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Review
. 2014:2014:354906.
doi: 10.1155/2014/354906. Epub 2014 Oct 30.

Pathophysiology of spasticity: implications for neurorehabilitation

Carlo Trompetto  1 , Lucio Marinelli  1 , Laura Mori  1 , Elisa Pelosin  1 , Antonio Currà  2 , Luigi Molfetta  1 , Giovanni Abbruzzese  1
Affiliations
Review

Pathophysiology of spasticity: implications for neurorehabilitation

Carlo Trompetto et al. Biomed Res Int. 2014.

Abstract

Spasticity is the velocity-dependent increase in muscle tone due to the exaggeration of stretch reflex. It is only one of the several components of the upper motor neuron syndrome (UMNS). The central lesion causing the UMNS disrupts the balance of supraspinal inhibitory and excitatory inputs directed to the spinal cord, leading to a state of disinhibition of the stretch reflex. However, the delay between the acute neurological insult (trauma or stroke) and the appearance of spasticity argues against it simply being a release phenomenon and suggests some sort of plastic changes, occurring in the spinal cord and also in the brain. An important plastic change in the spinal cord could be the progressive reduction of postactivation depression due to limb immobilization. As well as hyperexcitable stretch reflexes, secondary soft tissue changes in the paretic limbs enhance muscle resistance to passive displacements. Therefore, in patients with UMNS, hypertonia can be divided into two components: hypertonia mediated by the stretch reflex, which corresponds to spasticity, and hypertonia due to soft tissue changes, which is often referred as nonreflex hypertonia or intrinsic hypertonia. Compelling evidences state that limb mobilisation in patients with UMNS is essential to prevent and treat both spasticity and intrinsic hypertonia.

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Figures

Figure 1
Figure 1
Rectified electromyographic activity recorded from the flexor carpi radialis of a patient with left spastic hemiparesis from right cerebral ischaemic stroke. The muscle has been stretched throughout a range of 60° (dynamic phase) and maintained elongated afterward (static phase). The electromyographic activity not only is present during the dynamic phase, reflecting the typical stretch reflex, but persists also during the static phase.
Figure 2
Figure 2
Schematic representation of the descending pathways modulating the stretch reflex circuitry (see text).
See this image and copyright information in PMC

References

    1. Lance J. W. Symposium synopsis. In: Feldman R. G., Young R. R., Koella W. P., editors. Spasticity: Disordered Motor Control. 1980. pp. 485–494.
    1. Burke D., Gillies J. D., Lance J. W. The quadriceps stretch reflex in human spasticity. Journal of Neurology Neurosurgery and Psychiatry. 1970;33(2):216–223. doi: 10.1136/jnnp.33.2.216. - DOI - PMC - PubMed
    1. Tardieu G., Tardieu C., Colbeau Justin P., Bret M. D. Effects of muscle length on an increased stretch reflex in children with cerebral palsy. Journal of Neurology Neurosurgery and Psychiatry. 1982;45(4):348–352. doi: 10.1136/jnnp.45.4.348. - DOI - PMC - PubMed
    1. Rymer W. Z., Houk J. C., Crago P. E. Mechanisms of the clasp-knife reflex studied in an animal model. Experimental Brain Research. 1979;37(1):93–113. doi: 10.1007/BF01474257. - DOI - PubMed
    1. Kamper D. G., Schmit B. D., Rymer W. Z. Effect of muscle biomechanics on the quantification of spasticity. Annals of Biomedical Engineering. 2001;29(12):1122–1134. doi: 10.1114/1.1424918. - DOI - PubMed

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