneurysm rebleed (7.3 vs. 1.8%, P = 0.007) and tracheostomy (20 vs. 17.5%, P = 0.013). In multivariate analysis, after adjusting for other predictors, transferred patients had worse cognitive outcome at 3-months (adjusted OR 12.4, 95% CI 1.2-125.2, P = 0.033) compared to direct admits, though there were no differences in death, disability or length of stay (LOS). CONCLUSIONS: Transferred patients had similar rates of death, disability and LOS as directly admitted patients, though worse 3-month cognitive outcomes. Prolonged time to interhospital transfer was associated with an increased risk of aneurysm rerupture and tracheostomy.


Asunto(s)
Hemorragias Intracraneales/mortalidad , Hemorragias Intracraneales/terapia , Evaluación de Resultado en la Atención de Salud/estadística & datos numéricos , Transferencia de Pacientes/estadística & datos numéricos , Centros de Atención Terciaria/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Crítica/mortalidad , Evaluación de la Discapacidad , Femenino , Hematoma Subdural/mortalidad , Hematoma Subdural/rehabilitación , Hematoma Subdural/terapia , Mortalidad Hospitalaria , Humanos , Incidencia , Unidades de Cuidados Intensivos/estadística & datos numéricos , Hemorragias Intracraneales/rehabilitación , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Hemorragia Subaracnoidea/mortalidad , Hemorragia Subaracnoidea/rehabilitación , Hemorragia Subaracnoidea/terapia , Adulto Joven
2.
Am J Physiol Heart Circ Physiol ; 281(5): H2018-27, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11668063

RESUMEN

In the present study, we report the effects of adenosine receptor antagonists on pial vasodilatation during contralateral sciatic nerve stimulation (SNS). The pial circulation was observed through a closed cranial window in alpha-chloralose-anesthetized rats. In artificial cerebrospinal fluid (CSF), SNS resulted in a 30.5 +/- 13.2% increase in pial arteriolar diameter in the hindlimb somatosensory cortex. Systemic administration of the selective adenosine A2A receptor antagonist, 4-(2-[7-amino-2-[2-furyl][3,2,4]triazolol[2,3-a][1,3,5]triazin-5-yl-amino] ethyl)phenol (ZM-241385), significantly (P < 0.05, n = 6) attenuated the SNS-induced vasodilatation. Systemic administration of 8-(p-sulfophenyl)theophylline (8SPT), a nonselective antagonist that is blood-brain barrier (BBB) impermeable, had no effect on vasodilatation to SNS. In contrast, systemic theophylline, which readily penetrates the BBB, nearly abolished the SNS-induced vasodilatation (P < 0.01; n = 7). Topical superfusion of 8SPT significantly (P < 0.01; n = 6) attenuated vasodilatation during SNS. Topical superfusion of 8- cyclopentyl-1,3-dipropylxanthine (DPCPX), a selective adenosine A1 receptor antagonist, significantly potentiated SNS-induced vasodilatation (P < 0.01; n > or = 5). Hypercarbic vasodilatation and somatosensory-evoked potentials were not affected by any of the compounds tested. Our findings suggest that luminal endothelial adenosine receptors are not involved in the arteriolar response to SNS, as demonstrated by a lack of effect with systemic 8SPT. Furthermore, the adenosine A2A receptor subtype appears to be involved in the dilator response to SNS. Finally, the neuromodulatory action of adenosine, via the A1 receptor subtype, significantly influences SNS-induced vasodilatation. Thus the present study provides further evidence for a role of adenosine in the regulation of CBF during somatosensory stimulation.


Asunto(s)
Adenina/análogos & derivados , Piamadre/irrigación sanguínea , Antagonistas de Receptores Purinérgicos P1 , Nervio Ciático/fisiología , Teofilina/análogos & derivados , Vasodilatación/fisiología , Adenina/farmacología , Administración Tópica , Animales , Estimulación Eléctrica , Inhibidores Enzimáticos/farmacología , Potenciales Evocados Somatosensoriales , Inyecciones Intraperitoneales , Masculino , Ratas , Ratas Sprague-Dawley , Teofilina/farmacología , Triazinas/farmacología , Triazoles/farmacología , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Xantinas/farmacología
3.
Neurology ; 57(6): 1100-3, 2001 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-11571343

RESUMEN

The authors abstracted the records of 43 patients treated with intra-arterial urokinase for acute ischemic stroke to identify predictors of serious complications. Sixteen (37%) had such a complication. Higher urokinase dose (>1.5 x 10(6) U), higher mean arterial blood pressure before treatment (>130 mm Hg), basilar occlusive strokes, and severe strokes were most predictive of these complications. Although urokinase is no longer manufactured, these findings identify patients at risk for complications from other intra-arterial thrombolytics.


Asunto(s)
Infarto Cerebral/tratamiento farmacológico , Terapia Trombolítica , Activador de Plasminógeno de Tipo Uroquinasa/efectos adversos , Enfermedad Aguda , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Infusiones Intraarteriales , Masculino , Persona de Mediana Edad , Garantía de la Calidad de Atención de Salud , Estudios Retrospectivos , Factores de Riesgo , Activador de Plasminógeno de Tipo Uroquinasa/uso terapéutico
5.
Am J Physiol Heart Circ Physiol ; 280(5): H2329-35, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11299238

RESUMEN

The purpose of this study was to investigate the receptor subtypes that mediate the dilation of rat intracerebral arterioles elicited by adenosine. Penetrating arterioles were isolated from the rat brain, cannulated with the use of a micropipette system, and luminally pressurized to 60 mmHg. Both adenosine and the A2A receptor-selective agonist CGS-21680 induced dose-dependent vasodilation (-logEC(50): 6.5 +/- 0.2 and 8.6 +/- 0.3, respectively). However, adenosine, which is capable of activating both A2A and A2B receptors, caused a greater maximal dilation than CGS-21680. The A2A receptor-selective antagonist ZM-241385 (0.1 microM) only partially inhibited the dilation induced by adenosine but almost completely blocked CGS-21680-induced dilation. Neither 8-cyclopentyl-1,3-dipropylxanthine (0.1 microM), an A1 receptor-selective antagonist, nor MRS-1191 (0.1 microM), an A3 receptor-selective antagonist, attenuated adenosine dose responses. Moreover, ZM-241385 had no effect on the dilation induced by ATP (10 microM) or acidic (pH 6.8) buffer. We concluded that the A2A receptor subtype mediates adenosine-induced dilation of intracerebral arterioles in the rat brain. Furthermore, our results suggest that A2B receptors may also participate in the dilation response to adenosine.


Asunto(s)
Adenosina/análogos & derivados , Circulación Cerebrovascular/fisiología , Receptores Purinérgicos P1/fisiología , Vasodilatación/fisiología , Adenosina/farmacología , Adenosina Trifosfato/farmacología , Animales , Antihipertensivos/farmacología , Arteriolas/fisiología , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Masculino , Fenetilaminas/farmacología , Quinazolinas/farmacología , Ratas , Ratas Sprague-Dawley , Triazinas/farmacología , Triazoles/farmacología , Vasodilatación/efectos de los fármacos
6.
Neurology ; 56(6): 766-72, 2001 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-11274312

RESUMEN

BACKGROUND: Withdrawal of support in patients with severe brain injury invariably leads to death. Preconceived notions about futility of care in patients with intracerebral hemorrhage (ICH) may prompt withdrawal of support, and modeling outcome in patient populations in whom withdrawal of support occurs may lead to self-fulfilling prophecies. METHODS: Subjects included consecutive patients with supratentorial ICH. Radiographic characteristics of the hemorrhage, clinical variables, and neurologic outcome were assessed. Attitudes about futility of care were examined among members of the departments of neurology and neurologic surgery through a written survey and case presentations. RESULTS: There were 87 patients with supratentorial ICH; overall mortality was 34.5% (30/87). Mortality was 66.7% (18/27) in patients with Glasgow Coma Score < or = 8 and ICH volume > 60 cm(3). Medical support was withdrawn in 76.7% (23/30) of patients who died. Inclusion of a variable to account for the withdrawal of support in a model predicting outcome negated the predictive value of all other variables. Patients undergoing surgical decompression were unlikely to have support withdrawn, and surgery was less likely to be performed in older patients (p < 0.01) and patients with left hemispheric hemorrhage (p = 0.04). Survey results suggested that practitioners tend to be overly pessimistic in prognosticating outcome based upon data available at the time of presentation. CONCLUSIONS: The most important prognostic variable in determining outcome after ICH is the level of medical support provided. Withdrawal of support in patients felt likely to have a "poor outcome" biases predictive models and leads to self-fulfilling prophecies. Our data show that individual patients in traditionally "poor outcome" categories can have a reasonable neurologic outcome when treated aggressively.


Asunto(s)
Hemorragia Cerebral/fisiopatología , Eutanasia Pasiva , Cuidados para Prolongación de la Vida , Anciano , Hemorragia Cerebral/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Tiempo
7.
Radiology ; 218(2): 598-601, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11161185

RESUMEN

By using a 1.5-T whole-body magnetic resonance (MR) imager, a high-spatial-resolution single-shot echo-planar technique was developed to perform blood oxygen level dependent functional MR imaging of rat sensory cortex during forepaw stimulation. This technique produced cubic 1-mm(3) voxels. Signal-to-noise ratio was 140-160 (43-44 dB). Optimal effective echo time was 50 msec. This system should prove useful for developing new functional MR imaging techniques with rapid adaptation to human use.


Asunto(s)
Encéfalo/patología , Imagen Eco-Planar/métodos , Imagen por Resonancia Magnética/métodos , Oxígeno/sangre , Animales , Humanos , Masculino , Ratas , Ratas Sprague-Dawley
8.
Clin Nucl Med ; 26(2): 125-30, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11201469

RESUMEN

PURPOSE: The primary objective of this study was to correlate Tc-99m HMPAO and ethyl cysteine dimer perfusion brain SPECT imaging with angiography and transcranial Doppler (TCD) to identify vasospasm after subarachnoid hemorrhage. METHODS: A retrospective analysis of consecutive patients who had cerebral blood flow SPECT imaging for subarachnoid hemorrhage and aneurysm clipping was made. Flow velocity measurements were correlated using TCD and cerebrovascular angiography. RESULTS: Of the 129 patients were included in this study, 84 were female and 45 were male, with a mean age of 51.9 years and a median age of 51 years (range, 9 to 84 years). Eighty-nine patients had brain SPECT evidence of hypoperfusion. Concordance was found between SPECT and TCD with vasospasm in 57 of 89 (64%) patients and nonconcordance was evident in 32 patients (36%). Eleven patients who had concordance between SPECT and TCD had nonconcordant results of angiography for vasospasm. CONCLUSIONS: These findings suggest that all three methods are complementary to each other in the evaluation of patients with vasospasm after subarachnoid hemorrhage. Concordance of 64% between SPECT and TCD is acceptable and explicable by the differences in technique and measurement of cerebral blood flow compared with vascular narrowing, respectively.


Asunto(s)
Encéfalo/diagnóstico por imagen , Hemorragia Subaracnoidea/complicaciones , Hemorragia Subaracnoidea/diagnóstico por imagen , Vasoespasmo Intracraneal/diagnóstico por imagen , Vasoespasmo Intracraneal/etiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Angiografía Cerebral , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiofármacos , Estudios Retrospectivos , Exametazima de Tecnecio Tc 99m , Tomografía Computarizada de Emisión de Fotón Único , Ultrasonografía Doppler Transcraneal
9.
Skull Base ; 11(3): 219-23, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17167623
10.
Neurosurgery ; 49(5): 1068-74; discussion 1074-5, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11846899

RESUMEN

INTRODUCTION: Increasing costs and concerns about blood supply safety have led to a reevaluation of blood transfusion practices. This study was undertaken to examine blood use during aneurysm surgery. METHODS: We performed a retrospective analysis of hospital records including operative, anesthetic, and nursing notes, computed tomographic scans, and four-vessel angiographic films of 547 patients undergoing surgery for ruptured and unruptured cerebral aneurysms at Harborview Medical Center in Seattle. During the review period, the transfusion threshold was not altered. RESULTS: A total of 134 patients (24.5%) received an intraoperative blood transfusion (median number of units, 2; range, 1-17). Preoperative factors associated with intraoperative blood use included older patient age (P < 0.001), lower hematocrit level on admission (P = 0.007), ruptured rather than unruptured aneurysm (P = 0.004), severe intraventricular hemorrhage (P = 0.03), and larger aneurysm size (P = 0.004). Factors not associated with intraoperative blood transfusion included past medical history (including cardiac or pulmonary disease), admission clinical grade after aneurysm rupture, findings such as hydrocephalus on computed tomographic scanning, and aneurysm location and aneurysm neck-to-fundus ratio. Also associated with blood transfusion during surgery were intraoperative aneurysm rupture (P < 0.0001), intracerebral hematoma evacuation (P = 0.02), and obliteration of multiple aneurysms (P = 0.002). Among patients who received an intraoperative transfusion, those who experienced an aneurysm rupture required an average of 3.6 +/- 0.35 units, whereas patients who did not have a rupture required 1.9 +/- 0.12 units (P = 0.001). Postoperatively, a total of 244 patients (44.6%), including 77 who received blood intraoperatively, required a blood transfusion (median number of units, 2; range, 1-31). Postoperative blood transfusion was associated with the treatment of patients with subarachnoid hemorrhage (P < 0.0001), particularly among poor-grade patients who developed medical complications. CONCLUSION: Blood transfusion can be expected in one in five patients undergoing aneurysm surgery. Reducing intraoperative rupture may reduce the need for blood products.


Asunto(s)
Aneurisma Roto/cirugía , Transfusión Sanguínea , Aneurisma Intracraneal/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Aneurisma Roto/sangre , Pérdida de Sangre Quirúrgica/fisiopatología , Pérdida de Sangre Quirúrgica/prevención & control , Niño , Preescolar , Femenino , Registros de Hospitales , Humanos , Aneurisma Intracraneal/sangre , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Hemorragia Subaracnoidea/sangre , Hemorragia Subaracnoidea/cirugía
11.
J Neurosurg ; 93(1 Suppl): 8-14, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10879752

RESUMEN

OBJECT: The use of structural allografts in spinal osteomyelitis remains controversial because of the perceived risk of persistent infection related to a devitalized graft and spinal hardware. The authors have identified 47 patients over the last 3.5 years who underwent a surgical decompression and stabilization procedure in which fresh-frozen allografts were used after aggressive removal of infected and devitalized tissue. The patients subsequently underwent 6 weeks of postoperative antibiotic therapy (12 months for those with tuberculosis [TB]). METHODS: Follow-up data included results of serial clinical examinations, radiography, laboratory analysis (erythrocyte sedimentation rate and white blood cell count), and clinical outcome questionnaires. Of the original 47 patients (14 women and 33 men, aged 14-83 years), 39 were available for follow up. The average follow-up period at the time this article was submitted was 17 +/- 9 months (median 14 months, range 6-45 months). In the majority of cases (57%), a Staphylococcus species was the infectious organism. Predisposing risk factors included intravenous drug abuse (IVDA), previous surgery, diabetes, TB, and concurrent infections. During the follow-up period only two patients suffered recurrent infection at a contiguous level; both had a history of IVDA and one also had a chronic excoriating skin condition. No other recurrent infections have been identified, and no patient has required reoperation for persistent infection or allograft/hardware failure. CONCLUSIONS: It is the authors' opinion that the use of structural allografts in combination with aggressive tissue debridement and adjuvant antibiotic therapy provide a safe and effective therapy in cases of spinal osteomyelitis requiring surgery.


Asunto(s)
Trasplante Óseo/métodos , Osteomielitis/cirugía , Enfermedades de la Columna Vertebral/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Sedimentación Sanguínea , Trasplante Óseo/diagnóstico por imagen , Descompresión Quirúrgica , Complicaciones de la Diabetes , Femenino , Estudios de Seguimiento , Humanos , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Dispositivos de Fijación Ortopédica/microbiología , Osteomielitis/diagnóstico por imagen , Radiografía , Recurrencia , Estudios Retrospectivos , Factores de Riesgo , Enfermedades de la Columna Vertebral/diagnóstico por imagen , Infecciones Estafilocócicas , Abuso de Sustancias por Vía Intravenosa/complicaciones , Procedimientos Quirúrgicos Operativos/efectos adversos , Infección de la Herida Quirúrgica/microbiología , Trasplante Homólogo , Resultado del Tratamiento , Tuberculosis Pulmonar/complicaciones
12.
Ann Pharmacother ; 34(6): 697-702, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10860128

RESUMEN

OBJECTIVE: To determine the incidence of intravenous site reactions to phenytoin and valproate in a large population of patients with neurotrauma. DESIGN: Retrospective chart review of two double-blind, randomized clinical trials evaluating the use of antiepileptic drugs to prevent posttraumatic seizures in patients with neurotrauma: phenytoin versus placebo (n = 390), and valproate versus phenytoin with placebo (n = 385). Information collected from the charts included the number, type, and location of intravenous lines and intravenous site events. SETTING: Tertiary care trauma and university teaching hospital. MAIN RESULTS: Intravenous site reactions occurred in 18% and 25% of patients receiving valproate or phenytoin, respectively, with the majority of events (70%) occurring in the first intravenous site. Patients received the neurosurgery study drug (NSSD) by either central or peripheral lines; all intravenous site reactions occurred in peripheral administration sites. When patients who received the drug by central line during the course of therapy were excluded, the estimated incidence of site reactions was 21% and 30% for valproate and phenytoin, respectively (p = 0.056). The time to the first event was shorter with phenytoin compared with valproate (2.0 +/- 1.3 vs. 3.0 +/- 1.9 d; p = 0.009). Fewer adverse events were noted with phenytoin in the phenytoin-without-valproate study than in the phenytoin-with-valproate study, with 4.3% and 8.2% of intravenous site events recorded in patients receiving placebo or phenytoin, respectively. There was no significant difference in the number of intravenous lines per patient used during NSSD drug infusion for phenytoin versus placebo or phenytoin versus valproate. CONCLUSIONS: Both intravenous phenytoin and valproate resulted in intravenous site reactions, with the loading doses responsible for the majority of the events.


Asunto(s)
Anticonvulsivantes/efectos adversos , Dolor/inducido químicamente , Fenitoína/efectos adversos , Ácido Valproico/efectos adversos , Adulto , Anciano , Anticonvulsivantes/administración & dosificación , Lesiones Encefálicas/tratamiento farmacológico , Lesiones Encefálicas/cirugía , Distribución de Chi-Cuadrado , Método Doble Ciego , Femenino , Humanos , Infusiones Intravenosas/efectos adversos , Masculino , Persona de Mediana Edad , Fenitoína/administración & dosificación , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Retrospectivos , Ácido Valproico/administración & dosificación
13.
J Neurosurg ; 92(6): 955-60, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10839255

RESUMEN

OBJECT: The aim of this study was to determine the incidence and clinical significance of complications related to preoperative embolization of cerebral arteriovenous malformations (AVMs) with silk sutures as documented on postprocedure computerized tomography (CT) scans. METHODS: The CT scans were obtained within 12 to 24 hours after 221 (96%) of 230 consecutive embolizations in 70 patients. These CT scans were evaluated for the presence of ischemia, infarction, hemorrhage, or contrast agent extravasation. Adverse patient outcomes were determined after each embolization and were correlated with CT findings. New abnormalities demonstrated on CT scans were also correlated with the Spetzler-Martin AVM grade, degree of arteriovenous shunting, and location. New abnormalities, the majority of them infarcts, resulted from 29 (13%) of 221 embolization procedures. In 11 (38%) of 29 cases of new CT findings, patients were asymptomatic, including 10 with new infarcts on CT scans. New neurological deficits occurred in 20 (8.7%) of 230 total embolization procedures in 19 patients, including one death. Permanent deficits occurred in nine patients (3.9% per embolization procedure, 12.8% per patient). Of the patients with new neurological deficits, 18 (90%) of 20 embolization procedures resulted in new abnormalities on CT scans. Two patients with new transient neurological deficits had no new findings on CT scans. Spetzler-Martin grade, AVM location, degree of arteriovenous shunting, and higher numbers of procedures were not statistically associated with a higher incidence of abnormalities on CT scans or new permanent neurological deficits. CONCLUSIONS: Silk sutures are an effective and relatively safe embolic agent. After brain AVM embolization with silk sutures, new abnormalities were found on CT scans obtained in one of eight procedures. When a new CT finding occurred, the patient had roughly equal chances of having no new symptoms, having new transient neurological deficits, or having new permanent neurological deficits.


Asunto(s)
Embolización Terapéutica , Proteínas de Insectos , Malformaciones Arteriovenosas Intracraneales/terapia , Cuidados Preoperatorios , Suturas , Adulto , Embolización Terapéutica/efectos adversos , Femenino , Humanos , Proteínas de Insectos/efectos adversos , Malformaciones Arteriovenosas Intracraneales/diagnóstico por imagen , Malformaciones Arteriovenosas Intracraneales/cirugía , Masculino , Persona de Mediana Edad , Enfermedades del Sistema Nervioso/diagnóstico por imagen , Enfermedades del Sistema Nervioso/etiología , Estudios Retrospectivos , Seda , Suturas/efectos adversos , Tomografía Computarizada por Rayos X
14.
J Trauma ; 48(3): 558-61, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10744306

RESUMEN

BACKGROUND: The National Acute Spinal Cord Injury Studies have been a series of trials assessing the role of pharmacologic agents in the prevention of secondary neuronal damage after acute spinal cord injury. METHODS: The trials were multicenter randomized, controlled studies. RESULTS: Two trials have demonstrated the efficacy of high-dose methylprednisolone in improving neurologic and functional recovery and have shown a reassuring safety profile. CONCLUSION: This study responds to a recent commentary on these trials and examines in particular the roles of clinical measurement, statistical analysis, and risk benefit in assembling evidence for or against innovative therapies.


Asunto(s)
Antiinflamatorios/uso terapéutico , Metilprednisolona/uso terapéutico , Traumatismos de la Médula Espinal/tratamiento farmacológico , Antiinflamatorios/efectos adversos , Interpretación Estadística de Datos , Relación Dosis-Respuesta a Droga , Medicina Basada en la Evidencia , Humanos , Metilprednisolona/efectos adversos , Examen Neurológico/efectos de los fármacos , Ensayos Clínicos Controlados Aleatorios como Asunto , Medición de Riesgo , Resultado del Tratamiento
15.
Am J Physiol Heart Circ Physiol ; 278(3): H878-85, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10710357

RESUMEN

K(+) dilate and constrict cerebral vessels in a dose-dependent fashion. Modest elevations of abluminal K(+) cause vasodilatation, whereas larger extracellular K(+) concentration ([K(+)](out)) changes decrease cerebral blood flow. These dilations are believed to be mediated by opening of inward-rectifier potassium channels sensitive to Ba(2+). Because BaCl(2) also blocks ATP-sensitive K(+) channels (K(ATP)), we challenged K(+) dilations in penetrating, resistance-size (<60 mmu) rat neocortical vessels with the K(ATP) channel blocker glibenclamide (1 microM). Glibenclamide reduced K(+) responses from 138 +/- 8 to 110 +/- 0.8%. K(+) constrictions were not affected by glibenclamide. The Na(+)-K(+)-pump inhibitor ouabain (200 microM) did not significantly change resting vessel diameter but decreased K(+) dilations (from 153 +/- 9 to 99 +/- 2%). BaCl(2) blocked K(+) dilations with a half-maximal dissociation constant of 2.9 microM and reduced dilations to the specific K(ATP) agonist pinacidil with equal potency. We conclude that, in resistance vessels, K(+) dilations are mediated by K(ATP); we hypothesize that [K(+)](out) causes activation of Na(+)-K(+) pumps, depletion of intracellular ATP concentration, and subsequent opening of K(ATP). This latter hypothesis is supported by the blocking effect of ouabain.


Asunto(s)
Adenosina Trifosfato/farmacología , Encéfalo/irrigación sanguínea , Neuronas/fisiología , Canales de Potasio/fisiología , Adenosina Trifosfato/metabolismo , Animales , Compuestos de Bario/farmacología , Cloruros/farmacología , Gliburida/farmacología , Hidrólisis , Cinética , Neocórtex/irrigación sanguínea , Potasio/farmacología , Bloqueadores de los Canales de Potasio , Ratas , Ratas Sprague-Dawley , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Vasodilatación/efectos de los fármacos
16.
Neurology ; 54(4): 895-902, 2000 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-10690983

RESUMEN

OBJECTIVES: To examine the neuropsychological side effects of valproate (VPA) given to prevent posttraumatic seizures. METHODS: In a randomized, double-masked, parallel group clinical trial, we compared the seizure prevention and neuropsychological effects of 1 or 6 months of VPA to 1 week of phenytoin. We studied 279 adult subjects who were randomized within 24 hours of injury and examined with a battery of neuropsychological measures at 1, 6, and 12 months after injury. We examined drug effects cross-sectionally at 1, 6, and 12 months and longitudinally by examining differential change from 1 to 6 months and from 6 to 12 months as a function of protocol-dictated changes in treatment. RESULTS: No significant adverse or beneficial neuropsychological effects of VPA were detected. CONCLUSIONS: Valproate (VPA) appears to have a benign neuropsychological side effects profile, making it a cognitively safe antiepileptic drug to use for controlling established seizures or stabilizing mood. However, based on this study, VPA should not be used for prophylaxis of posttraumatic seizures because it does not prevent posttraumatic seizures, there was a trend toward more deaths in the VPA groups, and it did not have positive effects on cognition.


Asunto(s)
Lesiones Encefálicas/tratamiento farmacológico , Lesiones Encefálicas/psicología , Ácido Valproico/uso terapéutico , Adolescente , Adulto , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Escalas de Valoración Psiquiátrica
17.
Neurosurg Focus ; 8(3): E6, 2000 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-16676929

RESUMEN

In patients with Chiari I malformation with and without associated syringomyelia, aberrant cerebrospinal fluid (CSF) dynamics and a spectrum of posterior fossa pathological findings are demonstrated. In this study, the authors test the validity of using prospective cardiac-gated phase-contrast cine-mode magnetic resonance (MR) imaging to define the malformation, delineate its pathophysiology, and assist in implementing a rational treatment plan. Eighty-five cases were prospectively analyzed using cine MR imaging. Sixty-five patients, adults and children, with symptomatic Chiari malformation, with and without syringomyelia, were surgically treated from 1990 to 1999. All patients underwent pre- and postoperative cine MR evaluation. Ten patients were treated after a previous surgical procedure had failed. To establish CSF flow characteristics and normative CSF profiles, 20 healthy volunteers were examined. Compared with normal volunteers, in Chiari I malformation patients with and without syringomyelia, uniformly abnormal craniocervical junction CSF flow profiles were revealed. After intradural exploration, nearly all patients with Chiari I malformation experienced clinical improvement and CSF flow profiles, paralleling those of normal volunteers, were shown. In all patients in whom treatment had failed, abnormal preoperative CSF flow profiles, which correlated with suspected physiological abnormalities and the pathological findings noted at reoperation, were demonstrated. Symptomatic Chiari I malformation is a dynamic process characterized by the impaction of the hindbrain in an abnormal posterior fossa. This compression obstructs the normal venting of CSF in and out of the craniocervical subarachnoid space, throughout the cardiac cycle. Therefore, decompression or enlargement of the posterior fossa to establish normal CSF pathways should be the primary goal of surgical intervention. Aberrant CSF flow appears to be only one aspect of the pathological condition found in patients with Chiari I malformation. Arachnoid scarring in the posterior fossa and selective vulnerability of the spinal cord may also be factors in the pathogenesis and maintenance of associated syringomyelia. Phase-contrast cine MR imaging is a useful tool in defining physiological and anatomical problems in patients with Chiari I and syringomyelia, and it can help guide an appropriate primary or salvage surgical therapy.


Asunto(s)
Malformación de Arnold-Chiari/patología , Malformación de Arnold-Chiari/cirugía , Siringomielia/patología , Siringomielia/cirugía , Adolescente , Adulto , Malformación de Arnold-Chiari/complicaciones , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Siringomielia/complicaciones , Resultado del Tratamiento
18.
Neurosurgery ; 45(6): 1465-7; discussion 1467-8, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10598715

RESUMEN

OBJECTIVE AND IMPORTANCE: Posterior fossa subarachnoid hemorrhage secondary to blunt head trauma is rarely associated with traumatic aneurysms of the posterior circulation. CLINICAL PRESENTATION: We present three cases of posterior fossa subarachnoid hemorrhage from ruptured posteroinferior cerebellar artery (PICA) aneurysms after blunt head trauma. In each case, there was no associated penetrating injury or cranial fracture. All three patients presented with acute hydrocephalus requiring ventriculostomy. Two of the three patients had a proximal PICA aneurysm visible on emergent angiography. The remaining patient's aneurysm, although not visible on his initial angiogram, was detected on a subsequent angiogram 72 hours later. INTERVENTION: All patients underwent successful surgical clipping of their aneurysms. Two cases required sacrificing of the parent vessels because of the friable nature of the false aneurysms. In each case, severe symptomatic vasospasm occurred, requiring angioplasty. All three patients also required a ventriculoperitoneal shunt for persistent hydrocephalus. CONCLUSION: Features of these three cases and similar cases reported in the literature support the theory that vascular ruptures and traumatic aneurysms of the proximal PICA may be related to anatomic variability of the PICA as it transverses the brainstem. This variability predisposes individuals to vascular lesions, which occur in a continuum based on the severity of the injury. Posterior fossa subarachnoid hemorrhage after head injury requires a high index of suspicion and warrants aggressive diagnostic and therapeutic interventions.


Asunto(s)
Cerebelo/irrigación sanguínea , Traumatismos Cerrados de la Cabeza/cirugía , Aneurisma Intracraneal/cirugía , Adolescente , Adulto , Arterias/lesiones , Arterias/cirugía , Angiografía Cerebral , Femenino , Traumatismos Cerrados de la Cabeza/diagnóstico , Humanos , Aneurisma Intracraneal/diagnóstico , Masculino , Hemorragia Subaracnoidea/diagnóstico , Hemorragia Subaracnoidea/cirugía , Tomografía Computarizada por Rayos X
19.
Arch Neurol ; 56(11): 1348-52, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10555654

RESUMEN

BACKGROUND: The brain is rich in creatine kinase-BB isoenzyme activity (CK-BB), which is not normally present in cerebrospinal fluid (CSF). Results of previous studies have shown that CK-BB can be detected in the CSF of patients with aneurysmal subarachnoid hemorrhage (SAH), but whether CK-BB levels correlate with patients' neurologic outcomes is unknown. OBJECTIVE: To evaluate the relationship between CSF CK-BB level and outcome after SAH. DESIGN: Prospective observational cohort. SETTING: University-affiliated tertiary care center. PATIENTS: Convenience sample of 30 patients seen for cerebral aneurysm clipping. INTERVENTIONS: We sampled and assayed CSF for CK isoenzymes a median of 3 days after SAH in 27 patients, and at the time of unruptured aneurysm clipping in 3 patients. MAIN OUTCOME MEASURES: Without knowledge of CK results, we assigned the Glasgow Outcome Scale score early (approximately 1 week) and late (approximately 2 months) after surgery. RESULTS: Higher CSF CK-BB levels were associated with higher Hunt and Hess grades at hospital admission (Spearman rank correlation, p = 0.69; P<.001), lower Glasgow Coma Scale scores at hospital admission (p = -0.72; P<.001), and worse early outcomes on the Glasgow Outcome Scale (p = -0.64; P<.001). For patients with a favorable early outcome (Glasgow Outcome Scale score, 3-5), all CK-BB levels were less than 40 U/L. With a cutoff value of 40 U/L, CK-BB had a sensitivity of 70% and a specificity of 100% for predicting unfavorable early outcome (Glasgow Outcome Scale score, 1-2). Having a CK-BB level greater than 40 U/L increased the chance of an unfavorable early outcome, from 33% (previous probability) to 100%, whereas a CK-BB level of 40 U/L or less decreased it to 13%. Similar findings were obtained when considering late outcomes. CONCLUSION: The level of CSF CK-BB may help predict neurologic outcome after SAH.


Asunto(s)
Creatina Quinasa/líquido cefalorraquídeo , Hemorragia Subaracnoidea/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Escala de Coma de Glasgow , Humanos , Aneurisma Intracraneal/complicaciones , Aneurisma Intracraneal/cirugía , Isoenzimas , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Sensibilidad y Especificidad , Hemorragia Subaracnoidea/etiología , Factores de Tiempo , Resultado del Tratamiento , Ventriculostomía/métodos
20.
Crit Care Clin ; 15(4): 685-99, v, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10569116

RESUMEN

Endovascular treatment of cerebral vasospasm induced by subarachnoid hemorrhage has become a useful therapy. The two main treatments that have been used are balloon angioplasty and intra-arterial papaverine infusion. Both treatments have been shown to reverse subarachnoid hemorrhage-induced vascular spasm, increase cerebral blood flow and improve delayed ischemic neurologic deficits induced by vasospasm. Balloon angioplasty is superior to papaverine for treatment of proximal vessel vasospasm by virtue of a more sustained effect on the vessels. Papaverine can be useful as an adjunct to balloon angioplasty and also for the treatment of distal vessels that are not accessible for balloon angioplasty.


Asunto(s)
Aneurisma Roto/complicaciones , Angioplastia de Balón , Aneurisma Intracraneal/complicaciones , Ataque Isquémico Transitorio/terapia , Papaverina/uso terapéutico , Vasodilatadores/uso terapéutico , Velocidad del Flujo Sanguíneo , Angiografía Cerebral , Circulación Cerebrovascular , Humanos , Ataque Isquémico Transitorio/diagnóstico , Ataque Isquémico Transitorio/etiología , Ataque Isquémico Transitorio/fisiopatología , Hemorragia Subaracnoidea/complicaciones , Resultado del Tratamiento , Ultrasonografía Doppler Transcraneal
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