Differentiating Essential and Dystonic Head Tremor: Exploring Arm Position Effects.

Background: Head tremor poses diagnostic problems, especially when present as an isolated or predominant symptom.

Objectives: To assess how maneuvers activating upper limb postural tremor can help differentiate head tremor in essential tremor (ET) from dystonic tremor (DT) in cervical dystonia.

Methods: 48 patients with head tremor (25 ET, 23 DT), underwent clinical examination and accelerometric evaluation of head and upper limb tremor during routine tremor-inducing tasks.

Results: While accelerometric power and clinical scores of head tremor did not significantly differ between patient groups, task-induced variations revealed distinctions. ET patients exhibited increased head tremor power and clinical scores during forward outstretched and lateral wing-beating arm positions, unlike DT patients. Coherence between head and upper limb tremor remained consistent. Tremor stability index showed no significant differences.

Conclusions: Task-induced changes in head tremor could aid in distinguishing between ET and DT. Further research is needed to refine diagnostic approaches for head tremor.