OBJECTIVES: To assess changes in electrical impedance myography (EIM) parameters in amyotrophic lateral sclerosis (ALS). METHODS: Ten patients with ALS and a cohort of normal subjects underwent EIM testing of tibialis anterior. Montages using voltage and current electrodes placed at a distance (far) and in close proximity (near) were compared. The EIM parameters, resistance (R), reactance (X), and phase (theta) in the patients with ALS, were compared with normal values. RESULTS: theta measured at 50 kHz using the near montage was most sensitive to the presence of ALS, with 9 of 10 patients with ALS having smaller theta values than the calculated lower limit of normal. theta using the far montage and X using both the near and far montages were also sensitive to disease, whereas R did not seem to be useful. CONCLUSION: EIM is sensitive to muscle abnormalities in ALS, with theta measured with near montages providing the best results.
OBJECTIVES: To assess changes in electrical impedance myography (EIM) parameters in amyotrophic lateral sclerosis (ALS). METHODS: Ten patients with ALS and a cohort of normal subjects underwent EIM testing of tibialis anterior. Montages using voltage and current electrodes placed at a distance (far) and in close proximity (near) were compared. The EIM parameters, resistance (R), reactance (X), and phase (theta) in the patients with ALS, were compared with normal values. RESULTS: theta measured at 50 kHz using the near montage was most sensitive to the presence of ALS, with 9 of 10 patients with ALS having smaller theta values than the calculated lower limit of normal. theta using the far montage and X using both the near and far montages were also sensitive to disease, whereas R did not seem to be useful. CONCLUSION: EIM is sensitive to muscle abnormalities in ALS, with theta measured with near montages providing the best results.
Authors: Stefan Schwartz; Tom R Geisbush; Aleksandar Mijailovic; Amy Pasternak; Basil T Darras; Seward B Rutkove Journal: Clin Neurophysiol Date: 2014-05-17 Impact factor: 3.708
Authors: Codrin Lungu; Andrew W Tarulli; Daniel Tarsy; Phillip Mongiovi; Veronique G Vanderhorst; Seward B Rutkove Journal: Clin Neurophysiol Date: 2010-10-12 Impact factor: 3.708