NeuroMap System

Clinical Use Case Comparison

Neuromuscular diseases lead to abnormal patterns of motor unit behavior that are typically investigated using invasive needle procedures.

For instance, neuropathic diseases are known to result in sparse and abnormally large motor unit action potential amplitudes present at low efforts – indicating motoneuron loss and motor unit reinnervation.

Objective: Demonstrate the ability of the NeuroMap system to provide a non-invasive measures of disease-induced abnormalities in motor unit behavior.

Acknowledgements
Clinical Use Case Comparison
Surface EMG - Control, Neuropathy

Methods

The First Dorsal Interosseous muscle of the hand was studied during at low (10% max) and high (80% max) force contractions, and the shape of individual motor unit action potentials was extracted in both control and neuropathic individuals.

Results

The NeuroMap system is able to identify known abnormalities in motor unit action potential shapes that occur as a result of neurogenic processes.

Importantly, results proved consistent with known clinical history of the patients and needle EMG results.

Needle EMG outcomes are based on data collected at Emory University and Baystate Medical Center clinical sites, and on historical data such as: Nikolic M., Detailed Analysis of Clinical Electromyography Signals EMG Decomposition, Findings and Firing Pattern Analysis in Controls and Patients with Myopathy and Amytrophic Lateral Sclerosis. PhD Thesis, Faculty of Health Science, University of Copenhagen, 2001.

Other References

Miller et al. Examination of muscle composition and motor unit behavior of the first dorsal interosseous of normal and overweight children. J Neurophysiol 2018.

Sterczala et al. Age-related differences in the motor unit action potential size in relation to recruitment threshold. Clin Physiol Funct Imaging 2017.

Miller et al. Time-related changes in firing rates are influenced by recruitment threshold and twitch force potentiation in the first dorsal interosseous. Exp Physiol 2017.

Pope et al. Action potential amplitude as a noninvasive indicator of motor unit-specific hypertrophy. J Neurophysiol 2016.

Trevino et al. The influence of the contractile properties of muscle on motor unit firing rates during a moderate contraction intensity in vivo. J Neurophysiol 2016.

Herda et al. The change in motor unit firing rates at derecruitment relative to recruitment is correlated with type I myosin heavy chain isoform content of the vastus lateralis in vivo. Acta Physiol 2015.

Trevino et al. The effects of poliomyelitis on motor unit behavior during repetitive muscle actions: a case report. BMC Research Notes 2014.

Zaheer et al. Preferred Sensor Sites for Surface EMG Signal Detection. Physiol Meas 2012.

McManus et al. Motor unit activity during fatiguing isometric muscle contraction in hemispheric stroke survivors. Front Human Neurosci 2017.

Dai C et al. Altered Motor Unit Discharge Coherence in Paretic Muscles of Stroke Survivors. Front Neurol 2017.

Hu et al. Altered motor unit discharge patterns in paretic muscles of stroke survivors assessed using surface electromyography. J Neural Eng 2016.

Richards & Selfe. EMG Decomposition of Vastus Medialis and Vastus Lateralis in normal subjects and patellofemoral patients: A new way of assessing the balance of muscle function? International Patellofemoral Research Retreat, 2011.