Functional Organization of Primary Motor Cortex in Congenital Paraplegia Christoph Stippich, Julia Reinhardt, Michael Akbar Heidelberg, Basel

Primary Motor Cortex in Congenital Paraplegia Purpose MMC: Neural tube defect in early gestation, cong. paraplegia Functional changes on supraspinal level largely unknown Somatotopic organization of M1 in MMC? Hypothesis: normal organization above level, abnormal below Q1: activation of cortical lower limb repr. in motor imagery? Q2: neuroplastic changes? Cortical body representations shifted

Patients & Methods 10 right handed MMC patients, thoracic level, ASIA A Whole brain BOLD-fMRI, 1.5 T & 3.0 T (n = 5), shunt valves 14 right handed volunteers, age matched (3.0 T) Motor fMRI (EM, IM), foot (F), fingers (H), tongue (T) Structural MRI 3D T1 (MPRAGE, sagittal, 1 mm 3 isovoxel) Standardized evaluation, individual data: BrainVoyager ® Anatomo-functional correlation (6 morph.., 6 funct. landmarks) Spatial normalization (euclidean coordinates: x, y, z) Statistics: Wilcoxon Mann Whitney U-test, sign. p < 0.05 Primary Motor Cortex in Congenital Paraplegia

M1 Somatotopy (Volunteers) Primary Motor Cortex in Congenital Paraplegia FootHandTongueCortical representations

M1 Somatotopy (Patients) Primary Motor Cortex in Congenital Paraplegia Normal tongue representation

M1 Somatotopy (Patients) Primary Motor Cortex in Congenital Paraplegia Normal hand representation

M1 Somatotopy (Patients) Primary Motor Cortex in Congenital Paraplegia Shifted foot representation, pa (y) > lat (x); 50% bilateral

M1 Activations in MMC Primary Motor Cortex in Congenital Paraplegia RH: x = 9.2 mm, y = 17.6 mm, z = 3.1 mm; LH: x = 9.0 mm, y = 11.8 mm, z = 2.8 mm * missing patients excluded, metal artefacts (shunt valves)

M1 Somatotopy (Patients) Primary Motor Cortex in Congenital Paraplegia Body representations in MMC: individual data

M1 Somatotopy (Patients & Volunteers) Primary Motor Cortex in Congenital Paraplegia Different body representations in M1: grouped data

Conclusion MMC patients activate M1 foot reps. in motor imagery M1 somatotopy is preserved in MMC Functional organization below level is altered (shifted reps.) Cave: normalization error in dysgenetic brain Functional organization above level is normal Some patients activate bilaterally (one sided imagery impossible?) Primary Motor Cortex in Congenital Paraplegia

Magnetically adjustable CSF-shunt Valves (3T) Akbar M., Stippich C., Aschoff A., New England Journal of Medicine 2006 MR-Safety / Phantomstudies

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