Soleus H-Reflex Change in Poststroke Spasticity: Modulation due to Body Position

Abstract

Purpose. This study is aimed at exploring how soleus H-reflex change in poststroke patients with spasticity influenced by body position. Materials and Methods. Twenty-four stroke patients with spastic hemiplegia and twelve age-matched healthy controls were investigated. Maximal Hoffmann-reflex (Hmax) and motor potential (Mmax) were elicited at the popliteal fossa in both prone and standing positions, respectively, and the Hmax/Mmax ratio at each body position was determined. Compare changes in reflex behavior in both spastic and contralateral muscles of stroke survivors in prone and standing positions, and match healthy subjects in the same position. Results. In healthy subjects, Hmax and Hmax/Mmax ratios were significantly decreased in the standing position compared to the prone position (Hmax: p = 0.000 , Hmax/Mmax: p = 0.016 ). However, Hmax/Mmax ratios were increased in standing position on both sides in poststroke patients with spasticity (unaffected side: p = 0.006 , affected side: p = 0.095 ). The Hmax and Hmax/Mmax ratios were significantly more increased on the affected side than unaffected side irrespective of the position. Conclusions. The motor neuron excitability of both sides was not suppressed but instead upregulated in the standing position in subjects with spasticity, which may suggest that there was abnormal regulation of the Ia pathway on both sides.

Immediate Reduction in Spasticity of Ankle Plantar Flexors in a Stroke Patient after Treatment with a Spinning Permanent Magnet Device

“…According to a previous study among 24 stroke patients and 12 age-matched healthy individuals, the mean Hmax/Mmax of the tibial nerve on the affected side, with the patient in the prone position, was higher in stroke patients (37.95% ± 15.16%) than in healthy individuals (26.88% ± 11.88%). 12) The Hmax/Mmax of our patient's affected spastic leg was similar to that of stroke patients in a previous study, although it improved to some degree after SPM stimulation. We speculate that the Hmax/Mmax observed before stimulation on Day 3 was higher than that observed before stimulation on Day 1 because of a decrease in the M wave.…”

Flexor carpi radialis H-reflex in different body positions in patients with post-stroke

“…Previous research has shown obvious down-modulation of lower extremity (LE) SSR excitability in the sitting and standing positions than in the prone position in healthy subjects ( 5 ). In patients with chronic stroke, the SSR excitability in bilateral LEs was generally up-modulated when compared with healthy controls ( 7 ).…”

“…Several studies found that the soleus H-reflex varies in different body positions and is specifically down-modulated when sitting or standing compared with the prone position in healthy participants (7,8). One previous study has also shown that the soleus H-reflex was up-modulated on both sides when standing compared with the prone position in patients with spasticity after stroke (5). Collectively, most previous studies focused on the relationship between soleus H-reflex modulation and postural control in healthy adults and patients with upper motor neuron disease.…”

“…It has been reported that SSR hyperexcitability is reflected by the H-reflex in more strongly affected upper and lower extremities after stroke ( 5 , 6 ). Several studies found that the soleus H-reflex varies in different body positions and is specifically down-modulated when sitting or standing compared with the prone position in healthy participants ( 7 , 8 ).…”