Magnetization transfer and adiabatic R _1ρ MRI in the brainstem of Parkinson's disease

Background: In addition to classic midbrain pathology, Parkinson's disease (PD) is accompanied by changes in pontine and medullary brainstem structures. These additional abnormalities may underlie non-motor features as well as play a role in motor disability. Methods: Using novel magnetic resonance imaging (MRI) methods based on rotating frame adiabatic R _1ρ (i.e., measurements of longitudinal relaxation during adiabatic full passage pulses) and modified magnetization transfer (MT) MRI mapping, we sought to identify brainstem alterations in nine individuals with mild-moderate PD (off medication) and ten age-matched controls at 4 T. Results: We discovered significant differences in MRI parameters between midbrain and medullary brainstem structures in control subjects as compared to PD patients. Conclusions: These findings support the presence of underlying functional/structural brainstem changes in mild-moderate PD.