Hedera P, Fang JY, Phibbs F et al.
Vanderbilt University, Nashville, USA.
Mov Disord 2009;24:2285–8.
Editor’s note: There is a long-running debate about a possible relationship between essential tremor (ET) and Parkinson’s disease (PD), with some studies indicating that ET is a risk factor for PD (
Ann Neurol 1994;35:717–23,
Parkinsonism Relat Disorder 2003;9:225–31,
Mov Disord 2007;22:1607–14,
Mov Disord 2008;23:993–7). Patients with long-standing ET who develop PD tend to develop the tremor-dominant form of the condition.