TY - JOUR
T1 - Soleus H-reflex tests in spasticity and dystonia
T2 - A computerized analysis
AU - Bour, L.J.
AU - Ongerboer de Visser, B.W.
AU - Koelman, J.H.T.M.
AU - van Bruggen, G.J.
AU - Speelman, J.D.
PY - 1991
Y1 - 1991
N2 - In 54 healthy individuals, and in 25 spastic and 7 dystonic subjects, soleus H-reflex vibratory inhibition, H M ratio, and homonymous recovery curves obtained at two stimulus intensity levels were investigated in the same subject. In spasticity, the most prominent changes consist of a diminution of the vibratory inhibition at stimulus intensities lower than needed for a maximum H-reflex and an increase in the H M ratio. These results suggest that presynaptic inhibition is reduced mainly at low-intensity levels and that excitability of motoneurons is increased. Recovery curves in spasticity do not show such significant changes as found for the recruitment curves. In dystonia, prominent changes occur in the late facilitatory phase of the recovery curve obtained at 0.5 Hmax stimulus intensity, suggesting increased interneuronal activity. Vibratory suppression may be diminished, but H M ratio is unaltered. A multivariate analysis was used to identify variables that discriminated between control, spastic, and dystonic subjects. The analysis yielded two canonical variables that are a linear combination of four H-reflex variables that contribute significantly to the group classification. Based on these two canonical variables, each group can be properly differentiated quantitatively.
AB - In 54 healthy individuals, and in 25 spastic and 7 dystonic subjects, soleus H-reflex vibratory inhibition, H M ratio, and homonymous recovery curves obtained at two stimulus intensity levels were investigated in the same subject. In spasticity, the most prominent changes consist of a diminution of the vibratory inhibition at stimulus intensities lower than needed for a maximum H-reflex and an increase in the H M ratio. These results suggest that presynaptic inhibition is reduced mainly at low-intensity levels and that excitability of motoneurons is increased. Recovery curves in spasticity do not show such significant changes as found for the recruitment curves. In dystonia, prominent changes occur in the late facilitatory phase of the recovery curve obtained at 0.5 Hmax stimulus intensity, suggesting increased interneuronal activity. Vibratory suppression may be diminished, but H M ratio is unaltered. A multivariate analysis was used to identify variables that discriminated between control, spastic, and dystonic subjects. The analysis yielded two canonical variables that are a linear combination of four H-reflex variables that contribute significantly to the group classification. Based on these two canonical variables, each group can be properly differentiated quantitatively.
KW - Dystonia
KW - Recovery
KW - Recruitment
KW - Soleus H-reflex
KW - Spasticity
UR - http://www.scopus.com/inward/record.url?scp=0003084407&partnerID=8YFLogxK
U2 - 10.1016/1050-6411(91)90022-W
DO - 10.1016/1050-6411(91)90022-W
M3 - Article
AN - SCOPUS:0003084407
SN - 1050-6411
VL - 1
SP - 9
EP - 19
JO - Journal of electromyography and kinesiology
JF - Journal of electromyography and kinesiology
IS - 1
ER -