Answer to Question 1
Weight/height reference standard limitations: Due to the altered growth patterns typically seen in CP patients, comparing them with the WHO and CDC growth charts is not a great representation of their relative growth. Additionally, the specialized growth charts available for CP patients based upon the GMFCS was constructed from a small sample size and, due to the heterogeneity within this population, does not adequately provide a standard for how these children should grow.
Interpretation of BMI percentiles should be used cautiously in this population due to reduced lean body mass growth (bone mineral mass and skeletal muscle) in comparison to some CP patient's potential to accumulate body fat.
Instead of relying primarily on percentiles to interpret growth, identifying any deviations from the patient's typical growth patterns or a decrease in growth velocity may be a more effective way to determine poor growth.
Answer to Question 2
Gastric emptying involves complex communication (as discussed in question 1) among hormones, muscles and the nervous system. An abnormality in any one of these systems can contribute to gastroparesis. Gastroparesis is commonly seen with autonomic nerve damage related to diabetes or as a post-surgical complication. Other cases of gastroparesis are designated as idiopathic.