RESUMEN
Electrical stimulation (ES) of lumbosacral nerve roots using a needle electrode inserted to the laminar level at the midline of Th12-L1 or L1-2 intervertebral interspace, was compared with magnetic stimulation using a 9-cm diameter coil (MCS) at the L3-4 or L4-5 spine levels, Compound muscle action potentials (CMAP) were superficially recorded from homologous muscles in both sides in 15 normal control subjects and in 20 patients with lumbosacral radiculopathy. Soleus muscles were used for S1, tibialis anterior (TA) for L5, and rectus femoris (RF) muscles for L4 roots. According to the clinical or radiological diagnosis (CAT, MRI and/or myelography) conventional needle EMG was capable to localise the root lesion in 16 of 20 patients (80%) and ES localised the root involvement in 18 of 20 patients (90%); the diagnostic value of MCS was lower, about 65% (13 of 20 patients). Although ES is uncomfortable and invasive, it is superior to needle EMG in localising unilateral or multiple lumbosacral root involvement. At present, MCS is not suitable for the diagnosis of lumbar radiculopathy.
Asunto(s)
Estimulación Eléctrica/instrumentación , Campos Electromagnéticos , Enfermedades del Sistema Nervioso Periférico/diagnóstico , Raíces Nerviosas Espinales/fisiopatología , Adulto , Anciano , Electromiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculos/inervación , Síndromes de Compresión Nerviosa/diagnóstico , Síndromes de Compresión Nerviosa/fisiopatología , Enfermedades del Sistema Nervioso Periférico/fisiopatología , Tiempo de Reacción/fisiología , Reflejo Anormal/fisiología , Ciática/diagnóstico , Ciática/fisiopatologíaRESUMEN
Needle electrical stimulation of the lumbosacral roots at the laminar level of the Th12-L1 or L1-2 intervertebral spaces were performed in 24 normal subjects and 58 patients with various kinds of lumbar radiculopathy (unilateral L4, L5 and S1 herniated nucleus pulposus and lumber stenosis). The root stimulation method was compared with conventional needle EMG. Lumber electrical stimulation showed root abnormalities objectively in 80% of patients while the diagnostic value of needle EMG was 65%. Therefore, electrical root stimulation is superior to routine EMG for localizing lumbar root involvement. However, the only needle EMG demonstrated the root pathology in 7 cases (12%) and single electrophysiological abnormality was found by the root stimulation in 16 cases (27%). Thus, both electrophysiological methods should be complementary to each other in evaluation of the lumbar radioculopathy.