Tremor in Multiple Sclerosis as Measured Using the NARCOMS Tremor and Coordination Scale
Ruth Ann Marrie, MD, PhD
Departments of Internal Medicine and Community
Tremor is an abnormal, involuntary movement of the body that may affect hands, arms, trunk, head, legs, or voice. It is a symptom frequently experienced by Multiple Sclerosis patients. Resting tremors are most noticeable when the muscle is relaxed, for example, when the hand is resting on the lap.
Action tremors occur when the affected body part, such as the arm, moves or is held in a specific position. Task-specific tremors only occur when very specific tasks, such as handwriting, are involved.
Some studies report that 25–58% of persons with MS have experienced tremor.1,2 However, less than 15% of persons with MS present with tremor or poor balance as the first symptom.3 In one study examining 100 persons with MS attending an MS clinic, 58 had tremor. Action tremor affected most often the arms (56%), followed by the legs (10%), the head (9%), and the trunk (7%).1 None of the tremors occurred at rest.
There are multiple ways of measuring tremor. First, persons with tremor can do standardized performance tests, such as the Nine Hole Peg Test (9HPT). 4, 5 In this simple test of arm coordination, the participant is timed placing nine pegs into nine holes, then removing each peg.
The test is usually done twice with each hand. Second, rating scales that describe the location and severity of the tremor can be used. Functional tests observe the impact of tremor on typical daily tasks, such as drinking from a full glass.6–8 Finally, some questionnaires assess the effect of tremor on daily activities from the patient’s perspective.4
Several years ago, NARCOMS developed a single question in its survey, called the Tremor and Coordination Scale (TACS), to assess the impact of tremor and impaired coordination on daily activities. In this study we compared the TACS to a standardized performance test, and looked at how often persons with MS report moderate or severe problems due to tremor.9
The participants in this study also underwent a neurological examination, and completed the Multiple Sclerosis Functional Composite (MSFC) test battery. One of the three parts of the MSFC is the Nine Hole Peg Test (9HPT) described earlier. The participants also filled out the NARCOMS TACS and Performance Scales as NARCOMS participants typically do.