Hi,
Just wanted to share this resource I found; this text contains the most comprehensive and current information on tremor that I have seen. It covers frequencies, types, and making differential diagnoses.
Most importantly, it lists out several different drugs that have alleviated difficult to treat tremors; many of these drugs are new to me. It also points out that Propanolol is effective in treating PD tremor. Anyway, it might be helpful to make a copy of this page to discuss with your neuros.
Parkinson's Disease and Movement Disorders edited by J. Jankovic and E. Tolosa PAGE 289 (link goes to other page)
Chapter 24: Tremors: Differential Diagnosis, Pathophysiology, and Therapy