Tremor in reflex sympathetic dystrophy
G. Deuschl, H. Blumberg and C. H. Lucking
Department of Neurology, University of Freiburg Breisgau, Germany.
Postural hand tremor was quantitatively investigated on both sides in 21
patients suffering from unilateral reflex sympathetic dystrophy of the
upper extremity. On the affected side, enhanced tremor amplitude, with a
mean tremor frequency of 7.2 Hz, was found in 57% of the patients. The
appearance of tremor did not correlate to the occurrence of a single
clinical symptom of reflex sympathetic dystrophy. On loading with
increasing weight, the frequency of this pathological tremor shifted toward
lower values, as it is found in physiological tremor. However, the peak
frequencies of the electromyogram remained more or less stable. On recovery
from this condition, the reflex sympathetic dystrophy tremor disappeared.
Acute sympatholytic intervention could normalize reflex sympathetic
dystrophy tremor. This would suggest that the sympathetic supply of the
affected extremity contributes to the tremor in reflex sympathetic
dystrophy. In conclusion, it is suggested that reflex sympathetic dystrophy
should be included among the causes of tremor. According to our findings,
tremor in reflex sympathetic dystrophy should be regarded as an enhanced
physiological tremor.
