Botulinum A toxin (Botox) is used for the treatment of many muscular dystonias. However, the relief of the sustained and abnormal postures induced by Botox administration is not fully explained. In this work the possibility was considered that Botox can produce a block not only at the alpha motor endings, but also at the gamma motor endings, consequently reducing the spindle inflow to the alpha motoneurons, which have a great role in maintaining the tonic myotatic reflex. Jaw muscle spindle discharge was recorded before and after Botox injection in the deep masseter muscle. The drug consistently reduced the spindle afferent discharge. Such an effect is suggested to be direct on gamma endings as: i) muscle tension was not modified by Botox during the recording time; ii) saline administration never changed the spindle discharge. The Botox effect on muscle spindles suggests that the relief from dystonias could be due not only to a partial motor paralysis, but also to a decrease of the reflex muscular tone.

rMV with PT may be used as a nonpharmacological intervention in the neurorehabilitation of mild to moderate hemiparesis.

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Surgical reconstruction of the anterior cruciate ligament (ACL) may reduce, but it does not always eliminate, knee and body instability because of a persisting proprioceptive deficit. In order to enhance body stability, a new protocol of treatment has been proposed consisting of mechanical vibration (100 Hz frequency and < 20 microm amplitude) of the quadriceps muscle in the leg that has undergone ACL reconstruction. In our trials, stimulation was performed when the quadriceps muscle was kept isometrically contracted. Treatment was started one month after surgery. Vibration was applied for short periods over three consecutive days. Nine months after treatment, postural stability was re-evaluated with the subjects standing on one leg with open and with closed eyes. The postural stability of the subjects having undergone vibration treatment, standing on the operated leg was significantly improved one day after treatment when evaluated as mean of speed and elliptic area of the center of pressure. The improvement persisted and increased during the following weeks. Peak torques of the operated leg extensor muscles also increased and reached values close to that of the leg, which had not been operated. Conversely, the balance of the untreated subjects standing on the operated leg did not improve and the restoration of the extensor muscle peak torque was poor. It is concluded that short lasting proprioceptive activation by vibration may lead to a faster and more complete equilibrium recovery probably by permanently changing the network controlling knee posture.

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