Chronic motor cortex stimulation in patients with advanced Parkinson's disease and effects on striatal dopaminergic transmission as assessed by 123I-FP-CIT SPECT:  a preliminary report.
OBJECTIVE
The objective of this study was to assess striatal dopamine transporter availability in patients with advanced Parkinson's disease (PD) before and after 13 months of unilateral extradural motor cortex stimulation (EMCS) with [123I]N-ω-fluoropropyl-2-β-carbo-methoxy-3-β-(4-iodophenyl)nortropane single photon emission computed tomography (123I-FP-CIT SPECT).


METHODS
Six PD patients (five women and one man, aged 63.2 ± 5.6 years) underwent 123I-FP-CIT SPECT and clinical evaluation [Unified Parkinson's Disease Rating Scale (UPDRS) and Parkinson's Disease Quality of Life Scale (PDQL)] preoperatively, 8 and 13 months after EMCS. Striatum-to-occipital cortex, caudate-to-occipital cortex and putamen-to-occipital cortex 123I-FP-CIT uptake ratios were calculated using the region of interest method.


RESULTS
Total and part III UPDRS scores significantly decreased at 8 and 13 months after stimulation (P=0.02 and 0.04, respectively); UPDRS part II and PDQL scores improved after 13 months (P=0.02 and 0.04, respectively). No significant differences in 123I-FP-CIT uptake ratios between baseline and follow-up were found in the examined regions. However, a progressive reduction in 123I-FP-CIT uptake ratios in the striatum contralateral to the implant was found. In contrast, no further decrease in 123I-FP-CIT uptake ratios was detected in the striatum ipsilateral to the implant. There were no correlations between changes in 123I-FP-CIT uptake ratios with disease duration, changes in medication dosage and motor UPDRS scores.


CONCLUSIONS
Despite a small but highly selected sample of advanced PD patients, our results showed that no further dopamine transporter reduction occurred in the striatum ipsilateral to the implant side. This finding could lead to the hypothesis that EMCS might elicit a 'neuroprotective' effect, as suggested by significant clinical benefits.
aDepartment of Bioimages and Radiological Sciences, Institute of Nuclear Medicine, Catholic University of Sacred Heart, Largo A. Gemelli, 8 00168 Rome, Italy. danieladigiuda@rm.unicatt.it
Daniela
D
Di Giuda
Maria L
ML
Calcagni
Manuela
M
Totaro
Fabrizio
F
Cocciolillo
Carla
C
Piano
Francesco
F
Soleti
Alfonso
A
Fasano
Beatrice
B
Cioni
Anna R
AR
Bentivoglio
Alessandro
A
Giordano
D046690:Deep Brain Stimulation; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000601:surgery*; D017072:Neostriatum / Q000378:metabolism*; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D009435:Synaptic Transmission; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes
D050483:Dopamine Plasma Membrane Transport Proteins; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; D004298:Dopamine