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Washington University NF Center Researchers Define Measures for Evaluating Low Tone Muscle in Children with NF1

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Courtney Dunn, PT, DPT, screens children with NF1 in clinic for hypotonia and developmental delays.


Nearly half of all children with NF1 have low tone (hypotonia). A recent study at the Washington University NF Center suggested that children with both NF1 and hypotonia may be at greater risk for developing a brain tumor. However, there are few objective methods for evaluating hypotonia.
To address this need, Courtney Dunn, PT DPT, led a study designed to establish criteria for assessing hypotonia in children with NF1. She found that hypotonia could be reliably diagnosed if a child’s head lags at or behind the shoulders when pulled up from a prone position (pull-to-sit-test) and the child has increased flexibility at the hip joint (hip range of motion).
Dr. Dunn is currently using these findings in a prospective study to determine whether hypotonia can be used to predict which children with NF1 are at greatest risk for developing brain tumors.
Soucy EA, Wessel LE, Gao F, Albers AC, Gutmann DH, Dunn CM. A pilot study for evaluation of hypotonia in children with neurofibromatosis type 1. J. Child. Neurol. (in press)