Get access

Cerebellar involvement in timing accuracy of rhythmic finger movements in essential tremor

Authors

  • Laura Avanzino,

    1. Department of Neurosciences, Ophthalmology and Genetics and Istituto Nazionale di Neuroscienze, University of Genoa, Via De Toni 5, 16132 Genoa, Italy
    2. Department of Experimental Medicine, Section of Human Physiology and Istituto Nazionale di Neuroscienze, University of Genoa, Genoa, Italy
    Search for more papers by this author
  • Marco Bove,

    1. Department of Experimental Medicine, Section of Human Physiology and Istituto Nazionale di Neuroscienze, University of Genoa, Genoa, Italy
    Search for more papers by this author
  • Andrea Tacchino,

    1. Department of Experimental Medicine, Section of Human Physiology and Istituto Nazionale di Neuroscienze, University of Genoa, Genoa, Italy
    Search for more papers by this author
  • Piero Ruggeri,

    1. Department of Experimental Medicine, Section of Human Physiology and Istituto Nazionale di Neuroscienze, University of Genoa, Genoa, Italy
    Search for more papers by this author
  • Alessandro Giannini,

    1. Department of Neurosciences, Ophthalmology and Genetics and Istituto Nazionale di Neuroscienze, University of Genoa, Via De Toni 5, 16132 Genoa, Italy
    2. Department of Experimental Medicine, Section of Human Physiology and Istituto Nazionale di Neuroscienze, University of Genoa, Genoa, Italy
    Search for more papers by this author
  • Carlo Trompetto,

    1. Department of Neurosciences, Ophthalmology and Genetics and Istituto Nazionale di Neuroscienze, University of Genoa, Via De Toni 5, 16132 Genoa, Italy
    Search for more papers by this author
  • Giovanni Abbruzzese

    1. Department of Neurosciences, Ophthalmology and Genetics and Istituto Nazionale di Neuroscienze, University of Genoa, Via De Toni 5, 16132 Genoa, Italy
    Search for more papers by this author

Professor G. Abbruzzese, as above.
E-mail: giabbr@unige.it

Abstract

The cerebellum is involved in the generation of essential tremor (ET) and cerebellar timing function is altered in patients with ET showing an increased variability of rhythmic hand movements. Using a sensor-engineered glove, we evaluated motor behaviour during repetitive finger tapping movements in 15 patients with ET and in 11 age- and gender-matched normal subjects. In addition, we investigated whether, in patients with ET, an inhibitory repetitive transcranial magnetic stimulation (1 Hz-rTMS) over lateral cerebellum was able to change timing properties and motor behaviour. Patients with ET showed a longer touch duration (TD) and a lower inter tapping interval (ITI) than normal subjects. The temporal variability of the movement (coefficient of variation of ITI) was increased in patients with ET. Neither clinical rating scale or tremor measurements correlated with any parameter of motor performance in the ET group. 1 Hz-rTMS over ipsilateral lateral cerebellum transiently affected the performance of patients with ET, by reducing TD values and normalizing ITI values. After 1 Hz-rTMS, the coefficient of variation of ITI was restored to values similar to those of normal subjects. We postulate that the strategy to increase TD, probably adopted to allow a better perception of movement, can affect ITI and its variability. The results support the idea that the cerebellum plays a central role in the selection of motor strategy of rhythmic finger movements, particularly in terms of temporal organization of movement.

Ancillary