Ruxanda Lungu¹, Francisca F Fernandes¹, Tiago Fleming Outeiro², and Noam Shemesh^1
1Shemesh Lab, Champalimaud Foundation, Lisbon, Portugal, ²Experimental Neurodegeneration, University of Goettingen, Goettingen, Germany

Parkinson's disease (PD) is associated with irreparable damage to dopaminergic neurons in brain areas involved in movement. Frequently, a very early symptom is an impaired sense of smell, but the associated brain-wide mechanisms remain unclear. Here, we report on aberrations in BOLD-fMRI responses along olfactory pathway in a PD mouse model. We find decreased activation, especially in the main olfactory bulb, olfactory tubercle and piriform cortex in PD mice when compared to healthy controls upon olfactory stimulation.

Sooyeon Ji¹, Eun-Jung Choi¹, Beomseok Sohn², Eung Yeop Kim³, Kyoungwon Baik², Na-Young Shin⁴, Won-Jin Moon⁵, Seongbeom Park⁶, Soohwa Song⁶, Phil Hyu Lee⁷, Dong Hoon Shin⁶, and Jongho Lee^1
1Seoul National University, Seoul, Korea, Republic of, ²Severance Hospital, Seoul, Korea, Republic of, ³Department Radiology, Samsung Medical Center, Seoul, Korea, Republic of, ⁴Department Radiology, Catholic University of Korea, Seoul, Korea, Republic of, ⁵Department of Radiology, Konkuk University Medical Center, Seoul, Korea, Republic of, ⁶Heuron Co. Ltd., Incheon, Korea, Republic of, ⁷Department of Neurology, Severance Hospital, Seoul, Korea, Republic of

The reproducibility of the recently proposed sandwich spatial saturation neuromelanin (sandwichNM) imaging, which uses product sequences, is evaluated by a multi-center/multi-vendor traveling-subject study. Additionally, test-retest scans acquiring data in two different days are performed and evaluated. When compared to a conventional MT-weighted GRE NM imaging method, sandwichNM demonstrates higher contrast ratios and smaller variations across scanners, and higher intra-class coefficient and lower coefficient of variation in the test and retest scans, revealing higher reproducibility over the conventional method.

Laetitia Jeancolas^1,2, Sandy Mournet^1,2,3,4, Cécile Gallea^1,2, Emma Biondetti^1,2, Graziella Mangone^3,5,6, Lydia Chougar^1,2,3,4, Nicolas Villain⁷, Rahul Gaurav^1,2, Habib Benali⁸, Badr-Eddine Benkelfat⁹, Isabelle Arnulf^3,10, Marie-Odile Habert^3,11, Dijana Petrovska-Delacrétaz⁹, Marie Vidailhet^2,3,6, Jean-Christophe Corvol^3,5,6, and Stéphane Lehéricy^1,2,3,4
1Centre de NeuroImagerie de Recherche – CENIR, Institut du Cerveau – ICM, Paris, France, ²Team “Movement Investigations and Therapeutics”(MOV'IT), Institut du Cerveau – ICM, Paris, France, ³Sorbonne University, Inserm, CNRS, Paris Brain Institute - ICM, Paris, France, ⁴Department of Neuroradiology, AP-HP, Pitié-Salpêtrière Hospital, Paris, France, ⁵Clinical Investigation Center for Neurosciences, Pitié-Salpêtrière Hospital, INSERM, Paris, France, ⁶Department of Neurology, AP-HP, Pitié-Salpêtrière Hospital, Paris, France, ⁷AP-HP, Pitié-Salpêtrière Hospital, Paris, France, ⁸PERFORM Centre, Electrical & Computer Engineering Department, Concordia University, Montreal, QC, Canada, ⁹Laboratoire SAMOVAR, Télécom SudParis, Institut Polytechnique de Paris, Paris, France, ¹⁰Sleep disorders unit, AP-HP, Pitié-Salpêtrière Hospital, Paris, France, ¹¹Department of Nuclear Medicine, AP-HP, Pitié-Salpêtrière Hospital, Paris, France

We studied the neural mechanisms underlying Parkinson’s disease (PD) speech impairments. We assessed the relationships between the speech impairment in PD and changes in the nigrostriatal system (DAT imaging and neuromelanin-sensitive MRI) and in resting state fMRI functional connectivity within cortical language networks. Patients presented speech alterations depending on gender. Dopaminergic loss in the striatum as well as functional connectivity between the basal ganglia and the cortex were related to PD speech impairments in men, whereas in women only functional connectivity seemed to play a role in PD speech deterioration.

Xuan Wei¹ and Jinxia Zhu^2
1Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China, ²MR Collaboration, Siemens Healthcare Ltd., Beijing, China

In this study, we used surface-based morphometry analysis to evaluate the correlation between structural alterations in the brains of Parkinson’s disease (PD) subjects, impaired cognition, and gait. Our results showed that cortical surface area in the left lateral temporal cortex (LTC) and right inferior parietal cortex (IPC) was significantly larger in the PD subjects compared to the healthy subjects. Furthermore, these cortical structural changes were associated with gait impairments in the PD subjects. Therefore, surface area-based analysis is a useful tool for assessing progression of gait impairments in PD subjects. 

Vicente Jose Ferrer-Gallardo¹, Teresa Esteban-Peñalba², César Caballero-Gaudes¹, and Pedro M Paz-Alonso^2
1Signal processing in neuroimaging, Basque Center on Cognition Brain and language, San Sebastian, Spain, ²Language and memory control, Basque Center on Cognition Brain and language, San Sebastian, Spain

This study sheds light on the relationship between the thalamic nuclei volume and their lateralization with cognitive and motor scores in PD. Two partial least squares analyses were performed between the volume or laterality indexes of all nuclei and clinical and cognitive scores. Cognitive deficits in semantic fluency and symbols and digits tests in PD are related to ventral, central and medial thalamic nuclei rather than to specific nuclei differences, except for the right-AV. Motor deterioration seems to be reflected in specific lateralization of the medial  and pulvinar areas.

Marta Lancione^1,2, Graziella Donatelli^2,3, Eleonora Del Prete⁴, Nicole Campese⁴, Daniela Frosini⁴, Matteo Cencini^1,2, Mauro Costagli^1,5, Giacomo Lucchi⁶, Michela Tosetti^1,2, Massimiliano Godani⁷, Dario Arnaldi^5,8, Michele Terzaghi^9,10, Claudio Pacchetti¹¹, Pietro Cortelli^12,13, Enrica Bonanni⁴, Roberto Ceravolo⁴, and Mirco Cosottini^6
1IRCCS Stella Maris, Pisa, Italy, ²Imago7 Research Foundation, Pisa, Italy, ³Neuroradiology Unit, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy, ⁴Neurology Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy, ⁵Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Sciences (DINOGMI), University of Genoa, Genoa, Italy, ⁶Neuroradiology Unit, Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy, ⁷Neurology Unit, Sant'Andrea Hospital, La Spezia, Italy, ⁸IRCCS Ospedale Policlinico San Martino, Genoa, Italy, ⁹Unit of Sleep Medicine and Epilepsy, IRCCS Mondino Foundation, Pavia, Italy, ¹⁰Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy, ¹¹Parkinson's Disease and Movement Disorders Unit, IRCCS Mondino Foundation, Pavia, Italy, ¹²Clinica Neurologica Rete Metropolitana, IRCCS Istituto Scienze Neurologiche Bologna, Bologna, Italy, ¹³Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy

iRBD is a prodromal stage of α-synucleinopathies, like PD. Iron deposition is increased in the substantia nigra of PD patients, mainly in Nigrosome-1 (N1).  Here, we estimated N1 iron content in PD, iRBD patients and healthy controls using QSM at 7T to investigate group differences and correlation with disease duration. PD patients showed increased N1 susceptibility compared to controls and iRBD patients but no correlation with disease duration. N1 susceptibility in iRBD patients was not different from controls but correlated with disease duration. Hence, in prodromal stages of α-synucleinopathies, QSM can reveal progressive N1 iron accumulation as the disease evolves.

Pohchoo Seow¹, Yao-Chia Shih², Septian Hartono³, Weiling Lee¹, Say Lee Chong¹, Celeste Yan Teng Chen ⁴, Eng King Tan³, and Ling Ling Chan^1
1Diagnostic Radiology, Singapore General Hospital, Singapore, Singapore, ²Graduate Institution of Medicine, Yuan Ze University, Taiwan, Taiwan, ³Department of Neurology, National Neuroscience Institute, Singapore, Singapore, ⁴Neurology, National Neuroscience Institute, Singapore, Singapore

Altered brain cholinergic activity has gained attention in Parkinson’s disease (PD). However, the effects of cholinergic dysregulation on motor and cognitive functions remain unclear. This is partly contributed by the limited capability of conventional MRI techniques to detect microstructural changes in the deep brain. We evaluated the cholinergic projections in 36 PD patients and 58 asymptomatic healthy controls using diffusion MRI connectometry. Local diffusion changes in the cholinergic projections showed significant correlations to motor onset, and clinical motor scores in PD compared to control subjects. Our results suggest underlying neuronal inflammation and compensatory mechanisms in early PD-related neural dysfunction.

Megan Aumann¹, Tony Phan¹, Kilian Hett¹, Ryan Darby¹, and Daniel Claassen^1
1Neurology, Vanderbilt University, Nashville, TN, United States

Emerging evidence has implicated the cerebellum in not just motor, but cognitive and behavioral roles in the brain. Previous research in cerebellar diseases have reported impulsive behaviors, but it is unknown if Essential Tremor (ET) patients present with these behaviors and where they localize. Here, in 105 ET patients, we measured disinhibition using the Frontal Systems Behavior Scale (FrSBe) and assessed the relationship between disinhibition scores and grey matter volume in the cerebellum, as well as functional correlates of disinhibition-related grey matter atrophy. These results are the first to evaluate neurobiological changes associated with disinhibition in ET.

Jisoo Kim¹, Andrew S Willett², Grace F Crotty³, Merlyne Mesidor², Camden Bay⁴, Xiaoyin Xu⁵, Lei Qin⁶, Vikram Khurana², and Geoffrey S Young^1
1Neuroradiology, Brigham and Women's Hospital, Boston, MA, United States, ²Movement Disorders Division, Neurology, Brigham and Women's Hospital, Boston, MA, United States, ³Neurology, Massachusetts General Hospital, Boston, MA, United States, ⁴Center for Clinical Investigation, Brigham and Women's Hospital, Boston, MA, United States, ⁵Diagnostic Radiology, Brigham and Women's Hospital, Boston, MA, United States, ⁶Imaging, Dana Farber Cancer Institute, Boston, MA, United States

For screening and diagnosis of Parkinson disease (PD), progressive supranuclear palsy (PSP), and multiple system atrophy-parkinsonian/cerebellar subtypes (MSA-P/MSA-C), we propose a two-step decision tree using a novel MRI biomarker and volumetric measures. MRIs from 50 MSA-C, 22 MSA-P, 50 PSP, 50 PD, and 172 age/legal-sex-matched control were used for fully automated volumetric analysis of the brain and brainstem. Sensitivity/specificity for diseased vs control was 90.1/90.7%. Then, a comprehensive tree with the diseased group yielded sensitivity/specificity of 81.9/93.0% (MSA), 94.0/88.5% (MSA-C), 54.5/96.0% (MSA-P), 74.0/86.0% (PD), 76.0/98.4% (PSP). We provide a reproducible and specific diagnostic tool for screening and initial differential diagnosis.

Mark Lowe¹, Jian Lin¹, Ajay Nemani¹, Sean Nagel², and Stephen Jones^1
1Imaging Institute, Cleveland Clinic, Cleveland, OH, United States, ²Neurosurgery, Cleveland Clinic, Cleveland, OH, United States

High Intensity Focused Ultrasound (HIFU) in now entering clinical practice, for example to treat essential tremor by causing small lesions in the thalamus. Due to small size of treatment lesions, treatment success depends critically on targeting, which is classically done using measurements and landmarks. We explore an alternative method using functional imaging to guide targeting, specifically using 7T resting state connectivity. We present preliminary data of the patterns of connectivity possible with 7T using a concatenated series of 18 healthy subjects.