Antispastic Effect of Transcranial Magnetic Stimulation in Patients With Cerebral and Spinal Spasticity

Spasticity associated with excessive activation of the stretch reflex, the second occurs when the upper motor neuron injury (Young, 1994), which leads to a reduction of spinal inhibition, manifested in the reduction of presynaptic inhibition of Ia afferents coming from muscle spindles flexor (Nielsen et al., 1995 ) and disinapticheskogo reciprocal Ia inhibition of antagonist muscle afferents (Meunier and Pierrot-Deseilligny, 1998; Nielsen et al., 2007), abnormal activity of Ib afferents from tendon Golgi complex (autogenous Ib inhibition), resulting in relief instead of inhibiting alpha-motoneurons ( Delwaide and Olivier, 1988), the deterioration of motor neurons inhibit rekkurentnogo Renshaw cells (Katz and Pier-rot-Deseilligny, 1982, 1999).

There are two basic models of spasticity: cerebral (hemiplegic) and spinal (paraplegicheskaya) (Nikitin, 2005). Cerebral model shines through direct injury of the brain and is characterized by increased excitability of the monosynaptic reflexes with quick reflexes and the development of pathological characteristic hemiplegic posture. Model is characterized by spinal spasticity opposite lower segmental inhibition polysynaptic reflexes slow increase of nervous excitability due to the mechanism of cumulative excitation overexcitation of the flexor and extensor muscles, as well as expansion of the area of segmental responses (Nikitin, 2005). According to recent studies the mechanisms of cerebral and spinal spasticity are different.

According to most researchers increased activity (excitability) of the motor cortex can increase the inhibitory effect of the corticospinal tract and reduce hyperactivity gamma and alpha motor neurons (Valero-Cabre, Pascual-Leone, 2005; Valero-Cabre et al., 2001; Valle et al. , 2007). According to this statement is a special place in the methods of correction of spasticity can take neuromodulation techniques, one of which is a rhythmic transcranial magnetic stimulation (RTMS). In the widely discussed mechanisms of action RTMS to reduce spasticity, explaining its efficacy in MS, spinal cord injury, stroke and cerebral palsy (Nielsen et al., 1996; Kumru et al., 2010; Mori et al., 2011). However, to date, conclusive evidence explaining the mechanisms reduce both spinal and cerebral spasticity under the RTMS not.

From this point of view, it is particularly interesting to study the excitability of the motor cortex by paired TMS to the study of phenomena vnutrikorkovogo inhibition of motor response (SISI in English literature) and vnutrikorkovogo facilitate induced motor response (ICF in the English language), which allow to study the mechanisms of differentiated inhibition and excitation in central nervous system at different levels (Chen et al., 1998).

Transcranial magnetic stimulation (TMS) is a technique that, on the one hand, it can be considered as a way to assess neyroplasticheskih processes, and on the other, the special modes, as neyromoduliruyuschego impact.