BoNT-A related changes of cortical activity in patients suffering from severe hand paralysis with arm spasticity following ischemic stroke.
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.
Department of Neurology, Faculty of Medicine and Dentistry, Palacký University and University Hospital, Olomouc, Czech Republic. veverka.tomas@seznam.cz
Tomáš
T
Veverka
Petr
P
Hluštík
Zuzana
Z
Tomášová
Pavel
P
Hok
Pavel
P
Otruba
Michal
M
Král
Zbyněk
Z
Tüdös
Jana
J
Zapletalová
Roman
R
Herzig
Alois
A
Krobot
Petr
P
Kaňovský
D000328:Adult; D000368:Aged; D001132:Arm / Q000503:physiopathology; D019274:Botulinum Toxins, Type A / Q000494:pharmacology / Q000627:therapeutic use*; D002545:Brain Ischemia / Q000150:complications* / Q000503:physiopathology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009128:Muscle Spasticity / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D009465:Neuromuscular Agents / Q000494:pharmacology / Q000627:therapeutic use*; D010243:Paralysis / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology; D020521:Stroke / Q000150:complications* / Q000503:physiopathology
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A; C545476:incobotulinumtoxinA