Described herein are embodiments of methods and apparatus for diagnosing neuromuscular diseases using an impedance-EMG needle, and for generating electrical impedance images using an impedance needle. Some embodiments provide an apparatus including an impedance-EMG needle, including both EMG electrodes and impedance electrodes, to measure both active and passive electrical properties of muscle. Other embodiments provide an apparatus including an impedance needle, including a plurality of impedance electrodes to measure impedance in tissue surrounding the impedance needle to generate an electrical impedance image. Use of such methods and apparatus may be advantageous in improving the accuracy of assessing and diagnosing neuromuscular disease.