OBJECTIVE: To determine the feasibility of performing electrical impedance myography (EIM) in rats. METHODS: EIM was performed on the hamstring muscles of 6 healthy adult rats with applied frequencies of 2-300 kHz. Studies were performed over a 6-week period, with 3 rats having recordings made from the skin (surface EIM) and 3 with recordings directly from the muscle (direct-muscle EIM). In addition, sciatic nerve crush was performed on one rat and comparisons made pre- and post-injury. Reactance and resistance were measured and the primary outcome variable, the phase angle (theta), calculated. RESULTS: EIM patterns in the rat hamstring muscles were qualitatively similar to those observed in human subjects. This held true for both surface and direct-muscle recordings, although direct-muscle data appeared less repeatable. Sciatic nerve crush data in the single rat showed a dramatic reduction in phase and a relative loss of frequency-dependence. CONCLUSIONS: EIM data similar to that obtained from human subjects can be acquired from rat muscles with surface recordings proving more consistent and easier to obtain than direct-muscle recordings. Changes seen with sciatic nerve crush mirror those seen in patients with neurogenic injury. SIGNIFICANCE: These results support the possibility of performing EIM on rat models of neuromuscular disease.
OBJECTIVE: To determine the feasibility of performing electrical impedance myography (EIM) in rats. METHODS: EIM was performed on the hamstring muscles of 6 healthy adult rats with applied frequencies of 2-300 kHz. Studies were performed over a 6-week period, with 3 rats having recordings made from the skin (surface EIM) and 3 with recordings directly from the muscle (direct-muscle EIM). In addition, sciatic nerve crush was performed on one rat and comparisons made pre- and post-injury. Reactance and resistance were measured and the primary outcome variable, the phase angle (theta), calculated. RESULTS: EIM patterns in the rat hamstring muscles were qualitatively similar to those observed in human subjects. This held true for both surface and direct-muscle recordings, although direct-muscle data appeared less repeatable. Sciatic nerve crush data in the single rat showed a dramatic reduction in phase and a relative loss of frequency-dependence. CONCLUSIONS: EIM data similar to that obtained from human subjects can be acquired from rat muscles with surface recordings proving more consistent and easier to obtain than direct-muscle recordings. Changes seen with sciatic nerve crush mirror those seen in patients with neurogenic injury. SIGNIFICANCE: These results support the possibility of performing EIM on rat models of neuromuscular disease.
Authors: Seward B Rutkove; Hui Zhang; David A Schoenfeld; Elizabeth M Raynor; Jeremy M Shefner; Merit E Cudkowicz; Anne B Chin; Ronald Aaron; Carl A Shiffman Journal: Clin Neurophysiol Date: 2007-09-25 Impact factor: 3.708
Authors: Benjamin Sanchez; Shama R Iyer; Jia Li; Kush Kapur; Su Xu; Seward B Rutkove; Richard M Lovering Journal: Muscle Nerve Date: 2017-03-24 Impact factor: 3.217
Authors: Mohammad A Ahad; P Michelle Fogerson; Glenn D Rosen; Pushpa Narayanaswami; Seward B Rutkove Journal: Physiol Meas Date: 2009-11-04 Impact factor: 2.833