The complex phenomenological understanding of dystonia has transcended from the clinics to genetics, imaging and neurophysiology. One way in which electrophysiology will impact into the clinics are cases wherein a dystonic clinical presentation may not be typical or a "forme fruste" of the disorder. Indeed, the physiological imprints of dystonia are present regardless of its clinical manifestation. Underpinnings in the understanding of dystonia span from the peripheral, segmental and suprasegmental levels to the cortex, and various electrophysiological tests have been applied in the course of time to elucidate the origin of dystonia pathophysiology. While loss of inhibition remains to be the key finding in this regard, intricacies and variabilities exist, thus leading to a notion that perhaps dystonia should best be gleaned as network disorder. Interestingly, the complex process has now spanned towards the understanding in terms of networks related to the cerebellar circuitry and the neuroplasticity. What is evolving towards a better and cohesive view will be neurophysiology attributes combined with structural dynamic imaging. Such a sound approach will significantly lead to better therapeutic modalities in the future.

• Keywords
• Brain plasticity, Dystonia, Network disorder, Neurophysiology,
• MeSH
• Dystonic Disorders * MeSH
• Dystonia * MeSH
• Humans MeSH
• Cerebellum MeSH
• Cerebral Cortex MeSH
• Neurophysiology MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

Botulinum toxin type A (BoNT) is considered an effective therapeutic option in cervical dystonia (CD). The pathophysiology of CD and other focal dystonias has not yet been fully explained. Results from neurophysiological and imaging studies suggest a significant involvement of the basal ganglia and thalamus, and functional abnormalities in premotor and primary sensorimotor cortical areas are considered a crucial factor in the development of focal dystonias. Twelve BoNT-naïve patients with CD were examined with functional MRI during a skilled hand motor task; the examination was repeated 4 weeks after the first BoNT injection to the dystonic neck muscles. Twelve age- and gender-matched healthy controls were examined using the same functional MRI paradigm without BoNT injection. In BoNT-naïve patients with CD, BoNT treatment was associated with a significant increase of activation in finger movement-induced fMRI activation of several brain areas, especially in the bilateral primary and secondary somatosensory cortex, bilateral superior and inferior parietal lobule, bilateral SMA and premotor cortex, predominantly contralateral primary motor cortex, bilateral anterior cingulate cortex, ipsilateral thalamus, insula, putamen, and in the central part of cerebellum, close to the vermis. The results of the study support observations that the BoNT effect may have a correlate in the central nervous system level, and this effect may not be limited to cortical and subcortical representations of the treated muscles. The results show that abnormalities in sensorimotor activation extend beyond circuits controlling the affected body parts in CD even the first BoNT injection is associated with changes in sensorimotor activation. The differences in activation between patients with CD after treatment and healthy controls at baseline were no longer present.

• Keywords
• Botulinum toxin, Brain plasticity, Cervical dystonia, Functional MRI,
• MeSH
• Afferent Pathways diagnostic imaging   drug effects   MeSH
• Botulinum Toxins, Type A therapeutic use   MeSH
• Adult MeSH
• Oxygen blood   MeSH
• Middle Aged MeSH
• Humans MeSH
• Magnetic Resonance Imaging methods   MeSH
• Statistics, Nonparametric MeSH
• Neuromuscular Agents therapeutic use   MeSH
• Image Processing, Computer-Assisted MeSH
• Psychomotor Performance drug effects   MeSH
• Aged MeSH
• Sensorimotor Cortex diagnostic imaging   drug effects   MeSH
• Torticollis * diagnostic imaging   drug therapy   physiopathology   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Botulinum Toxins, Type A MeSH
• Oxygen MeSH
• Neuromuscular Agents MeSH