Consensus Paper: Radiological Biomarkers of Cerebellar Diseases

Abstract

Hereditary and sporadic cerebellar ataxias represent a vast and still growing group of diseases whose diagnosis and differentiation cannot only rely on clinical evaluation. Brain imaging including magnetic resonance (MR) and nuclear medicine techniques allows for characterization of structural and functional abnormalities underlying symptomatic ataxias. These methods thus constitute a potential source of radiological biomarkers, which could be used to identify these diseases and differentiate subgroups of them, and to assess their severity and their evolution. Such biomarkers mainly comprise qualitative and quantitative data obtained from MR including proton spectroscopy, diffusion imaging, tractography, voxel-based morphometry, functional imaging during task execution or in a resting state, and from SPETC and PET with several radiotracers. In the current article, we aim to illustrate briefly some applications of these neuroimaging tools to evaluation of cerebellar disorders such as inherited cerebellar ataxia, fetal developmental malformations, and immune-mediated cerebellar diseases and of neurodegenerative or early-developing diseases, such as dementia and autism in which cerebellar involvement is an emerging feature. Although these radiological biomarkers appear promising and helpful to better understand ataxia-related anatomical and physiological impairments, to date, very few of them have turned out to be specific for a given ataxia with atrophy of the cerebellar system being the main and the most usual alteration being observed. Consequently, much remains to be done to establish sensitivity, specificity, and reproducibility of available MR and nuclear medicine features as diagnostic, progression and surrogate biomarkers in clinical routine.

Classifying suicidal behavior with resting‐state functional connectivity and structural neuroimaging

“…Additionally, the left putamen had increased RSFC with the vermis in SUIC patients. While studies of cerebellar disease have shown the vermis and putamen are both a part of motor circuitry , this finding may also implicate them in a cognitive/emotion regulation role. This is supported by structural neuroimaging research, which has found the vermis to be associated with several affective disorders .…”

Regional Cerebral Disease Progression in Friedreich's Ataxia: A Longitudinal Diffusion Tensor Imaging Study

“…3 Imaging biomarkers of disease progression are desirable in view of future trials in inherited ataxias. 4 MRI has previously demonstrated brain damage in FRDA in form of regional atrophy of the medulla, peridentate cerebellar white matter (WM) and superior cerebellar peduncles in T1-weighted imaging [5][6][7][8][9] and of change of microstructural diffusion-related characteristics of WM tracts of the brainstem, cerebellar peduncles, cerebellum and supratentorial structures in diffusion-weighted, or diffusion tensor imaging (DTI). [10][11][12][13][14][15] Regional atrophy and microstructural diffusion-related changes were however, seen to correlate with disease duration and severity of clinical deficit in several crosssectional studies.…”

Standardized Assessment of Hereditary Ataxia Patients in Clinical Studies

“…Oculomotor disturbances are a common and often early sign in most hereditary ataxias. Specific oculomotor abnormalities, such as saccade slowing, are helpful in the diagnosis of hereditary atxias . Presence or absence of oculomotor signs is recorded by the INAS together with nonataxia signs.…”

“…Specific oculomotor abnormalities, such as saccade slowing, are helpful in the diagnosis of hereditary atxias. 56 Presence or absence of oculomotor signs is recorded by the INAS together with nonataxia signs. Quantitative recording of eye movements has been performed in several monocentre studies.…”