October 16, 2002
By Ed Susman
Special to DG News
NEW YORK, NY
Patients with multiple sclerosis (MS) can achieve relief from fatigued-induced tremor if they use glatiramer acetate, researchers reported here October 15 at the 127th annual meeting of the American Neurological Association (ANA).
"Tremor and fatigue are the most common movement disorders found in multiple sclerosis patients," said Selim Dogan, PhD, a research specialist in the department of neurology at University of Wisconsin, in Madison, Wisconsin, United States.
Tremor and fatigue in MS patients are caused by pathological changes, but little research has been done looking at how fatigue affects tremor, the researchers noted.
Dr. Dogan and colleagues studied patients with MS with tremor -- 73 treated with glatiramer acetate and 65 non-treated patients. Patients underwent a standard computerized tremor assessment before and after performing fatigue-inducing tasks.
Each patient underwent a standard computerised tremor assessment before and after 30 to 40 seconds of a fatigue task. A uniaxial accelerometer recorded hand tremors for each patient. The amplitude and frequency of bilateral hand postural tremor was determined using standard algorithms on the uniaxial accelerometer data.
No difference was seen between pre-task tremor and post-task tremor among those patients receiving glatiramer acetate, but tremor amplitude increased significantly among the patients who did not receive the drug.
The amplitude of postural tremor worsened 4- to 8-fold in some patients after fatigue task, with a baseline gravitational acceleration average of 0.0107 versus a post-task average of 0.0132 in treated patients compared to non-treated patients, who had a baseline average of 0.0241 and post-task average of 0.0725.
Using paired t test statistical analysis the researchers found a statistically significant difference between pre-task and post-task tremor in the two groups, which indicated that postural tremor amplitude worsened significantly in non-treated patients (p=0.0196) after the fatigue task. On the other hand, there was no statistically significant difference between pre-fatigue and post-fatigue tremor in treated patients (p=0.132) after 30 to 40 seconds of the fatigue task.
"Glatiramer acetate treatment is associated with amelioration of the post-fatigue-induced increase in postural amplitude seen after 30 to 40 seconds of sustained posture in MS patients," Dr. Dogan concluded. "Tremor and fatigue interfere with activities of daily living and tremor becomes incapacitating with fatigue inducing daily tasks."
The researchers suggested that studying the computerized tremor assessment may help clinicians idnetify various types of tremors in MS patients and also allow clinicians to assess efficacy of treatment.
The study was supported by funding from the University of Wisconsin
and the US Department of Veterans Affairs.
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