title: Neurodegeneration in friedreich's ataxia is associated with a mixed activation pattern of the brain. A fMRI study.
abstract: Friedreich's ataxia (FRDA) is associated with a distributed pattern of neurodegeneration in the spinal cord and the brain secondary to selective neuronal loss. We used functional MR Imaging (fMRI) to explore brain activation in FRDA patients during two motor-sensory tasks of different complexity, i.e. continuous hand tapping and writing of "8" figure, with the right dominant hand and without visual feedback. Seventeen FRDA patients and two groups of age-matched healthy controls were recruited. Task execution was monitored and recorded using MR-compatible devices. Hand tapping was correctly performed by 11 (65%) patients and writing of the "8" by 7 (41%) patients. After correction for behavioral variables, FRDA patients showed in both tasks areas of significantly lower activation in the left primary sensory-motor cortex and right cerebellum. Also left thalamus and right dorsolateral prefrontal cortex showed hypo-activation during hand tapping. During writing of the "8" task FRDA patients showed areas of higher activation in the right parietal and precentral cortex, globus pallidus, and putamen. Activation of right parietal cortex, anterior cingulum, globus pallidus, and putamen during writing of the "8" increased with severity of the neurological deficit. In conclusion fMRI demonstrates in FRDA a mixed pattern constituted by areas of decreased activation and areas of increased activation. The decreased activation in the primary motor cortex and cerebellum presumably reflects a regional neuronal damage, the decreased activation of the left thalamus and primary sensory cortex could be secondary to deafferentation phenomena, and the increased activation of right parietal cortex and striatum might have a possible compensatory significance.
authors.affiliation: Department of Clinical Physiopathology, Radiodiagnostic Section, University of Florence, Florence, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ginestroni
authors.forename: Stefano
authors.initials: S
authors.lastname: Diciotti
authors.forename: Paolo
authors.initials: P
authors.lastname: Cecchi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Pesaresi
authors.forename: Carlo
authors.initials: C
authors.lastname: Tessa
authors.forename: Marco
authors.initials: M
authors.lastname: Giannelli
authors.forename: Riccardo
authors.initials: R
authors.lastname: Della Nave
authors.forename: Elena
authors.initials: E
authors.lastname: Salvatore
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Salvi
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Dotti
authors.forename: Silvia
authors.initials: S
authors.lastname: Piacentini
authors.forename: Andrea
authors.initials: A
authors.lastname: Soricelli
authors.forename: Mirco
authors.initials: M
authors.lastname: Cosottini
authors.forename: Nicola
authors.initials: N
authors.lastname: De Stefano
authors.forename: Mario
authors.initials: M
authors.lastname: Mascalchi
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D005621:Friedreich Ataxia / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009410:Nerve Degeneration / Q000503:physiopathology*; D011597:Psychomotor Performance / Q000502:physiology