Satellite potentials of motor unit action potentials in normal muscles: a new hypothesis for their origin

EMGLAB: An interactive EMG decomposition program

“…The ability in EMGLAB to inspect individual discharges and subtract out interfering activity lends itself to investigations of the physiological mechanisms underlying electrophysiological phenomena. For example, we have used this ability to study the origin of satellite potentials in normal muscle (Lateva and McGill, 1999) and the mutual blocking behavior of action potentials in doubly innervated muscle fibers (Lateva et al, 2002(Lateva et al, , 2003.…”

Electrophysiological evidence of doubly innervated branched muscle fibers in the human brachioradialis muscle

“…For each irregular MUAP, the latencies of the volatile components and the terminal wave were determined as in Lateva and McGill (1999;2001). First, the mean MUAP waveform was averaged from the unfiltered signal using the identified discharge times as triggers.…”

“…Satellite potentials (or late-latency components) are occasionally seen in other normal human muscles (Lang and Partanen, 1976;Stålberg et al, 1996;Finsterer and Mamoli, 1997). Although in diseased states satellite potentials can occur before or after the main MUAP component, regular satellite potentials in normal human muscles always occur after the terminal wave of the MUAP-the deflection that marks the extinguishment of the main action potential (AP) volley at the muscle/tendon junction (Lateva and McGill, 1999). This is consistent with their being produced by retrograde propagation in non-innervated muscle fibers that are in electrical continuity with innervated fibers at the muscle/tendon junction (Lateva and McGill, 1999).…”

“…Although in diseased states satellite potentials can occur before or after the main MUAP component, regular satellite potentials in normal human muscles always occur after the terminal wave of the MUAP-the deflection that marks the extinguishment of the main action potential (AP) volley at the muscle/tendon junction (Lateva and McGill, 1999). This is consistent with their being produced by retrograde propagation in non-innervated muscle fibers that are in electrical continuity with innervated fibers at the muscle/tendon junction (Lateva and McGill, 1999). Here we analyze the morphology and blocking behavior of MUAPs with irregular satellite potentials to determine their anatomical origin.…”

Overview of the Application of EMG Recording in the Diagnosis and Approach of Neurological Disorders

“…• Satellite potentials are observed in subacute processes and result from denervated muscle fibers that are reinervated by collateral sprouts from adjacent unmyelinated or thinly myelinated fibers in early reinnervation stage [15].…”