Selective impairment of hand mental rotation in patients with focal hand dystonia

Mirta Fiorio, Michele Tinazzi, Salvatore M. Aglioti

Research output: Contribution to journalArticlepeer-review


Mental rotation of body parts determines activation of cortical and subcortical systems involved in motor planning and execution, such as motor and premotor areas and basal ganglia. These structures are severely impaired in several movement disorders, including dystonia. Writer's cramp is the most common form of focal hand dystonia. This study investigates whether patients affected by writer's cramp present with difficulties in tasks involving mental rotation of body parts and whether any impairments are specific to the affected hand or generalized to other body parts. For this purpose we tested 15 patients with right writer's cramp (aged 21-68 years, 8 women) and 15 healthy control subjects (10 women, age and education matched). Stimuli consisted of realistic photographs of hands and feet presented on a computer monitor in different orientations with respect to the upright canonical orientation. In each trial, subjects gave a laterality judgement by reporting verbally whether the presented body part was left or right. Two main results of the study are, firstly, writer's cramp patients are slower than controls in mentally rotating hands [F (1, 28) = 5.4; P = 0.028] but not feet, and secondly, the pattern of response times to stimuli at various orientations suggests that the mental motor imagery of controls and patients reflects the type of processes and mechanisms called into play during actual execution of the same movements. In particular, increased difficulty in rotating right-sided stimuli at 120° and left-sided stimuli at 240° would suggest that mental rotation of body parts reflects the anatomical constraints of real hand movements. In conclusion, patients with writer's cramp presented mental rotation deficits specific to the hand. Importantly, deficits were present during mental rotation of both the right (affected) and the left (unaffected) hand, thus suggesting that the observed alterations may be independent and even exist prior to overt manifestations of dystonia.

Original languageEnglish
Pages (from-to)47-54
Number of pages8
Issue number1
Publication statusPublished - Jan 2006


  • Basal ganglia
  • Body schema
  • Focal hand dystonia
  • Hand
  • Mental rotation

ASJC Scopus subject areas

  • Neuroscience(all)


Dive into the research topics of 'Selective impairment of hand mental rotation in patients with focal hand dystonia'. Together they form a unique fingerprint.

Cite this