RESUMEN
BACKGROUND: The etiology of Bell's palsy can vary but anterograde axonal degeneration may delay spontaneous functional recovery leading the necessity of therapeutic interventions. Corticotherapy and/or complementary rehabilitation interventions have been employed. Thus the natural history of the disease reports to a neurotrophic resistance of adult facial motoneurons leading a favorable evolution however the related molecular mechanisms that might be therapeutically addressed in the resistant cases are not known. Fibroblast growth factor-2 (FGF-2) pathway signaling is a potential candidate for therapeutic development because its role on wound repair and autocrine/paracrine trophic mechanisms in the lesioned nervous system. METHODS: Adult rats received unilateral facial nerve crush, transection with amputation of nerve branches, or sham operation. Other group of unlesioned rats received a daily functional electrical stimulation in the levator labii superioris muscle (1 mA, 30 Hz, square wave) or systemic corticosterone (10 mgkg-1). Animals were sacrificed seven days later. RESULTS: Crush and transection lesions promoted no changes in the number of neurons but increased the neurofilament in the neuronal neuropil of axotomized facial nuclei. Axotomy also elevated the number of GFAP astrocytes (143% after crush; 277% after transection) and nuclear FGF-2 (57% after transection) in astrocytes (confirmed by two-color immunoperoxidase) in the ipsilateral facial nucleus. Image analysis reveled that a seven days functional electrical stimulation or corticosterone led to elevations of FGF-2 in the cytoplasm of neurons and in the nucleus of reactive astrocytes, respectively, without astrocytic reaction. CONCLUSION: FGF-2 may exert paracrine/autocrine trophic actions in the facial nucleus and may be relevant as a therapeutic target to Bell's palsy.
RESUMEN
PURPOSE: We preliminarily investigated the relevance of performing digital subtraction angiography (DSA) in addition to magnetic resonance angiography (MRA) in definition of ischemic stroke etiology in young patients. METHOD: DSAs and MRAs from 17 young patients with nonlacunar ischemic stroke were blindly analyzed and their impact on stroke management was evaluated. RESULTS: Etiologies were the same considering results of either DSA or MRA in 12/17 cases. In 15/17 patients no changes would have been made in treatment, regardless of the modality of angiography considered. CONCLUSION: These preliminary results suggest that DSA may be redundant in two thirds of ischemic strokes in young patients. Further larger prospective studies are necessary to determine indications of DSA in this age group.
Asunto(s)
Angiografía de Substracción Digital , Ataque Isquémico Transitorio/diagnóstico , Angiografía por Resonancia Magnética , Accidente Cerebrovascular/diagnóstico , Adolescente , Adulto , Femenino , Humanos , Ataque Isquémico Transitorio/diagnóstico por imagen , Ataque Isquémico Transitorio/etiología , Masculino , Reproducibilidad de los Resultados , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/etiologíaRESUMEN
PROPÓSITO DO ESTUDO: Investigar de forma preliminar a relevância da realização de angiografia digital (AD) adicionalmente a angioressonância (AR) na definição de etiologias de acidente vascular cerebral isquêmico (AVCI) em pacientes jovens. MÉTODO: ADs e ARs de 17 pacientes jovens com AVCIs não-lacunares foram analisadas. Avaliamos o impacto destes exames no manejo clínico dos casos. RESULTADOS: Em 12/17 casos, as etiologias dos AVCIs de acordo com os resultados de AD ou de AR foram idênticas. Em 15/17 pacientes, nenhuma mudança de conduta terapêutica seria realizada, independentemente da modalidade de exame considerada. CONCLUSÃO: Estes resultados preliminares sugerem que os resultados da AD podem ser redundantes em relação à AR em até dois terços dos pacientes jovens com AVCI. Estudos prospectivos maiores são necessários para otimizar o estabelecimento de indicações de AD nesta faixa etária.