Effects of repetitive transcranial magnetic stimulation and intensive occupational therapy on motor neuron excitability in poststroke hemiparetic patients: A neurophysiological investigation using F-wave parameters

Abstract

Background: The combination protocol of repetitive transcranial magnetic stimulation (RTMS) and intensive occupational therapy (OT) improves motor function of the paretic upper limb in poststroke patients. However, the effect of RTMS/OT on motor neuron excitability remains to be investigated. The purpose of this study was to determine the effect of 15-day application of RTMS/OT on motor neuron excitability in such patients using neurophysiological studies including F-wave parameter measurements. Subjects and Methods: Ten poststroke patients with spastic upper limb hemiparesis were studied (mean age: 57.4 ± 8.1 years, ±SD). Patients were hospitalized for 15 days to receive RTMS/OT. One session of 40-min low-frequency RTMS and two sessions of 120-min intensive OT were provided daily. Neurophysiological studies including F-wave parameters measurements were performed on the days of admission/discharge. Motor function and spasticity of the affected upper limb were evaluated on the same time points. Results: RTMS/OT significantly improved motor function of the affected upper limb. RTMS/OT decreased the modified Ashworth scale (MAS) in the affected upper limb (p < 0.05), but did not change F-wave frequency in either upper limb. However, both F-mean/M ratio and F-max/M ratio significantly decreased in the affected upper limb (all p < 0.05). Conclusions: The 15-day protocol of LF-RTMS/OT produced significant reduction of motor neuron excitability. RTMS/OT can potentially produce significant reduction in upper limb spasticity in the affected upper limb, although this finding should be confirmed in a larger number of patients.