Targeting Rehabilitation Medicine
Posted in Sponsored Feature on 13th Mar 2013
The use of ultrasound needle guidance to accurately target injections is now widely-established for regional anaesthesia and analgesia, thanks to recent advances in the resolution and ease of use of hand-carried ultrasound instruments such as the SonoSite Edge® system. As these instruments become ever more accessible and familiar in the healthcare setting, clinicians are finding an increasing number of novel applications for ultrasound, both as a diagnostic tool and to aid in the treatment of patients. Rehabilitation medicine is one area which has seen growing interest in the use of ultrasound over the last few years, particularly for the treatment of spasticity, applying the needle guidance techniques developed for anaesthesia to alleviate symptoms and improve outcomes for patients with neurological injuries.
The march of progress
The use of botulinum toxin to relieve spasticity is nothing new, but the accuracy with which injections can be delivered has been vastly improved by the introduction of ultrasound needle guidance. Previously, clinicians would have to rely on palpation techniques, electromyography or nerve stimulation to try and identify the correct location for injection of the toxin; palpation and electromyography methods are highly inaccurate and do not account for anatomical variations between individuals, while nerve stimulation methods can be both uncomfortable for patients and time consuming to perform. In contrast, ultrasound is highly accurate – allowing you to visualise the position of the needle tip relative to the muscle and surrounding structures in real time – rapid, and less invasive, leading to more accurate injections and a far better, more comfortable patient experience.
Despite these obvious advantages, ultrasound has only really become viable for needle guidance applications since the advent of robust, portable and easy-to-operate ultrasound instruments. Launched in 1999, the SonoSite 180 was the first hand-carried, battery-operated ultrasound system that was designed for use outside of the radiology department, giving clinicians access to this powerful technique without the need for specialist sonography training or arduous patient transfers. This ease of use, combined with the affordability of modern hand-carried systems, led to the rapid and widespread adoption of ultrasound needle guidance by anaesthetists as a practical alternative to nerve stimulator techniques. Since this time, point-of-care ultrasound systems have become commonplace in virtually every hospital in Britain, with an ever increasing number of clinical specialties using multifunctional instruments for a diverse array of applications.
The rehabilitation revolution
The needle guidance techniques developed by anaesthetists are directly applicable to neurological rehabilitation therapies, allowing localised, accurate injection of botulinum toxin. Unlike nerve stimulator or anatomical methods, ultrasound needle guidance ensures accurate needle placement regardless of patient physiology. This greatly improves the success rate of procedures, and probably also the desired clinical effects in terms of both the degree and duration of relief offered to patients. It also provides access to deep muscle groups, such as the iliopsoas muscles, which are not possible to be injected without imaging. Ultrasound guided injections allow visualisation of these muscles, measuring the depth and avoidance of neighbouring delicate structures and vessels during the injection.
As well as improving the comfort of patients both during and after treatment, ultrasound is a useful tool to help patients to understand what their treatment involves, and what the likely outcome might be. Explanations illustrated by ultrasound images of the target area can help the patient to feel more involved in the decision-making process, giving them a more thorough understanding of the aim of the procedure, whether that is to improve motor function or simply to make them more comfortable.
The improved accuracy achieved by ultrasound needle guidance also offers the potential for new treatment strategies, such as the use of nerve blocks as an alternative to botulinum toxin. Highly localised injection of long-acting neurotoxins, such as phenol derivatives, could provide an alternative to direct injection of the muscle to treat spasticity. This technique provides effective relief for the patient, but the high toxicity of these agents demands even greater accuracy of needle placement, making ultrasound guidance essential.
In addition to guiding injections, ultrasound can be used as a diagnostic aid, offering better insight into the morphology and extent of damage within spastic muscles. For example, recent observations have shown that the degree of muscle contracture can be estimated from the degree of fibrous tissue within the muscle. This fibrous growth is more echogenic than normal, healthy muscle tissue, and so can easily be identified by ultrasound.
A sound future
The advent of robust, portable and easy-to-operate ultrasound instruments has been a significant breakthrough throughout the healthcare sector, allowing faster, better targeted treatment of patients than ever before. The intuitive design and clinically-focused features of multifunctional point-of-care instruments – such as SonoSite’s Advanced Needle Visualisation – have helped to expand the role of ultrasound in rehabilitation medicine, leading to more accurate and effective treatment of a wide range of neurological injuries. The accuracy offered by ultrasound guided techniques is vital to the continued development of rehabilitation therapies and, by moving this technology from the radiology department to the bedside, the clinic or even the patient’s own home, we are better able to provide the right care at the right time.