title: Substantia nigra in Parkinson's disease: a multimodal MRI comparison between early and advanced stages of the disease.
abstract: This study focused on the substantia nigra (SN) in Parkinson's disease (PD). We measured its area and volume, mean diffusivity (MD), fractional anisotropy (FA) and iron concentration in early and late PD and correlated the values with clinical scores. Twenty-two early PD (EPD), 20 late PD (LPD) and 20 healthy subjects (age 64.7 ± 4.9, 60.5 ± 6.1, and 61 ± 7.2 years, respectively) underwent 1.5 T MR imaging with double-TI-IR T1-weighted, T2*-weighted and diffusion tensor imaging scans. Relative SN area, MD, FA and R2* were measured in ROIs traced on SN. Correlation with Unified Parkinson Disease Rating Scale (UPDRS) scores was assessed. In LPD, the SN area was significantly reduced with respect to EPD (p = 0.04) and control subjects (p < 0.001). In EPD, the SN area was also significantly smaller than in controls (p = 0.006). Similarly, the SN volume significantly differed between LPD and controls (p = 0.001) and between EPD and LPD (p = 0.049), while no significant differences were found between controls and EPD. Both SN area (r = 0.47, p = 0.004) and volume (r = 0.46, p = 0.005) correlated with UPDRS scores. At 1.5 T, SN morphological measurements were sensitive to early PD changes and able to track the disease progression, while MD and FA measures and relaxometry did not provide significant results.
authors: Neuroradiology Department, IRCCS Foundation Neurological Institute Carlo Besta, Via Celoria, 11, 20133, Milan, Italy, aquino@istituto-besta.it.
authors: Domenico
authors: D
authors: Aquino
authors: Valeria
authors: V
authors: Contarino
authors: Alberto
authors: A
authors: Albanese
authors: Ludovico
authors: L
authors: Minati
authors: Laura
authors: L
authors: Farina
authors: Marina
authors: M
authors: Grisoli
authors: Luigi
authors: L
authors: Romita
authors: Antonio Emanuele
authors: AE
authors: Elia
authors: Antonio
authors: A
authors: Elia
authors: Maria Grazia
authors: MG
authors: Bruzzone
authors: Luisa
authors: L
authors: Chiapparini
mesh_terms: D016880:Anisotropy; D038524:Diffusion Magnetic Resonance Imaging; D056324:Diffusion Tensor Imaging; D018450:Disease Progression; D005260:Female; D006801:Humans; D007501:Iron / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D010300:Parkinson Disease / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology*; D012720:Severity of Illness Index; D013378:Substantia Nigra / Q000473:pathology* / Q000503:physiopathology*
chemical_list: D007501:Iron