title: Intention Tremor of the Legs in Essential Tremor: Prevalence and Clinical Correlates.
abstract: OBJECTIVE
  To estimate the prevalence and assess the clinical correlates of intention tremor in the legs in essential tremor (ET) patients.
  
  
  BACKGROUND
  The cerebellar features of ET are of growing interest to clinical neurologists. Arm tremor has an intentional component in many ET patients. Intention tremor in the legs, however, has never been systematically evaluated.
  
  
  METHODS
  One-hundred-twenty-eight ET patients were enrolled in a clinical-epidemiological study at Columbia University. A videotaped neurological examination included 10 toe-to-target movements with each foot. Videotapes were independently reviewed by two movement disorder neurologists who noted the presence vs. absence of intentional leg tremor. Two patients underwent quantitative computerized tremor analysis to study the physiological characteristics of the tremor.
  
  
  RESULTS
  Thirty-five patients (27.3%) had intentional leg tremor; in 21, tremor was unilateral and in 14 it was bilateral. The 35 patients with intentional leg tremor did not differ from the remaining 93 patients in their clinical characteristics. Analyses comparing the 14 patients with bilateral intentional leg tremor to the 93 patients with no intentional leg tremor showed trends towards longer disease duration and more severe intentional arm tremor in the former. Tremor analysis showed a 3-fold increase in average tremor amplitude from movement onset to the point just prior to touching the target.
  
  
  CONCLUSIONS
  Our data suggest that intentional leg tremor, another cerebellar feature, is common in ET patients. The tremor may be associated with longer disease duration and more severe intentional arm tremor, but these preliminary trends need to be assessed in larger study samples.
authors.affiliation: Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA.
authors.forename: Meir
authors.initials: M
authors.lastname: Kestenbaum
authors.affiliation: GH Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, New York, USA.
authors.forename: Monika
authors.initials: M
authors.lastname: Michalec
authors.affiliation: Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA.
authors.forename: Qiping
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA.
authors.forename: Seth L
authors.initials: SL
authors.lastname: Pullman
authors.affiliation: Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA ; GH Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, New York, USA ; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, New York, USA ; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York, USA.
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
keywords: Essential tremor; cerebellum; clinical; intention tremor