BoNT-A related changes of cortical activity in patients suffering from severe hand paralysis with arm spasticity following ischemic stroke

• Published in: Journal of the neurological sciences 2012-08, Vol.319 (1), p.89-95
• Main Authors: Veverka, Tomáš, Hluštík, Petr, Tomášová, Zuzana, Hok, Pavel, Otruba, Pavel, Král, Michal, Tüdös, Zbyněk, Zapletalová, Jana, Herzig, Roman, Krobot, Alois, Kaňovský, Petr
• Format: Article
• Language: English
• Subjects: Adult; Aged; Arm - physiopathology; Arm spasticity; Biological and medical sciences; Botulinum toxin; Botulinum Toxins, Type A - pharmacology; Botulinum Toxins, Type A - therapeutic use; Brain Ischemia - complications; Brain Ischemia - physiopathology; Brain Mapping; Cerebral Cortex - drug effects; Cerebral Cortex - physiopathology; Female; Functional MRI; Humans; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Muscle Spasticity - drug therapy; Muscle Spasticity - etiology; Muscle Spasticity - physiopathology; Neurology; Neuromuscular Agents - pharmacology; Neuromuscular Agents - therapeutic use; Paralysis - drug therapy; Paralysis - etiology; Paralysis - physiopathology; Psychomotor Performance - drug effects; Psychomotor Performance - physiology; Stroke; Stroke - complications; Stroke - physiopathology; Vascular diseases and vascular malformations of the nervous system
• ISSN: 0022-510X; 1878-5883
• DOI: 10.1016/j.jns.2012.05.008

Abstract Background Investigations were performed to localize and analyze the botulinum toxin (BoNT-A) related changes of cerebral cortex activation in chronic stroke patients suffering from severe hand paralysis with arm spasticity. Effects on task- related cerebral activation were evaluated by functional magnetic resonance imaging (fMRI). Methods 14 patients (5 males, 9 females, mean age 55.3 years) suffering from upper limb post-stroke spasticity were investigated. The change of arm spasticity was assessed by using the modified Ashworth scale (MAS). FMRI sessions were performed before (W0), four weeks (W4) and 11 weeks (W11) after BoNT-A application. Patients were scanned while performing imaginary movement with the impaired hand. Group fMRI analysis included patient age as a covariate. Results BoNT-A treatment was effective in alleviation of arm spasticity. Mean MAS was at Week 0: 2.5 (SD 0.53), at Week 4: 1.45 (SD 0.38), at Week 11: 2.32 (SD 0.44). Task-related fMRI prior to the treatment showed extensive activation of bilateral frontoparietal sensorimotor cortical areas, anterior cingulate gyrus, pallidum, thalamus and cerebellum. Effective BoNT-A treatment (W4) resulted in partial reduction of active network volume in most of the observed areas, whereas BoNT-free data (W11) revealed further volume reduction in the sensorimotor network. On direct comparison, significant activation decreases associated with BoNT-A treatment were located in areas outside the classical sensorimotor system, namely, ipsilesional lateral occipital cortex, supramarginal gyrus and precuneus cortex. On comparison of W4 and W11, no activation increases were found, instead, activation further decreased in ipsilesional insular cortex, contralesional superior frontal gyrus and bilateral frontal pole. Conclusions Whole brain activation patterns during BoNT-A treatment of post-stroke arm spasticity and further follow up document predominantly gradual changes both within and outside the classical sensorimotor system.