Nejvíce citovaný článek - PubMed ID 26530223
Linking Essential Tremor to the Cerebellum: Physiological Evidence
Although recently conceptualized as a neural node essential for a vast spectrum of associative and cognitive processes, the cerebellum has largely eluded attention in the research of aging, where it is marginalized mainly to structural analyses. In the current cross-sectional study of 67 healthy subjects of various ages (20 to 76 years), we sought to provide a comprehensive, multimodal account of age-related changes in the cerebellum during predictive motor timing, which was previously shown to engage this structure. We combined behavioral assessments of performance with functional MRI and voxel-based morphometry using an advanced method to avoid cerebellar deformation and registration imprecisions inherent to the standard processing at the whole-brain level. Higher age was surprisingly associated with stable behavioral performance during predictive motor timing, despite the massive decrease of infratentorial gray matter volume of a far higher extent than in the supratentorial region, affecting mainly the posterior cerebellar lobe. Nonetheless, this very area showed extensive hyperactivation directly correlated with age. The same region had decreased connectivity with the left caudate and increased connectivity with the left fusiform gyrus, the right pallidum, the hippocampus, and the lingual gyrus. Hence, we propose to extend the scaffolding theory of aging, previously limited mainly to the frontal cortices, to include also the cerebellum, which is likewise suffering from atrophy to a far greater extent than the rest of the brain and is similarly counteracting it by bilateral hyperactivation.
- Klíčová slova
- Cerebellar aging, Functional connectivity, Voxel-based morphometry, fMRI,
- MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mozeček patologie fyziologie MeSH
- pohybová aktivita fyziologie MeSH
- pozornost fyziologie MeSH
- průřezové studie MeSH
- senioři MeSH
- stárnutí patologie fyziologie MeSH
- zdravé stárnutí patologie fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Time perception is an essential element of conscious and subconscious experience, coordinating our perception and interaction with the surrounding environment. In recent years, major technological advances in the field of neuroscience have helped foster new insights into the processing of temporal information, including extending our knowledge of the role of the cerebellum as one of the key nodes in the brain for this function. This consensus paper provides a state-of-the-art picture from the experts in the field of the cerebellar research on a variety of crucial issues related to temporal processing, drawing on recent anatomical, neurophysiological, behavioral, and clinical research.The cerebellar granular layer appears especially well-suited for timing operations required to confer millisecond precision for cerebellar computations. This may be most evident in the manner the cerebellum controls the duration of the timing of agonist-antagonist EMG bursts associated with fast goal-directed voluntary movements. In concert with adaptive processes, interactions within the cerebellar cortex are sufficient to support sub-second timing. However, supra-second timing seems to require cortical and basal ganglia networks, perhaps operating in concert with cerebellum. Additionally, sensory information such as an unexpected stimulus can be forwarded to the cerebellum via the climbing fiber system, providing a temporally constrained mechanism to adjust ongoing behavior and modify future processing. Patients with cerebellar disorders exhibit impairments on a range of tasks that require precise timing, and recent evidence suggest that timing problems observed in other neurological conditions such as Parkinson's disease, essential tremor, and dystonia may reflect disrupted interactions between the basal ganglia and cerebellum.The complex concepts emerging from this consensus paper should provide a foundation for further discussion, helping identify basic research questions required to understand how the brain represents and utilizes time, as well as delineating ways in which this knowledge can help improve the lives of those with neurological conditions that disrupt this most elemental sense. The panel of experts agrees that timing control in the brain is a complex concept in whom cerebellar circuitry is deeply involved. The concept of a timing machine has now expanded to clinical disorders.
- Klíčová slova
- Cerebellum, Climbing fiber, Consensus, Movement, Temporal processing, Timing,
- MeSH
- lidé MeSH
- mozeček fyziologie patofyziologie MeSH
- neurony fyziologie MeSH
- vnímání času fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- konsensus - konference MeSH
Basic epilepsy teachings assert that seizures arise from the cerebral cortex, glossing over infratentorial structures such as the cerebellum that are believed to modulate rather than generate seizures. Nonetheless, ataxia and other clinical findings in epileptic patients are slowly but inevitably drawing attention to this neural node. Tracing the evolution of this line of inquiry from the observed coincidence of cerebellar atrophy and cerebellar dysfunction (most apparently manifested as ataxia) in epilepsy to their close association, this review considers converging clinical, physiological, histological, and neuroimaging evidence that support incorporating the cerebellum into epilepsy pathology. We examine reports of still controversial cerebellar epilepsy, studies of cerebellar stimulation alleviating paroxysmal epileptic activity, studies and case reports of cerebellar lesions directly associated with seizures, and conditions in which ataxia is accompanied by epileptic seizures. Finally, the review substantiates the role of this complex brain structure in epilepsy whether by coincidence, as a consequence of deleterious cortical epileptic activity or antiepileptic drugs, or the very cause of the disease.
- Klíčová slova
- Ataxia, atrophy, epilepsy, seizures, stimulation,
- Publikační typ
- časopisecké články MeSH