Ultrasound-Guided Botulinum for Spasticity and Applications in Physiatry

Todd Beery

Physiatrists have recognized the clinical use of ultrasound for several decades. The use and relevance of ultrasound in the field is demonstrated by a group of physiatrists establishing the AmErican Institute for Ultrasound in Medicine.¹ The use of ultrasound has expanded with improved technology and resolution. These improvements have led to the implementation of ultrasound in the detection of musculoskeletal and neuromuscular pathology along with guidance for therapeutic procedures.²

The objective of this chapter is to briefly review some of the advantages and disadvantages of ultrasound compared to other imaging modalities and present the clinical applications of ultrasound in the field of physiatry.

Ultrasound is an appealing modality for its convenience, noninvasiveness, and portability. It is relatively inexpensive compared to computed topography and magnetic resonance imaging (MRI). In contrast to conventional radiography, ultrasound does not expose patients to radiation. Ultrasound has no known contraindications and results in minimal artifact from metallic objects.³

There are several limitations to ultrasound as an imaging modality. The imaging window of ultrasound is relatively small. It provides detailed soft-tissue imaging of a focal area; however, it can be tedious and difficult to evaluate a widespread anatomical area. In addition, ultrasound has limited resolution at greater depths, making visualization of obese patients more challenging. Ultrasound lacks the ability to penetrate bone, which can prevent views of deep body regions or central intra-articular regions.⁴ Lastly, the use of ultrasound is operatordependent and can be technically demanding. It requires skill and experience along with a solid knowledge base of anatomy.

What are some clinical indications for ultrasound in physiatry?

A diagnosis of musculoskeletal pathology
Interventional procedure guidance
A diagnosis and treatment of residual limb pain in amputees
To aid in the diagnosis of entrapment neuropathies and complement nerve conduction studies and electromyography
To assist in the treatment of targeted spasticity management in central nervous system pathology

A diagnosis of musculoskeletal pathology

Ultrasound can serve as an initial imaging modality for several musculoskeletal conditions. It can be performed quickly and conveniently in the office setting. It is well tolerated by patients, and it can be a useful tool in efficiently assessing musculoskeletal conditions. Its use in the outpatient clinic has been associated with a decreased need for office visits, improved clinical outcomes, and increased patient satisfaction.⁵

Musculoskeletal ultrasound offers unique aspects that are absent in other imaging modalities. A comparison of static and dynamic evaluations can be performed. Real-time imaging can be observed during provocative physical exam maneuvers. Ultrasound offers the ability for sonopalpation of painful locations. The precise localization of the area of maximal tenderness can be identified and visualized by palpating under the transducer. A contralateral comparative exam of extremities can easily be performed if indicated. The use of these techniques can aid in the diagnosis of muscle, tendon, ligament, and nerve pathologies.⁶

Interventional procedure guidance

Ultrasound has become an invaluable tool for interventional procedures. It facilitates direct visualization of the needle trajectory and final placement. There are a wide variety of interventional procedures that encompass the use of ultrasound. These include therapeutic injections to joints, bursa, tendons, nerve sheaths, and muscles.⁷ The specifics of injections techniques are discussed in other chapters. There is evidence that ultrasound results in more accurate needle placement when compared to anatomical landmarks for a variety of injection sites.⁸^, ⁹^, ¹⁰^, ¹¹^, ¹²^and ¹³ However, there is not convincing evidence that ultrasound guidance translates into improved clinical efficacy.¹⁴^, ¹⁵^and ¹⁶

A diagnosis and treatment of residual limb pain in amputees

Residual limb pain in amputees can be debilitating. The etiology of the pain generator is vast and can be difficult to diagnose. Ultrasound can effectively assess the potential causes of residual limb pain. Fluid collections from adventitious bursae or neuromas can be identified with ultrasound.¹⁷

Only gold members can continue reading. Log In or Register to continue