The clinical and electrodiagnostic characteristics of Pompe disease with post-enzyme replacement therapy findings

ObjectivePompe disease is a neuromuscular disorder that was progressive and fatal prior to enzyme replacement therapy (ERT). The advent of treatment has made early recognition imperative. Electrodiagnostic (EDx) studies represent a valuable diagnostic tool in Pompe disease, but there has been little contemporary data.MethodsThe records of 29 patients with Pompe disease who had undergone EDx evaluation at Duke University Medical Center from 1999 to 2010 were reviewed.ResultsSeventeen children and twelve adults comprised the group. The clinical characteristics of both groups did not differ from expected. Needle electromyography demonstrated spontaneous activity (SA) in 80% of children and 83% of adults. Myotonic discharges were found in 53% of children and 72% of adults, often isolated to the paraspinal muscles in adults. Eight patients had EDx studies performed after ERT with 3 showing improvement after therapy, despite clinical improvement in 6 of 8.ConclusionsEDx studies remain a helpful tool in diagnosing Pompe disease, but do not appear to be sensitive for monitoring response to ERT based upon this limited sample.SignificanceParaspinal examination is necessary in adults with symptoms suggestive of Pompe disease, as abnormalities may be isolated to this region. Standard EDx studies are not sufficient to monitor early response to ERT and further research on potential biomarkers is needed.

► Electrodiagnostic abnormalities are present in most patients with Pompe disease. ► Myotonic discharges and other abnormalities may be isolated to the paraspinal muscles. ► Needle electrode examination of paraspinal muscles is strongly recommended in adults.