Bradykinesia of posed smiling and voluntary movement of the lower face in Parkinson's disease

Luca Marsili, Rocco Agostino, Matteo Bologna, Daniele Belvisi, Adalgisa Palma, Giovanni Fabbrini, Alfredo Berardelli

Research output: Contribution to journalArticlepeer-review


Objective: Impaired facial expression, including spontaneous and emotional movements such as smiling, has been often reported in Parkinson's disease (PD). There is a general consensus that spontaneous smiling is abnormal in PD. Investigations on posed smiling yield contrasting results. Moreover, no study has yet addressed the relationship between posed smiling and abnormalities of voluntary movements of the lower face, global motor impairment and the effects of dopaminergic medication. Methods: We investigated the kinematics of posed smiling (mimicking a smile shown in a picture) and those of voluntary movements of the lower face (showing the teeth as fast as possible - voluntary grinning) in 15 patients with PD (ON and OFF therapy) and in 16 healthy controls. Facial movements were recorded using a 3D optoelectronic system and analyzed using dedicated software. Results: Some kinematic parameters of both posed smiling and voluntary grinning were abnormally lower in PD patients in comparison to healthy subjects. The kinematics of posed smiling correlated with those of voluntary grinning in PD patients but not in healthy controls. Posed smiling and voluntary grinning abnormalities were related to global motor severity but did not significantly improve upon L-dopa administration. Conclusions: These results suggest that posed smiling and voluntary grinning are both abnormal in PD patients and that they are likely mediated by a common pathophysiological mechanism.

Original languageEnglish
Pages (from-to)370-375
Number of pages6
JournalParkinsonism and Related Disorders
Issue number4
Publication statusPublished - 2014


  • Bradykinesia
  • Motor control
  • Neurophysiology
  • Parkinson's disease

ASJC Scopus subject areas

  • Geriatrics and Gerontology
  • Clinical Neurology
  • Neurology
  • Medicine(all)


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