Video 1
Examples of Severe ET – Section 1: Kinetic Tremor. Patient 1: High-amplitude kinetic tremor is present in both arms, but even more so in the left arm, when this patient carries out the task of transferring water between drinking glasses. He frequently spills water. Patient 2: Severe right arm kinetic tremor nearly prevents this patient from being able to grasp a drinking glass. When he finally grasps the glass, water spills profusely. Patient 3: Severe right-hand tremor is apparent in this patient’s Archimedes spiral. Section 2: Postural Tremor. In both patients, severe postural tremor is present in both arms when the wing-beating position is assumed, but it is worse on the left side, reaching an amplitude of several centimeters. Some patients with ET may exhibit mild dystonic posturing in an arm that has had long-standing and severe tremor. Patient 2 develops some flexion of the right thumb, which may be dystonic. Section 3: Intention Tremor. Patient 1: High-amplitude intention tremor in the right arm is seen during the finger–nose–finger maneuver. Patient 2: Severe intention tremor in the left arm manifests during the finger–nose–finger maneuver.