Effect of zonisamide on post-traumatic Holmes' tremor

Holmes' tremor is a rare symptom characterized by a complex combination of resting, postural and intention tremor. A 66-year-old right-handed man post-traumatically developed severe action tremor in his right hand, which had a component of the re-emergent type and predominantly involved proximal muscles. He also presented mild resting tremor in his right hand. As the response of levodopa/carbidopa and arotinolol was limited, he started zonisamide, which resulted in dramatic improvement. The Fahn-Tolosa-Marin Tremor Rating Scale motor score improved from 52 points to 24 points. In conclusion, zonisamide could be a therapeutic option for post-traumatic Holmes' tremor. Further prospective studies are required.