Differential effects of propranolol on head and upper limb tremor in patients with essential tremor and dystonia

Abstract

Propranolol is used as the first-line treatment in essential tremor and it has also been proposed as a treatment for tremor in dystonia. However, several issues remain uncertain. For example, it is still not clear whether propranolol exerts a beneficial effect on head tremor. Moreover, no studies have investigated whether the effect of propranolol on head and upper limb tremor in essential tremor differs from that in dystonia. We aimed to assess the effects of propranolol on tremor in different body parts in essential tremor and in patients with tremor and dystonia. Twenty-nine patients with head and upper limb tremor were enrolled in the study, 14 with essential tremor, and 15 with dystonia. Participants underwent a clinical and kinematic analysis of tremor in two sessions, i.e., without (baseline) and 'on therapy' with propranolol. We found that head tremor was more severe in patients with dystonia, while upper limb tremor was more evident in patients with essential tremor (P < 0.05). Propranolol had no effect on head tremor in either group (all Ps > 0.05), but it did reduce upper limb tremor in patients with essential tremor. The present study demonstrates differential effects of propranolol on head and upper limb tremor in patients with essential tremor. The lack of effect on head and upper limb tremor in patients with dystonia suggests that the pathophysiological mechanisms underlying tremor in these two conditions and in different body parts may be distinct.

Clinical and Kinematic Features of Valproate-Induced Tremor and Differences with Essential Tremor

“…Kinematic recordings were performed using an optoelectronic system (SMART motion system, BTS Engineering, Italy) consisting of three infrared cameras (sampling rate of 120 Hz) and reflective markers of negligible weight taped to the subject's arms, trunk and head [15][16][17]. For the upper limbs, we used four markers placed on the distal phalange of the index finger and on the second metacarpal bone of each hand.…”

“…In the present study, we aimed to better characterise clinical and kinematic features of VIT using standardized clinical scales and an objective assessment of tremor through motion analysis [15][16][17]. To this aim, we investigated postural, kinetic and rest tremor in different body parts, including the upper limbs and head [15][16][17]. We investigated possible correlations between demographic, clinical and kinematic data in VIT patients.…”

Essential tremor: diagnosis and management

“…The table highlights the small sample size, short periods of assessment, and variability or lack of definition of essential tremor stated in the studies. Head tremor and voice tremor do not objectively respond to chronic propranolol therapy 114115…”

Treatment of essential tremor: current status

“…A combination of these two drugs yields a better response compared with using either of them alone 8 9. Both these drugs have shown efficacy in reducing tremor amplitude up to 1 year of treatment 10–17. However, there are no RCTs done to assess the long-term effects of either propranolol or primidone in ET 17.…”