Positive giant potentials: an electromyographic investigation.
Positive giant potentials (PGPs) consist of a peculiar EMG activity which is observed mostly in the large lower limb muscles, and mainly in men, either during the insertion of the needle electrode or during muscle contraction. PGPs have a shape similar to that of positive sharp waves, but with a larger amplitude (up to 25 mV). Their firing rate may reach 200 c/s. PGPs probably have no diagnostic significance since they are frequently observed in healthy individuals. They correspond to an insertional activity and should be recognized as such because they may be mistaken for giant motor unit potentials and thus be the source of diagnostic errors. The mechanism involved in the genesis of PGPs remains a matter of speculation.
Pinelli
P
P
Fondazione Clinica del Lavoro, Centro Medico di Riabilitazione di Veruno, Italy.
Roth
G
G
Magistris
M R
MR
D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000294:innervation / Q000503:physiopathology*; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology*