Physiological tremor analysis of patients with anti-myelin-associated glycoprotein associated neuropathy and tremor.
Tremor is often associated with anti-myelin-associated glycoprotein (anti-MAG) peripheral neuropathy (PN), but its physiology has never been accurately described. This study quantified the physiological characteristics of tremors in patients with anti-MAG demyelinating PN. Eighteen patients with tremor and PN with demyelinating features (ages 30-86, mean = 66.5 years) were evaluated for anti-MAG antibodies (positive considered > or = 1:3200) and for tremor amplitude, frequency, side-to-side relationships, and electromyographic (EMG) activation patterns. Thirteen patients had anti-MAG titers >1:3200 and 8 had both positive anti-MAG titers and tremors. Anti-MAG PN patients revealed tremors higher in amplitude, lower in frequency, with greater side-to-side amplitude ratios, greater amplitude variability, and more consistent cocontracting antagonist EMG patterns that do not attenuate with inertial loading. We conclude that anti-MAG PN tremor is not due only to exaggerated physiologic mechanisms but may reflect a distinctive form of neurogenic tremor.
Pedersen
S F
SF
Department of Neurology, College of Physicians and Surgeons of Columbia University, New York, New York, USA.
Pullman
S L
SL
Latov
N
N
Brannagan
T H
TH
D000328:Adult; D000368:Aged; D003711:Demyelinating Diseases / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018992:Myelin-Associated Glycoprotein / Q000502:physiology*; D014202:Tremor / Q000503:physiopathology*
D018992:Myelin-Associated Glycoprotein