Delayed thalamic damage after stroke: discriminator for recovery success from functional loss in the cortex of the rat.
Strecker C, Justicia C, Ramos-Cabrer P, Weber R, Wiedermann D, Hoehn M, Sprenger C
Max-Planck-Institute for Neurological Research
Following MCAO in the rat, damages affecting thalamocortical projections can cause secondary neuronal degeneration in the thalamus, which may explain lack of activity in the S1 cortical areas. Repetitive fMRI, SSEPs and behavioural experiments were performed for 7 weeks after MCAO, finishing with histology. Only animals with permanent loss of BOLD response in the S1 showed gliosis and neuronal death in both the ventral-posteromedial (VPM) and the ventral-posterolateral (VPL) thalamic nuclei. In animals with transient BOLD loss (<3 weeks) only the VPM was affected. Secondary damages to thalamic regions can aggravate the functional outcome after stroke. Recurrence of BOLD will depend on the extension of this delayed damage.