title: Apparent diffusion coefficient of the superior cerebellar peduncle differentiates progressive supranuclear palsy from Parkinson's disease.
abstract: The early diagnosis of progressive supranuclear palsy (PSP) may be challenging, because of clinical overlapping features with Parkinson's disease (PD) and other parkinsonian syndromes such as the Parkinsonian variant of multiple system atrophy (MSA-P). Conventional MRI can help in differentiating parkinsonian disorders but its diagnostic accuracy is still unsatisfactory. On the basis of the pathological demonstration of superior cerebellar peduncle (SCP) atrophy in patients with PSP, we assessed the SCP apparent diffusion coefficient (ADC) values in patients with PSP, PD, and MSA-P in order to evaluate its differential diagnostic value in vivo. Twenty-eight patients with PSP (14 with possible-PSP and 14 with probable-PSP), 15 PD, 15 MSA-P, and 16 healthy subjects were studied by using diffusion weighted imaging (DWI). ADC was calculated in regions of interest defined in the left and right SCP by two clinically blinded operators. Intrarater (r = 0.98, P < 0.001) and interrater reliability (r = 0.97; P < 0.001) for SCP measurements were high. Patients with PSP had higher SCP rADC values (median 0.98 x 10(-3)mm(2)/s) than patients with PD (median 0.79 x 10(-3) mm(2)/s, P < 0.001), MSA-P (median 0.79 x 10(-3) mm(2)/s, P < 0.001), and healthy controls (median 0.80 x 10(-3) mm(2)/s, P < 0.001). DWI discriminated patients with PSP from PD and healthy subjects on the basis of SCP rADC individual values (100% sensitivity and specificity) and from patients with MSA-P (96.4% sensitivity and 93.3% specificity). The higher values of rADC in SCP of patients with PSP correspond with the in vivo microstructural feature of atrophy detected postmortem and provide an additional support for early discrimination between PSP and other neurodegenerative parkinsonisms.
authors.affiliation: Institute of Neurological Sciences, National Research Council, Piano Lago di Mangone, Cosenza, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nicoletti
authors.forename: Caterina
authors.initials: C
authors.lastname: Tonon
authors.forename: Raffaele
authors.initials: R
authors.lastname: Lodi
authors.forename: Francesca
authors.initials: F
authors.lastname: Condino
authors.forename: David
authors.initials: D
authors.lastname: Manners
authors.forename: Emil
authors.initials: E
authors.lastname: Malucelli
authors.forename: Maurizio
authors.initials: M
authors.lastname: Morelli
authors.forename: Fabiana
authors.initials: F
authors.lastname: Novellino
authors.forename: Sandra
authors.initials: S
authors.lastname: Paglionico
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Lanza
authors.forename: Demetrio
authors.initials: D
authors.lastname: Messina
authors.forename: Paolo
authors.initials: P
authors.lastname: Barone
authors.forename: Letterio
authors.initials: L
authors.lastname: Morgante
authors.forename: Mario
authors.initials: M
authors.lastname: Zappia
authors.forename: Bruno
authors.initials: B
authors.lastname: Barbiroli
authors.forename: Aldo
authors.initials: A
authors.lastname: Quattrone
mesh_terms: D000368:Aged; D002531:Cerebellum / Q000473:pathology*; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D013494:Supranuclear Palsy, Progressive / Q000175:diagnosis*