RESUMO
Radiotracer imaging (RTI) of the nigrostriatal dopaminergic system is a widely used but controversial biomarker in Parkinson disease (PD). Here the authors review the concepts of biomarker development and the evidence to support the use of four radiotracers as biomarkers in PD: [18F]fluorodopa PET, (+)-[11C]dihydrotetrabenazine PET, [123I]beta-CIT SPECT, and [18F]fluorodeoxyglucose PET. Biomarkers used to study disease biology and facilitate drug discovery and early human trials rely on evidence that they are measuring relevant biologic processes. The four tracers fulfill this criterion, although they do not measure the number or density of dopaminergic neurons. Biomarkers used as diagnostic tests, prognostic tools, or surrogate endpoints must not only have biologic relevance but also a strong linkage to the clinical outcome of interest. No radiotracers fulfill these criteria, and current evidence does not support the use of imaging as a diagnostic tool in clinical practice or as a surrogate endpoint in clinical trials. Mechanistic information added by RTI to clinical trials may be difficult to interpret because of uncertainty about the interaction between the interventions and the tracer.
Assuntos
Corpo Estriado/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Compostos Radiofarmacêuticos , Substância Negra/diagnóstico por imagem , Biomarcadores , Biotransformação , Barreira Hematoencefálica , Radioisótopos de Carbono/farmacocinética , Ensaios Clínicos como Assunto/métodos , Cocaína/análogos & derivados , Cocaína/farmacocinética , Corpo Estriado/metabolismo , Di-Hidroxifenilalanina/análogos & derivados , Di-Hidroxifenilalanina/farmacocinética , Dopamina/metabolismo , Radioisótopos de Flúor/farmacocinética , Fluordesoxiglucose F18/farmacocinética , Previsões , Humanos , Radioisótopos do Iodo/farmacocinética , Neurônios/química , Neurônios/diagnóstico por imagem , Doença de Parkinson/diagnóstico , Doença de Parkinson/terapia , Tomografia por Emissão de Pósitrons , Prognóstico , Compostos Radiofarmacêuticos/farmacocinética , Receptores Dopaminérgicos/metabolismo , Substância Negra/metabolismo , Tetrabenazina/análogos & derivados , Tetrabenazina/farmacocinética , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Nine patients with chronic severe pain due to end-stage traction neuritis of an intact peripheral nerve underwent external neurolysis and epineurectomy or epineurectomy and internal neurolysis followed by circumferential wrapping of the involved segment of nerve with a pedicle flap or free flap consisting of either subcutaneous fat tissue, fascia, or muscle. Seven patients (77%) followed for between 1 and 5 years had substantial relief of pain. Two patients (22%) had no decrease in their pain at all. Circumferential wrapping may cushion the nerve from external pressure on the overlying skin, may isolate the nerve from the traction forces of adjacent moving tendons to allow improved gliding of the nerve, and may promote revascularization of a scarred nerve. This surgery may be indicated for patients with persistent pain following multiple carpal tunnel or cubital tunnel surgeries.
Assuntos
Nervo Mediano/lesões , Neurite (Inflamação)/cirurgia , Complicações Pós-Operatórias/cirurgia , Nervo Radial/lesões , Terapia de Salvação/métodos , Retalhos Cirúrgicos/métodos , Nervo Tibial/lesões , Nervo Ulnar/lesões , Adulto , Doença Crônica , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes de Compressão Nervosa/cirurgia , Neurite (Inflamação)/etiologia , Dor/etiologia , Complicações Pós-Operatórias/etiologia , Resultado do TratamentoRESUMO
Clinical evidence is presented to support the contention that the sternocleidomastoid muscle is innervated primarily by undecussated fibers from the ipsilateral hemisphere. Stroke patients often show contralateral hemiparesis accompanied by weakness in head turning to the side of the paresis.