Prospective study of spinal muscular atrophy before age 6 years. DCN/SMA Group

Pediatr Neurol. 1993 May-Jun;9(3):187-93. doi: 10.1016/0887-8994(93)90082-n.


Spinal muscular atrophy (SMA) is a common neuromuscular disorder of childhood, associated with a high mortality rate during the first 2 years of life. Most practitioners expect patients with SMA to follow a progressive course with loss of muscle strength and function over 2-10 years. Counselling sessions with parents frequently emphasize the high mortality rate and risk for respiratory failure. The progressive nature of SMA has been attributed to the loss of motor neurons. Fifty-eight children, ages 6 years and younger, were examined between January, 1987, and April, 1992, as part of a large, multicenter collaborative study of SMA. Muscle function was evaluated at regular intervals using a standardized protocol that was demonstrated to be reliable. We determined a prevalence of 56% for tongue fasciculations, a prevalence of 22% for facial weakness, and persistent deep tendon reflexes in one patient. Improved motor function and acquired milestones during the study were documented. This work should contribute toward a better understanding of the natural history of SMA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Male
  • Motor Skills / physiology
  • Muscle Contraction / physiology
  • Neurologic Examination
  • Prospective Studies
  • Range of Motion, Articular / physiology
  • Reflex, Stretch / physiology
  • Spinal Muscular Atrophies of Childhood / diagnosis*
  • Spinal Muscular Atrophies of Childhood / physiopathology
  • Sucking Behavior / physiology