Electrophysiological assessment of the effect of intrathecal baclofen in dystonic children.
OBJECTIVE
To evaluate the effect of intrathecal baclofen in a group of dystonic children using electrophysiological procedures previously validated in spastic children.


METHODS
Seven children (aged 2-16 years) with dystonia of various aetiologies (dyskinetic cerebral palsy, pantothenate kinase-associated neurodegeneration and Aicardi-Goutières syndrome) underwent transcranial magnetic stimulation, H-reflex and flexor reflex studies before and after intrathecal injection of baclofen. The Barry-Albright Dystonia Scale (BADS) was used for clinical evaluation of dystonia.


RESULTS
Motor-evoked potentials, present in 2 of 5 patients before baclofen, were preserved after injection. Before baclofen, H reflex was present in 6 of 7 patients (mean H(max)/M(max:) 0.45+/-0.21). It was markedly reduced after the injection (mean H(max)/M(max:) 0.09+/-0.11) (P<0.001). Area of flexor reflex significantly decreased after baclofen (P=0.047), while threshold significantly increased (P=0.01). No significant clinical improvement of the BADS scores was observed (P=0.058).


CONCLUSIONS
These electrophysiological procedures, previously demonstrated to quantify the action of intrathecal baclofen in spastic adults and children, also appear sensitive in dystonic children. The electrophysiological changes are consistent with primarily spinal sites of action of baclofen. They appear more sensitive than clinical evaluation.
Dachy
Bernard
B
Department of Rehabilitation for Neurologic Diseases, CHU Brugmann (ULB), Place Van Gehuchten 4, B-1020 Brussels, Belgium. bernard.dachy@chu-brugmann.be
Dan
Bernard
B
D000328:Adult; D001418:Baclofen / Q000008:administration & dosage*; D002547:Cerebral Palsy / Q000150:complications; D002648:Child; D002675:Child, Preschool; D004421:Dystonia / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology*; D019054:Evoked Potentials, Motor / Q000187:drug effects*; D005260:Female; D006181:H-Reflex / Q000187:drug effects; D006801:Humans; D007278:Injections, Spinal; D008297:Male; D009125:Muscle Relaxants, Central / Q000008:administration & dosage*; D019636:Neurodegenerative Diseases / Q000150:complications
D009125:Muscle Relaxants, Central; D001418:Baclofen