Clinical characteristics of essential voice tremor: A study of 34 cases
Essential voice tremor appears to affect more women than men. One third to one half of affected individuals have a family history of tremor. About one half of cases occur with upper extremity tremor no more severe than that seen in similarly aged normal individuals, contrary to what has been thought to date. Essential voice tremor is probably more common than is generally suspected, and many cases appear to be undiagnosed many years after onset or are misdiagnosed, most often as spasmodic dysphonia. The key feature is kinetic laryngeal tremor which usually extends beyond the larynx to involve the phonatory apparatus globally. Botulinum toxin may be helpful, but benefit is typically incomplete and not universal. Prolonged postinjection breathiness is the most common barrier to useful treatment.