Spinal cord injury and electric stimulation: Types and characteristics of spasticity

Spasticity manifests itself in manifold features. In spinal cord injury (SCI) patients it can appear with different peculiarities. We studied the spasticity of 17 SCI patients in relation to their responses to therapeutic electrical stimulation (TES). We distinguished 3 types of spinal cord spasticity. The first and most frequent type (11 out of 17) is clinically characterized by clonic contractions of the antigravitatory muscles in the lower limbs (mostly quadriceps and soleus muscles), sometimes associated with tonic or clonic spasms in the trunk in the cervical level lesions; this kind of contractions are usually remarkably reduced (10 out of 11) by TES applied on quadriceps and hamstring muscles and on the peroneal nerve. The second type was observed in 1 of the 17 patients and it consists of strong tonic extensor spasm of trunk and lower limbs. This form of true spasticity is very similar to the hemiplegic spasticity and is presented by patients in which the lesions affected also, in some extent, the supra-tentorial nervous formations (viral lesions). II benefits greatly from TES of antagonistic muscles. The third form was observed in 2 cervical patients and is typified by severe spasms, mostly tonic, prevalently in flexion in the lower limbs and extension in the trunk; this form is not sensitive at all to TES. The reduction of contractions and spasticity in the first two types was usually, but not always, of short term. A consequence of this study is that we have to re-consider what we call spasticity in SCI patients.