A test called the electromyogram (EMG) is
better than MRI at accurately diagnosing spinal stenosis,
a narrowing of spaces in the spine that causes pressure
on the spinal cord and nerves, researchers report.
Spinal stenosis can result in debilitating back pain
or paralysis if left untreated.
EMG was developed during World War II but, until now,
there have been no controlled studies of EMG for spinal
stenosis. For their study, researchers at the University
of Michigan Health System, Ann Arbor, used EMG to examine
150 back pain patients.
They found that EMG can reduce misdiagnosis of low back
pain and other common neuromuscular conditions that cause
similar symptoms. More accurate diagnosis can help avoid
unnecessary back surgery.
The study authors concluded that EMG is the only way
to prevent misdiagnosis, and that MRI should not be used
as the only proof that a person has spinal stenosis. The
study appears in this month's issue of Spine.
"EMG plays an important role in the diagnosis of back
pain because, unlike MRI, EMG is more than a picture of
a nerve, it can test nerve function and show if there
is actual nerve damage," study author Dr. Andrew Haig,
an associate professor in the department of physical medicine
and rehabilitation, said in a prepared statement.
"The EMG is really going to help doctors to avoid unnecessary
procedures because it proves that there is nerve damage
in the people who clearly have it and can accurately diagnosis
spinal stenosis," Haig said.
