Primary writing tremor is a tremor which occurs only (or predominantly) during writing but not during other tasks in the active hand( Deuschl G et al, 2010). It is mainly a pronation-supination tremor with a frequency of 5-6 Hz. The cardinal feature is the limited range of action during which the tremor is present. It can be task induced (Type-A) or position induced (Type-B). Due to its rarity, the epidemiology and the causes are unknown, but mostly it is idiopathic (Bain PG, et al 1995).
Various drugs including propranolol, primidone, levodopa, and neuroleptics have been tried with variable results. Botulinum toxin has been reported to be useful. Overall primary writing tremor is difficult to treat symptoms and even surgical methods such as selective thalamotomy and DBS have been tried with success ( Deuschl G et al, 2010; Racette BA, et al 2001).