Session Information
Date: Wednesday, June 22, 2016
Session Title: Parkinson's disease: Neuroimaging and neurophysiology
Session Time: 12:00pm-1:30pm
Location: Exhibit Hall located in Hall B, Level 2
Objective: The aim of this study was to determine the possible relation between pedunculopontine nucleus’ size (PPN) and occurrence of freezing in Parkinson’s disease (PD).
Background: Gait disorders represent a major problem in PD. In advanced forms, these symptoms are often refractory to dopaminergic therapies; it suggests the involvement of non-dopaminergic lesions such as the PPN.
Methods: Modified Fast Gray Matter Acquisition T1 Inversion Recovery images (FGATIR) was obtained using 3 T MRI during pre surgical procedure for subthalamic deep brain stimulation (STN-DBS) for PD. We localized precisely PPN and evaluated it semi quantitatively (0 = no atrophy, 1 = mild atrophy, 2 = moderate atrophy, 3 = severe atrophy). Clinical and neuropsychological data were collected.
Results: Thirty patients were included: 12 in PD freezer group (FOG +), 13 in PD non freezer group (FOG -) and 5 in control group (dystonic patients). The mean stereotactic coordinates for the rostral PPN were 6.58 mm lateral, 2.92 mm posterior to the posterior commissure (PC) and 8.87 mm caudal to the anterior commissure – posterior commissure (AC-PC) plane, those of the caudal PPN were 7.18 mm lateral, 4.07 mm posterior to the PC and 13.18 mm caudal to the AC-PC. Comparatively to the coordinates of Zrinzo, the greatest difference observed was 0.72 mm. In FOG + group, there were more PPN measured at 2 or 3 compared to FOG – group (27% versus 17%). However degree of PPN atrophy was not significantly different between the three groups.
Conclusions: Our results need to be confirmed by a larger study. Thus, a reduced size of PPN, could have a potential value as predictive factor of occurrence of axial signs in PD after STN-DBS. This study highlights the great interest of modified FGATIR MRI image to evaluate precisely the size of the PPN.
To cite this abstract in AMA style:
S. Chen, M. Tir, P. Monet, J.M. Constans, O. Godefroy, M. Lefranc, P. Krystkowiak. Relationship between freezing and pedunculopontine nucleus’ size in Parkinson’s disease: Semi quantitative analysis based on MRI with modified FGATIR sequence [abstract]. Mov Disord. 2016; 31 (suppl 2). https://www.mdsabstracts.org/abstract/relationship-between-freezing-and-pedunculopontine-nucleus-size-in-parkinsons-disease-semi-quantitative-analysis-based-on-mri-with-modified-fgatir-sequence/. Accessed October 22, 2026.« Back to 2016 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/relationship-between-freezing-and-pedunculopontine-nucleus-size-in-parkinsons-disease-semi-quantitative-analysis-based-on-mri-with-modified-fgatir-sequence/