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RESEARCH PRODUCT

Analysis of F response in upper motoneurone lesions

Domenico Di RaimondoA. ModicaBrigida Fierro

subject

AdultMaleReflex Stretchmedicine.medical_specialtyWeaknessHemiplegiaPhysical examinationStimulationElectromyographyFunctional LateralityF waveInternal medicineReaction TimemedicineHumansTibial nerveStrokeUlnar NerveAgedAged 80 and overMotor Neuronsmedicine.diagnostic_testElectromyographyMusclesNeuromuscular DiseasesGeneral MedicineMiddle Agedmedicine.diseaseSurgeryCerebrovascular DisordersNeurologyMuscle TonusCardiologyReflexFemaleNeurology (clinical)Tibial Nervemedicine.symptomPsychology

description

The F response can provide a measure of motoneurone excitability (MNE) and so it may be used to investigate upper motoneurone disorders. This report studies the F-wave configuration in patients with stroke to evaluate the changes of the central excitability of the motoneurones at different times after an acute cerebral insult. Various parameters of the F response, including amplitude (absolute and F%/M), duration, and persistence have been determined in 26 patients with unilateral hemiplegia and in 32 healthy subjects of both sexes in the same age range. The investigation was carried out applying a series of 20 supramaximal stimuli at 0.5 Hz on tibial and ulnar nerves bilaterally. In all patients a detailed clinical examination and a CT scan were performed. Our results indicate that an initial stage of reduced spinal motoneuron excitability evidenced by a decreased F amplitude and persistence was present in the early phases after a stroke, followed within 90 days by an enhanced MNE. Moreover, F-wave amplitude shows a positive correlation with weakness and increased tone.

https://doi.org/10.1111/j.1600-0404.1990.tb03311.x