Study design: Prospective clinical study.
Background: The aim of the study was to investigate cortical reorganisation after traumatic spinal cord injury (TSCI) using functional magnetic resonance imaging (fMRI).
Setting: Tartu University Hospital, Tartu, Estonia.
Methods: We studied six right-handed tetraplegic TSCI patients at 1, 3 and 12 months after the injury and 12 age- and gender-matched healthy controls. Individuals performed simple test-rest cycles of flexion/extension of the right-hand fingers and flexion/extension of the right ankle during fMRI. The volumes of activation (VOA), maximum t-values, centres of gravity (COG) and weighted laterality indexes were calculated.
Results: There was no recovery of neurologic function in three patients and, according to the American Spinal Injury Association (ASIA) Impairment Scale the remaining three recovered. A positive correlation between the VOA in the primary motor cortex and the ASIA impairment scale (1 month: r=0.82, P=0.002; 3 Month: r=0.63, P=0.03; 12 Month: r=0.23, P=0.52) was found. The study also revealed a pattern of cortical activation that was increased among the patients who recovered (in Brodmann area 4 (BA 4), P=0.06; BA 1-2-3-5, P=0.08; BA 6, P=0.05). During the hand task there was an expansion of COG laterally, anteriorly and inferiorly among the patients who recovered. During the hand movement the cortical activation was less lateralised among the patients compared with the controls (P<0.05).
Conclusion: Our study has found broadening of cortical activation and shift of COG during the first year after TSCI, depending on the recovery.