
Friedreich ataxia (FRDA) is a progressive neurodegenerative disorder defined by pathology within the cerebellum and spinal tracts. Although FRDA is most readily linked to motor and sensory dysfunctions, reported impairments in working memory and executive functions indicate that abnormalities may also extend to associations regions of the cerebral cortex and/or cerebello-cerebral interactions. To test this hypothesis, 29 individuals with genetically confirmed FRDA and 34 healthy controls performed a verbal n-back working memory task while undergoing functional magnetic resonance imaging. No significant group differences were evident in task performance. However, individuals with FRDA had deficits in brain activations both in the lateral cerebellar hemispheres, principally encompassing lobule VI, and the prefrontal cortex, including regions of the anterior insular and rostrolateral prefrontal cortices. Functional connectivity between these brain regions was also impaired, supporting a putative link between primary cerebellar dysfunction and subsequent cerebral abnormalities. Disease severity and genetic markers of disease liability were correlated specifically with cerebellar dysfunction, while correlations between behavioural performance and both cerebral activations and cerebello-cerebral connectivity were observed in controls, but not in the FRDA cohort. Taken together, these findings support a diaschisis model of brain dysfunction, whereby primary disease effects in the cerebellum result in functional changes in downstream fronto-cerebellar networks. These fronto-cerebellar disturbances provide a putative biological basis for the nonmotor symptoms observed in FRDA, and reflect the consequence of localized cerebellar pathology to distributed brain function underlying higher-order cognition.
cognition, Adult, Male, cerebellum, 150, Neuropsychological Tests, Severity of Illness Index, working memory, Young Adult, Cerebellar Diseases, Cerebellum, Image Processing, Computer-Assisted, Reaction Time, Humans, Cerebral Cortex, Brain Mapping, psychophysiological interaction, fMRI, functional connectivity, Middle Aged, Magnetic Resonance Imaging, Oxygen, Friedreich ataxia, Friedreich Ataxia, Case-Control Studies, Female, Cognition Disorders
cognition, Adult, Male, cerebellum, 150, Neuropsychological Tests, Severity of Illness Index, working memory, Young Adult, Cerebellar Diseases, Cerebellum, Image Processing, Computer-Assisted, Reaction Time, Humans, Cerebral Cortex, Brain Mapping, psychophysiological interaction, fMRI, functional connectivity, Middle Aged, Magnetic Resonance Imaging, Oxygen, Friedreich ataxia, Friedreich Ataxia, Case-Control Studies, Female, Cognition Disorders
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 47 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 10% | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 10% |
