Energy Costs of Spasticity in Spinal Cord Injury: A Pilot Investigation

Obesity is at epidemic proportions in the population with spinal cord injury (SCI), and is likely the mediator of the metabolic syndrome in this special population. Recent literature reviews have suggested that obesity is present in > 67% of persons with SCI. Additionally, recent studies have demonstrated the causal relationship between adipose tissue accumulation and vascular inflammation, dyslipidemia, insulin resistance / glucose intolerance, hypertension and thromboemboli.

Obesity in SCI occurs because of acute and ongoing positive energy balance, i.e., greater caloric intake than energy expenditure. Total Daily Energy Expenditure (TDEE) in SCI is reduced primarily because of muscular atrophy and diminished muscular contraction; pharmacological treatment of spasticity possibly reduces energy expenditure (EE) even further, but has not been evaluated to date. TDEE is comprised of three components: Basal Energy Expenditure (BEE), Thermic Effect of Activity (TEA) and Thermic Effect of Food (TEF). Of the three, BEE contributes the greatest amount (65-75% TDEE) and is the most sensitive to changes in spasticity.

Dampening spasticity has been reported to increase weight gain and necessitate reduced caloric intake in a child with spastic quadriplegia. Similarly, athetosis in patients with cerebral palsy increased resting metabolic rate (RMR) as compared to control subjects with no athetotic movements. Although several studies have reported energy requirements for persons with neurodevelopmental disabilities, and even SCI, however, none have attempted to measure the metabolic effect of spasticity.