Sensory tricks in cervical dystonia: perceptual dysbalance of parietal cortex modulates frontal motor programming

Ann Neurol. 2000 Mar;47(3):322-8.


Cervical dystonia is a disabling basal ganglia disorder characterized by an involuntary head deviation to one side. A typical but also mysterious feature is the impressive improvement of muscle spasms and involuntary head posture by application of a sensory facial stimulus (sensory trick). Here, we report the effect of a sensory trick on cortical activation patterns in 7 patients with cervical dystonia by using H2(15)O positron emission tomography. The application of the sensory trick stimulus, resulting in a near-neutral head position, led to an increased activation mainly of the superior and inferior parietal lobule (ipsilateral to the original head turn) and bilateral occipital cortex and to a decreased activity of the supplementary motor area and the primary sensorimotor cortex (contralateral to the head turn). We propose that a perceptual dysbalance induced by a sensory trick maneuver leads to a relative displacement of the egocentric midvertical reference to the opposite side and a decrease in motor cortex activity. This modulation of motor programming gives novel insights into the mechanisms involved in sensorimotor integration in movement disorders.

MeSH terms

  • Adult
  • Aged
  • Brain Mapping
  • Cervical Vertebrae
  • Dystonia / diagnostic imaging*
  • Dystonia / physiopathology
  • Female
  • Frontal Lobe / diagnostic imaging*
  • Frontal Lobe / physiopathology
  • Humans
  • Male
  • Middle Aged
  • Parietal Lobe / diagnostic imaging*
  • Parietal Lobe / physiopathology
  • Somatosensory Cortex / diagnostic imaging*
  • Somatosensory Cortex / physiopathology
  • Tomography, Emission-Computed