Spinal muscular atrophy

The first step in treating your child is forming an accurate and complete diagnosis. To diagnose your child's SMA, your specialist at Boston Children's Hospital uses a combination of medical history, physical examination and laboratory tests.

How is spinal muscular atrophy diagnosed?

Spinal muscular atrophy is sometimes difficult to diagnose, as symptoms can resemble other conditions or medical problems. Doctors usually diagnose it after a child has suddenly or gradually shown muscle weakness and decreased muscle tone.

The work-up for a child with muscle weakness, when SMA is suspected, includes:

• a detailed physical exam
• gathering of past medical history
• gathering of family history information
• diagnostic testing
  • genetic blood tests
  • an electromyography (EMG) test that measures the electrical activity of a muscle or a group of muscles
  • in exceptionally rare cases, a child may need a muscle biopsy
  • creatine kinase (CPK) test (to distinguish from other types of muscle diseases, if necessary)
  • Type III SMA can often be misdiagnosed as muscular dystrophy.
  • SMA will result in normal or slightly elevated CPK enzyme levels while muscular dystrophy (MD) results in much higher CPK levels.

• EMG lab
  Experience counts when it comes to conducting an electromyography (EMG) test correctly and compassionately. For more than 30 years, the EMG lab has been reading EMG tests and making children feel safe and comfortable during this procedure. This test is used sometimes when SMA is suspected.

  Future of child neurology
  Children’s Hospital Boston not only provides the best child neurology care, but also trains the best doctors to continue exceptional care for your children and your children’s children. Learn more about the child neurology residency program.