title: Perfusion brain SPECT in assessing motor improvement after deep brain stimulation in Parkinson's disease.
abstract: BACKGROUND
  High-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) has become an established therapeutic approach for the management of patients with late-stage idiopathic Parkinson's disease (PD). The aim of the present study was to assess regional cerebral blood flow (rCBF) changes related to motor improvement.
  
  
  METHODS
  Twenty-one PD patients underwent two rCBF SPECT studies at rest, once preoperatively in the off-meds state and the other postoperatively (at 6 ± 2 months) in the off medication/on stimulation state. Patients were classified according to the UPDRS and H&Y scale. NeuroGam software was used to register, quantify, and compare two sequential brain SPECT studies of the same patient in order to investigate rCBF changes during STN stimulation in comparison with preoperative rCBF. The relationship between rCBF and UPDRS scores was used as a covariate of interest.
  
  
  RESULTS
  Twenty patients showed clinical improvement during the first months after surgery, resulting in a 44 % reduction of the UPDRS motor score. The administered mean daily levodopa dose significantly decreased from 850 ± 108 mg before surgery to 446 ± 188 mg during the off-meds state (p < 0.001, paired t test). At the 6-month postoperative assessment, we noticed rCBF increases in the pre-supplementary motor area (pre-SMA) and the premotor cortex (PMC) (mean rCBF increase = 10.2 %, p < 0.05), the dorsolateral prefrontal cortex and in associative and limbic territories of the frontal cortex (mean rCBF increase = 8.2 %, p > 0.05). A correlation was detected between the improvement in motor scores and the rCBF increase in the pre-SMA and PMC (r = 0.89, p < 0.001).
  
  
  CONCLUSIONS
  Our study suggests that STN stimulation leads to improvement in neural activity and rCBF increase in higher-order motor cortical areas.
authors: Nuclear Medicine Department, Patras University Hospital, Patras, Rion, 26500, Greece. a_pashali@yahoo.gr
authors: Anna
authors: A
authors: Paschali
authors: Constantinos
authors: C
authors: Constantoyannis
authors: Fevronia
authors: F
authors: Angelatou
authors: Pavlos
authors: P
authors: Vassilakos
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply*; D046690:Deep Brain Stimulation; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008032:Limbic System / Q000098:blood supply; D008297:Male; D009044:Motor Cortex / Q000098:blood supply; D009048:Motor Skills / Q000502:physiology*; D009460:Neurologic Examination; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D012039:Regional Blood Flow / Q000502:physiology*; D012984:Software; D020531:Subthalamic Nucleus / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome