Spasticity

Diagnosis and Assessment

A key point in the assessment of spasticity is to standardize the environment, i.e., to perform the patient's assessment at the same time of day and in the same manner, at each visit. Exacerbating factors, such as urinary tract and other infections, pressure sores, ingrown toenails, and constipation, should be accounted for and removed to the extent possible before performing the assessment. Observing the person with spasticity perform activities such as walking, drinking from an open cup, and moving from one position to another often yields valuable information. In this manner, the assessment should examine the extent to which spasticity is limiting function—

• The amount of spasticity in each limb
• The impact of changing spasticity on function
• The degree of weakness
• The impact of weakness on function

A standard evaluation of the nervous system forms the first step of the clinical examination, including an assessment of both strength and reflexes. Next, with the patient fully relaxed, each joint is moved through its full range of motion at various speeds. When stretching a limb affected with spasticity, the examiner will feel a "catch,"—a sudden increase in resistance to the stretch. Note should be made of the point at which the catch occurs and the speed with which the joint is moved when the catch occurs. Performing the range of motion may also elicit the "clasped-knife" phenomenon. Clasped knife occurs when the spastic muscle is stretched—the resistance to stretch is initially marked but then suddenly relents.16

A variety of scales have been developed to standardize the recording of these findings from the clinical examination of spasticity. The most often used are the Modified Ashworth Scale, and the Tardieu Scale.17,18 Other scales are used less frequently, primarily for research purposes. The 6 points of the Modified Ashworth Scale (which includes a 1+ rating) correlate with clinician-determined increasing levels of spasticity during passive range of motion, from no change in or diminished muscle tone (0) to complete inability to move the joint (5). In addition to the degree of spasticity, the Tardieu Scale also includes the angle and velocity of the movement that elicits the response.

Because one of the primary reasons to treat spasticity is its effect on function, the ability to measure change in function is important. Formal measures, such as the Fugl-Meyer Scale,19 have been developed to measure functioning in patients with spasticity. However, these tools may not be sensitive to changes in spasticity per se and are infrequently used outside of the research setting. Therefore, the clinical assessment becomes more important and is likely to focus on patients' ability to complete a task, the quality of their completion of the task (e.g., ease of movement, normalization of gait), and the length of time that it takes them to complete the task. The clinical assessment should also include and evaluations of the change in level of pain, ease of caregiving or hygiene, or overall quality of life.