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Updated: May 16, 2026
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In Vivo Electrophysiological Measurement of Compound Muscle Action Potential from the Forelimbs in Mouse Models of Motor Neuron Degeneration
Published on: June 15, 2018
Clinical evolution of pure upper motor neuron disease/dysfunction (PUMMD)
Emanuele D'Amico1, Meredith Pasmantier, Yei-Won Lee
1Eleanor and Lou Gehrig MDA/ALS Center, Columbia University Medical Center, 710 West 168th Street, New York, NY 10032, USA.
Muscle & Nerve
|November 22, 2012
Summary
Pure upper motor neuron disease (PUMND) may progress to lower motor neuron disease (LMND). This study suggests PUMND might be an early stage of Amyotrophic Lateral Sclerosis (ALS), potentially affecting all patients eventually.
Area of Science:
- Neurology
- Neurodegenerative Diseases
Background:
- Pure upper motor neuron disease (PUMND) is defined as upper motor neuron dysfunction beyond 48 months post-symptom onset.
- Early PUMND stages are poorly understood, hindering insights into PLS and ALS mechanisms and potential protection against lower motor neuron disease (LMND).
Purpose of the Study:
- To investigate the early stages and progression of PUMND.
- To determine the relationship between PUMND and LMND, and its implications for Amyotrophic Lateral Sclerosis (ALS).
Main Methods:
- Retrospective review of 622 motor neuron disease (MND) cases over 4 years.
- Identification and follow-up of 34 patients diagnosed with PUMND.
Main Results:
- 5.4% of MND cases were identified as PUMND.
- Of 23 patients with follow-up, 57% remained PUMND, while 35% developed LMND, sometimes significantly after symptom onset (up to 127 months).
- Patients with PUMND and LMND showed greater functional impairment.
Conclusions:
- Pure lateral sclerosis (PLS) is likely part of the ALS spectrum.
- All PUMND cases may eventually progress to LMND.
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