title: Differences in muscle strength in parkinsonian patients affected on the right and left side.
abstract: BACKGROUND
  Muscular weakness is a frequent cause of instability that contributes to falls in Parkinson's disease (PD). Isokinetic dynamometry is a method of muscle assessment useful to measure the muscular strength giving a quantification of the weakness, but only few studies about isokinetic assessment were performed in PD. The aims of the study were to evaluate the muscle strength in PD and to investigate the differences in patients affected on the right and left side.
  
  
  METHODS
  Knee flexor and extensor muscles strength was assessed using an isokinetic dynamometer in 25 patients in stage 3 H&Y and in 15 healthy controls. Subjects were tested in both legs at three fixed angular velocities: 90°/s, 120°/s, 180°/s.
  
  
  RESULTS
  Considering the whole population of Parkinsonians, no difference in strength was observed with respect to controls. Considering the side, patients affected on the right side showed a clear tendency to be weaker than patients affected on the left side and controls.
  
  
  CONCLUSIONS
  PD patients affected on the right side, but not those affected on the left side, had a reduction in muscle strength as compared to controls. We postulate a central origin deficit in muscle strength in PD. It is known that dopamine transporter binding is more severely reduced in the left posterior putamen and our results suggest that the control of the muscle strength in PD is linked to the right-left hemispheric asymmetry of the functional organization of basal ganglia and with their connections to cortical motor and pre-motor areas.
authors: Department of Parkinson Disease and Brain Injury Rehabilitation, "Moriggia-Pelascini" Hospital, Gravedona ed Uniti, Italy; Fondazione Europea Ricerca Biomedica (FERB), "S.Isidoro" Hospital, Trescore Balneario, Italy.
authors: Giuseppe
authors: G
authors: Frazzitta
authors: Department of Parkinson Disease and Brain Injury Rehabilitation, "Moriggia-Pelascini" Hospital, Gravedona ed Uniti, Italy.
authors: Davide
authors: D
authors: Ferrazzoli
authors: Department of Biomedical Engineering, Scientific Institute of Montescano, S. Maugeri Foundation, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Montescano, Italy.
authors: Roberto
authors: R
authors: Maestri
authors: Department of Neurorehabilitation, Scientific Institute of Montescano, S. Maugeri Foundation, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Montescano, Italy.
authors: Roberta
authors: R
authors: Rovescala
authors: Department of Neurorehabilitation, Scientific Institute of Montescano, S. Maugeri Foundation, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Montescano, Italy.
authors: Gabriele
authors: G
authors: Guaglio
authors: Department of Parkinson Disease and Brain Injury Rehabilitation, "Moriggia-Pelascini" Hospital, Gravedona ed Uniti, Italy.
authors: Rossana
authors: R
authors: Bera
authors: Department of Physical Medicine and Rehabilitation, "S. Raffaele Arcangelo Fatebenefratelli" Hospital, Venezia, Italy.
authors: Daniele
authors: D
authors: Volpe
authors: Parkinson Institute, Istituti Clinici di Perfezionamento, Milano, Italy.
authors: Gianni
authors: G
authors: Pezzoli
mesh_terms: D000368:Aged; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007717:Knee / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D018908:Muscle Weakness / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010300:Parkinson Disease / Q000503:physiopathology*; D019415:Torque