Mapping the cortical representation of the lumbar paravertebral muscles.
OBJECTIVE
The aim of this study was to map the cortical representation of the lumbar spine paravertebral (LP) muscles in healthy subjects.


METHODS
Transcranial magnetic stimulation (TMS) was employed to map the cortical representations of the LP muscles at two sites. Stimuli were applied to points on a grid representing scalp positions. The amplitude of motor evoked potentials (n=6) was averaged for each position.


RESULTS
The optimal site for evoking responses in the contralateral LP muscles was situated 1cm anterior and 4 cm lateral to the vertex. Ipsilateral responses were evoked from sites lateral to the optimal site for evoking contralateral responses. Contralateral responses were also obtained from areas anterior to the optimal site.


CONCLUSIONS
Maps of these muscles can be produced. The results suggest discrete contra- and ipsilateral cortical projections. Anterior sites at which excitation can be evoked may indicate projections arising in the SMA are involved.


CONCLUSIONS
This study provides normative data regarding the cortical representation of the paravertebral muscles and provides a technique for evaluating cortical motor plasticity in patients presenting with spinal pathologies.
O'Connell
N E
NE
Centre for Research in Rehabilitation, School of Health Sciences and Social Care, Brunel University, Borough Road, Uxbridge, Middlesex UB8 3PH, United Kingdom. neil.oconnell@brunel.ac.uk
Maskill
D W
DW
Cossar
J
J
Nowicky
A V
AV
D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology* / Q000528:radiation effects; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008161:Lumbosacral Region; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology / Q000528:radiation effects; D050781:Transcranial Magnetic Stimulation