DAT SPECT and Procedural Motor Skills in Parkinson's Disease
DAT SPECT and Procedural Motor Skills in Parkinson's Disease
Patients with Parkinson's disease (PD) are known to be affected by subtle cognitive
 impairment early in the disease course, mostly in the executive field. Procedural motor
 skills, mainly controlled by the basal ganglia associative loop (in particular dorsal caudate
 nucleus) (Rodriguez-Oroz et al., 2009), have also been studied in patients with PD (Schnider
 et al., 1995; Muslimovic et al., 2007; Terpening et al., 2013). However, the correlation of
 dopaminergic 123I-FP-CIT SPECT imaging and cognitive impairment has not been assessed. One
 reason is the absence of reference values for striatal uptake until recently. Last year, the
 investigators established local uptake reference values for DAT imaging based on a large
 cohort of subjects with non-degenerative conditions (Nicastro et al., 2016) and can therefore
 use these values to precisely assess uptake loss in patients with PD.

 With the present study, the investigators expect to enroll patients with early PD for whom a
 123I-FP-CIT SPECT has been previously performed in the center. Subjects will perform a
 specific motor task based on mirror-drawing of star-shaped figures. This will be done by
 inverting the direction of horizontal/vertical computer mouse movements on the screen. Speed
 and error rates will be assessed for patients as well as healthy control subjects.
 Correlation with striatal SPECT uptake, especially caudate nucleus uptake, will be analyzed
 for PD patients. In addition, resting-state EEG will be performed for all subjects. General
 medication and dopaminergic drugs in particular, whenever used, will not be discontinued. For
 all subjects enrolled in the study, cognitive and neurological examination will be performed.
Inclusion criteria for PD group:

 -  Age > 18 year-old

 -  Diagnosis of PD with onset <2 years from enrollment

 -  Available DAT SPECT performed in Geneva University Hospitals <6 months before
 inclusion

 Inclusion criteria for control group:

 Age- and sex-matched control patients

 -  Age > 18 year-old

 -  No known neurological condition interfering with motor and cognitive abilities

 -  No medication interfering with central nervous system (including antidepressants,
 antipsychotics, hypnotics)

 Exclusion criteria for both groups:

 -  Major depressive state (Hospital Anxiety and Depression scale ≥11 for depression
 score)

 -  Cognitive decline (Mini-Mental Score ≤ 22/30)

 -  Debilitating tremor (Movement Disorders Society - Unified Parkinson's Disease Rating
 Scale (MDS-UPDRS) part III - rest, postural and action tremor ≥2/4)

 -  Significant akinesia (MDS-UPDRS III hand brady-akinesia score ≥2/4)