Arterial spin labelling reveals prolonged arterial arrival time in idiopathic Parkinson's disease.
Idiopathic Parkinson's disease (IPD) is the second most common neurodegenerative disease, yet effective disease modifying treatments are still lacking. Neurodegeneration involves multiple interacting pathological pathways. The extent to which neurovascular mechanisms are involved is not well defined in IPD. We aimed to determine whether novel magnetic resonance imaging (MRI) techniques, including arterial spin labelling (ASL) quantification of cerebral perfusion, can reveal altered neurovascular status (NVS) in IPD. Fourteen participants with IPD (mean ± SD age 65.1 ± 5.9 years) and 14 age and cardiovascular risk factor matched control participants (mean ± SD age 64.6 ± 4.2 years) underwent a 3T MRI scan protocol. ASL images were collected before, during and after a 6 minute hypercapnic challenge. FLAIR images were used to determine white matter lesion score. Quantitative images of cerebral blood flow (CBF) and arterial arrival time (AAT) were calculated from the ASL data both at rest and during hypercapnia. Cerebrovascular reactivity (CVR) images were calculated, depicting the change in CBF and AAT relative to the change in end-tidal CO2. A significant (p = 0.005) increase in whole brain averaged baseline AAT was observed in IPD participants (mean ± SD age 1532 ± 138 ms) compared to controls (mean ± SD age 1335 ± 165 ms). Voxel-wise analysis revealed this to be widespread across the brain. However, there were no statistically significant differences in white matter lesion score, CBF, or CVR between patients and controls. Regional CBF, but not AAT, in the IPD group was found to correlate positively with Montreal cognitive assessment (MoCA) scores. These findings provide further evidence of alterations in NVS in IPD.
Department of Neurology, Royal Preston Hospital, Preston, UK ; Centre for Imaging Science, Institute of Population Health, University of Manchester, UK.
Sarah
S
Al-Bachari
Centre for Imaging Science, Institute of Population Health, University of Manchester, UK.
Laura M
LM
Parkes
Centre for Imaging Science, Institute of Population Health, University of Manchester, UK.
Rishma
R
Vidyasagar
Department of Neurology, Royal Preston Hospital, Preston, UK.
Martha F
MF
Hanby
Institute of Brain, Behaviour and Mental Health, University of Manchester, UK.
Vivek
V
Tharaken
Institute of Brain, Behaviour and Mental Health, University of Manchester, UK.
Iracema
I
Leroi
Department of Neurology, Royal Preston Hospital, Preston, UK ; School of Medicine, University of Manchester, UK.
Hedley C A
HC
Emsley
D000368:Aged; D001776:Blood Circulation Time / Q000379:methods; D002536:Cerebral Arteries / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis* / Q000503:physiopathology*; D013113:Spin Labels; D013997:Time Factors
D013113:Spin Labels
3T, 3 Tesla; AAT, arterial arrival time; AD, Alzheimer’s disease; ASL, arterial spin labelling; Arterial arrival time; Arterial spin labelling; CBF, cerebral blood flow; CO2, carbon dioxide; CV, cerebrovascular; CVD, cerebrovascular disease; CVR, cerebrovascular reactivity; CVRAAT, cerebrovascular reactivity measures of arterial arrival time; CVRCBF, cerebrovascular reactivity measures of cerebral blood flow; Cerebral blood flow; Cerebrovascular reactivity; DS, digit span; DSST, digit symbol substitution test; DWMH, deep white matter hyperintensity; EPI, echo planar imaging; ETCO2, end-tidal carbon dioxide; FAS, (verbal) fluency assessment scale; FLAIR, fluid attenuation inversion recovery; FWE, family-wise error; HAM-D, Hamilton depression rating scale; IPD, idiopathic Parkinson's disease; Idiopathic Parkinson's disease; L-dopa, levodopa; LARS, Lille apathy rating scale; LEDD, levodopa equivalent daily dose; MCI, mild cognitive impairment; MRI, magnetic resonance imaging; MoCA; MoCA, Montreal cognitive assessment; NPI, neuropsychiatric inventory; NVU, Neurovascular unit; O2−, oxygen; PET, positron emission tomography; PIGD, Postural instability and gait disorder; PL, parietal lobe; PVH, periventricular hyperintensity; ROI, region of interest; SPECT, single positron emission computed tomography; SPM, statistical parametric mapping; STAR, signal targeting with alternating radiofrequency; TD, tremor dominant; TE, echo time; TI, inversion time; TL, temporal lobe; TMT-B, trail making test B; TR, repetition time; UKPDS BB, United Kingdom Parkinson's Disease Society Brain Bank; UPDRS, Unified Parkinson's disease Rating Scale; WAIS-R, Wechsler adult intelligence scale-revised; WML, white matter lesion; fMRI, functional magnetic resonance imaging