The goals of this study were to characterize clinical and electrophysiologic findings of subjects with upper motor neuron disease and to explore feasibility of clinical trials in this population.
Twenty northeast amyotrophic lateral sclerosis consortium (northeast amyotrophic lateral sclerosis) sites performed chart reviews to identify active clinical pure upper motor neuron disease patients. Patients with hereditary spastic paraplegia or meeting revised El Escorial electrodiagnostic criteria for amyotrophic lateral sclerosis were excluded. Patients were classified into 2 groups according to the presence or absence of minor electromyography (EMG) abnormalities.
Two hundred thirty-three subjects with upper motor neuron disease were identified; 217 had available EMG data. Normal EMGs were seen in 140 subjects, and 77 had minor denervation. Mean disease duration was 84 (±80) months for the entire cohort with no difference seen between the 2 groups. No difference was seen in clinical symptoms, disability, or outcome measures between the 2 groups after correcting for multiple comparisons.
Minor EMG abnormalities were not associated with phenotypic differences in a clinical upper motor neuron disease population. These findings suggest that subtle EMG abnormalities can not necessarily be used as a prognostic tool in patients with clinical upper motor neuron disease. This study also demonstrates the availability of a large number of patients with upper motor neuron diseases within the northeast amyotrophic lateral sclerosis network and suggests feasibility for conducting clinical trials in this population.
*Department of Neurology, Emory University, Atlanta, GA;
†Department of Neurology, Neurology Clinical Research Institute, Massachusetts General Hospital, Boston, MA;
‡Department of Neurology, Columbia Presbyterian Medical Center, New York, NY;
§Department of Neurology, University of California, San Francisco, CA;
¶Department of Neurology, The Ohio State University, Columbus, OH;
‖Department of Neurology, Pennsylvania State University College of Medicine, Hershey, PA;
**Department of Neurology, Johns Hopkins University, Baltimore, MD;
††Department of Neurology, University of Kansas Medical Center, Kansas City, KS;
‡‡Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR;
§§Department of Neurology, Drexel University College of Medicine, Philadelphia, PA; and
¶¶Department of Neurology, University of Connecticut, Farmington, CT.
Reprints: Nazem Atassi, MD, MMSc, Neurological Clinical Research Institute (NCRI), Massachusetts General Hospital, 165 Cambridge St, Suite 600, Boston, MA 02114 (e-mail: firstname.lastname@example.org).
The authors report no conflicts of interest.
C. N. Fournier and A. Murphy Co-authors with equal contribution.