Hi, my name is Dr. Mary Russell, and I am Assistant Professor and Vice Chair at the University of Texas McGovern Medical School at Houston. I am also Medical Director at Tier Memorial Hermann in the Woodlands and have an outpatient spasticity practice. I'm here to talk to you today about guidance techniques for interventional spasticity management. I am on the Speakers Bureau for Xeomin with MERS and on the Speakers Bureau for Botox with Allergan. Learning objectives for today include to be familiar with different guidance techniques for interventional spasticity management, understand the benefits and limitations for electrical stimulation, understand the benefits and limitations for electromyography, and understand the benefits and limitations for ultrasound. The goals of guidance techniques are to increase accuracy of injections into target muscles and reduce the risk of injection into nerves, veins, arteries, and adjacent structures next to the target muscle. There are different types of guidance for interventional spasticity management. There's anatomic guidance, which includes surface anatomy and bony landmarks. There's electromyography, or EMG, and there's electrical stimulation, or eSTIM, as well as ultrasound. Anatomic guidance for interventional spasticity management includes palpation, anatomic landmarks, and surface anatomy, as well as passive and active range of motion. The benefits to this type of guidance is that it is low-cost and quick, however, it does have several limitations. In a study by Boone et al. in 2011, there was 39% blind accuracy versus 96% with ultrasound accuracy for the same muscles using anatomic landmarks. And this was even in experienced injectors. An article by Schnitzler in 2012 found that there was 43% accuracy using surface palpation only of the gastrocnemius. Electromyography has several benefits. It can give auditory and or visual feedback, it demonstrates active motor unit potentials or insertional activity, and also shows improved accuracy. However, it is more costly than anatomic guidance. It's more time-consuming, and there can also be confounding principles such as co-contraction impaired relaxation that may confound the signal. Electrical stimulation, or eSTIM, is another guidance technique. It can demonstrate visible muscle contraction in the target muscle. It's relatively inexpensive and also demonstrates improved accuracy. It's definitely useful when co-contraction limits isolation of target muscles, such as with EMG. It does have several limitations. It is more costly than anatomic guidance. It is more time-consuming and can be painful or uncomfortable to the patient. Volume conduction can also cause contraction outside of the target muscle. Ultrasound has several benefits. It also demonstrates improved accuracy. It's able to visualize nerves, veins, arteries, and organs. You're able to visualize injection within the target muscle, and it's also useful in non-muscle tissue, such as glands. It does tend to be more costly than other guidance techniques and more time-consuming. You can use a combination of guidance techniques for interventional spasticity management. This can include EMG and ultrasound, which is excellent for cervical dystonia. It can precisely locate the target and provide info on muscle activity. It's also useful for placement in muscle targets. eSTIM and ultrasound is excellent for motor point and nerve blocks using phenol or alcohol. It precisely locates target muscles and is useful for muscle or nerve targets. It's been shown by Matsumoto in 2018 that there was a lower dose of phenol needed to achieve the same effect in elbow flexor spasticity when the combination of eSTIM and ultrasound was used. So electromyography, or EMG, can be used as stationary units, such as you would use for an electromyography and nerve conduction study or a handheld unit, such as shown in the pictures to the left. Electrical stimulation similarly can be stationary units or handheld units. Ultrasound additionally has larger units and more portable units that can be used. With EMG, you need to place a reference electrode over bone near the injection site to get the best signal. Your injection needle serves as your active electrode. With electrical stimulation, you also place a reference electrode somewhere on the body. Your injection needle also serves as your active electrode. With ultrasound, you have the option for in-plane and out-of-plane injections and can also use the Doppler feature to isolate vessels. Knowledge of the following is not a use of electrical stimulation for guidance in spasticity management. A, isolation of target muscles, B, isolation of motor point blocks, C, isolation of glands for cialorrhea, or D, isolation of nerves for neuralysis. The correct answer is C. Electrical stimulation is a useful tool for isolation of target muscles when co-contraction is a concern. It is also useful for motor point blocks and isolation of nerves with neuralysis. Electrical stimulation does not assist with the isolation of glands, such as that treated for cialorrhea. There are several methods for localization of target structures in interventional spasticity management, anatomical, electromyography, electrical stimulation, and ultrasound. Combination techniques are most sensitive for localization and can be useful to your spasticity practice.

interventional spasticity management

guidance techniques

electromyography

ultrasound

combination techniques