Martínez HR, González-Garza MT, Moreno-Cuevas JE, Caro-Osorio E, Gil-Valadez A, Ocañas CEE, Marioni SS and Hernandez-Torre M
Background and Purpose: Amyotrophic lateral sclerosis (ALS) is characterized by the selective death of motor
neurons. Cortical neuron loss is associated with axonal degeneration along specific white matter tracts. Fractional
anisotropy (FA) determined by Magnetic Resonance (MR) might detect integrity or changes in brain white matter
pathways. This study was aimed to analyze pyramidal tract changes in ALS patients submitted to stem cell
transplantation into the frontal motor cortices.
Patients and Methods: Fourteen patients with definite ALS were included. After signing their informed consent,
the patients underwent magnetic resonance imaging (MRI). The pyramidal tract (PT) from the corona radiata to
medulla oblongata was evaluated by quantitative voxel-wise analysis, including FA and diffusion tensor tractography
derived from MR diffusion tensor imaging (MR-DTI) at baseline and 6 months after CD 133+ stem cells
transplantation into the frontal motor cortices. FA changes were analyzed with the Tract-Based Spatial Statistics
software (FMRIB Software Library, Oxford University). Statistical analyzes among FA before and after stem cells
transplantation were performed using the SPSS, v.17.
Results: Improvement in FA was observed in the PT of the whole group when compared at baseline with 6
months after stem cell transplantation (p= 0.05). FA significative changes were observed in the PT at the corona
radiata (p= 0.05) and internal capsule regions (p= 0.03). FA changes were observed in the PT at the mesencephalic
and bulbar regions. However, they were not statistically significant.
Conclusions: FA positive changes suggest recovery of the PT in ALS subjects after stem cells transplantation.
These changes could possible be explained not only by cell replacement but also by modifications of the
extracellular motor neuronal environment, through trophic and neuroprotective effects of stem cells.