Voluntary ankle flexor activity and adaptive coactivation gain is decreased by spasticity during subacute spinal cord injury.

Although spasticity has been defined as an increase in velocity-dependent stretch reflexes and muscle hypertonia during passive movement, the measurement of flexor muscle paresis may better characterize the negative impact of this syndrome on residual motor function following incomplete spinal cord injury (iSCI). In this longitudinal study Tibialis Anterior (TA) muscle paresis produced by a loss in maximal voluntary contraction during dorsiflexion and ankle flexor muscle coactivation during ramp-and-hold controlled plantarflexion was measured in ten patients during subacute iSCI. Tibialis Anterior activity was measured at approximately two-week intervals between 3-5 months following iSCI in subjects with or without spasticity, characterized by lower-limb muscle hypertonia and/or involuntary spasms. Following iSCI, maximal voluntary contraction ankle flexor activity was lower than that recorded from healthy subjects, and was further attenuated by the presence of spasticity. Furthermore the initially high percentage value of TA coactivation increased at 75% but not at 25% maximal voluntary torque (MVT), reflected by an increase in TA coactivation gain (75%/25% MVT) from 2.5+/-0.4 to 7.5+/-1.9, well above the control level of 2.9+/-0.2. In contrast contraction-dependent TA coactivation gain decreased from 2.4+/-0.3 to 1.4+/-0.1 during spasticity. In conclusion the adaptive increase in TA coactivation gain observed in this pilot study during subacute iSCI was also sensitive to the presence of spasticity. The successful early diagnosis and treatment of spasticity would be expected to further preserve and promote adaptive motor function during subacute iSCI neurorehabilitation.

Tracheostomy ventilation versus diaphragmatic pacemaker ventilation in high spinal cord injury.

We have made a retrospective comparative study of patients with spinal cord injury, nine with a diaphragmatic pacemaker and 13 with mechanical ventilation. Clinical outcome, cost and subjective satisfaction with both modalities have been evaluated. The functional status was the same with both types of treatment. Proper management of an electric wheelchair and optimal phonation were attained, respectively, in 100% and 89% of pacers and in 77% and 77% of mechanically ventilated. The rate of hospital discharge and satisfaction with the treatment were significantly better for pacers. The time devoted to ventilatory assistance and cost were also more favourable in this group.

Incidence and risk factors in the appearance of heterotopic ossification in spinal cord injury.

Heterotopic ossification (HO) is a frequent complication in patients with a spinal cord injury (SCI), although the aetiology is unknown. A study was undertaken of 654 SCI patients with traumatic aetiology, admitted for the first time to the Hospital Nacional de Paraplejicos, Toledo, during 1988 and 1989. Of the total number of patients, 85 (13%) were diagnosed HO and 569 without HO. The diagnosis was mainly achieved by x-ray studies and clinical signs. From the 569 patients with traumatic aetiology without HO, 44 were selected at random, as were 44 of the 85 patients with HO. The mean time lapse between the occurrence of the accident and admission for patients with HO was 40.79 days (typical deviation (TD) = 45.2), and for patients without HO was 32.84 (TD = 38) days, resulting in a value of F = 0.796 through analysis of variance, which is not a statistically significant variation between the 2 groups. In both groups we have taken account of the following variables: age at time of lesion, lesion level, type of lesion (complete or incomplete), spasticity, urinary tract complications, deep vein thrombosis, important associated injuries occurring at the moment of lesion, time elapsed before admission and the existence of pressure sores. In those SCI patients with HO the number of ossifications and their localisations were also verified. By use of the chi square test (X2) over all 9 variables which were studied, we found that 3 variables (complete spinal lesion, presence of pressure sores and spasticity) were significantly related to HO formation.(ABSTRACT TRUNCATED AT 250 WORDS)