Spasticity Study Group

This study group has been formed to develop international collaborative research in the field of spasticity, including that after stroke. Post-stroke spasticity is rapidly increasing in prevalence in many countries, either developed or developing.  Among them, Asian countries would suffer most, because of their explosion of the aged population in the future (1) (Kaji Neurology 2015).

The prevalence of spasticity after stroke is estimated to be 30-49% of the survivors, and, the stroke spasticity is the leading cause of disability in Japan, which has now the highest aging rate among other countries.The social cost for caring for stroke survivors is soaring, with these patients losing their independence and self-esteem. Therapeutic measures such as botulinum toxin injection are now available in some countries(2), but its best clinical uses are still unexplored. In addition, spasticity is a major cause of disability in other neurological disorders such as hereditary spastic paraplegias (HSPs) and cerebral palsy (CP).

There has been a dispute as to whether spasticity is a part of movement disorder or not. Some physiological features are shared by dystonia, in that there is co-contraction of agonist and antagonist muscles(3) and active function can be regained in severely spastic limbs using botulinum toxin injection (4-6)(Kaji 2013, Kaji et al. 2010), yet dystonia differs from spasticity in that the former is not associated with weakness, which is usually seen in spasticity[e1] .  Therapeutic approaches used to treat dystonia are thus promising for treating the large number of people with stroke. Basic, as well as clinical studies for pathophysiology, diagnosis and treatment are needed.

With the recent advances in neurorehabilitation, some robots (e.g. ReWalk, Hybrid Assisted Limb) are being tested for its approval as a medical devise(7), but they have not been successful unless being combined with botulinum toxin injections.

Currently, the Spasticity Study Group aims to bring together researchers, patient groups, health professionals and industries; as well as to stimulate researches to improve the understanding of spasticity as a treatable movement disorder and to explore therapeutic options of botulinum toxin alone or its combined use with rehabilitation. Such an international effort meets the mission of MDS and in collaboration with WHO, should greatly contribute the ever-increasing social medical needs as the aging accelerates in many countries.