[Reorganization of the corticospinal tract and thalamocortical projections in children with sequelae of severe traumatic brain injury].

Objective: To associate the clinical recovery of locomotor function with the functional and structural viability of corticospinal and thalamocortical projections in children in the intermediate and long-term periods after severe traumatic brain injury (TBI).

Materials and methods: The study included 11 children (7 in the intermediate and 4 in the long-term periods of severe TBI). Clinical status was assessed based on muscle strength and tone testing in the distal parts of the hands (using the Muscle Strength Scale and the Modified Ashworth Spasticity Scale) and the classification system for large motor functions. Electrophysiological methods include somatosensory evoked potentials during median nerve stimulation, diagnostic single-pulse transcranial magnetic stimulation (sTMS), and routine electroencephalography with functional tests. Neuroimaging included magnetic resonance tractography from the primary motor cortex and supplementary motor area.

Results: Preliminary data indicate the complexity of assessing the dependence of motor deficit (K-coefficient) on the preservation of corticospinal projections from the primary motor cortex and supplementary motor area and amplitudes of motor evoked potentials in the intermediate period; however, they suggest a correlation between these parameters in the long-term period after severe TBI in children.

Conclusion: Based on the presented cases, preservation of corticospinal projections according to neuroimaging data and motor evoked potentials according to sTMS are unreliable predictors of locomotor function recovery-their predictive value increases in the long-term after TBI upon completion of structural and functional remodeling.