Introduction

Perinatal stroke (PS) is the leading cause of hemiparetic cerebral palsy.(1) Diaschisis is characterized by a loss of function in one area of the brain following damage to a distant but connected brain region and may help explain motor system development following PS and define novel therapeutic targets for neuromodulation.(2-4) Here, we aimed to reveal how volumetric differences in the thalamus relate to motor function following PS.

Methods

Fifty-nine participants [20 arterial ischemic stroke (AIS); 11 periventricular venous infarction (PVI), 28 controls;] completed a 3T MRI protocol.  Anatomical T1 images were parcellated into 99 regions including both left and right thalami. Bilateral thalamic volumetric measures were compared to multiple, standardized, validated motor assessments (Assisting Hand Assessment, Melbourne Assessment).

Results

Both AIS and PVI groups had a significantly smaller ipsilesional thalamic volume compared to controls (p=0.001 and p=0.034, respectively). Ipsilesional thalamic volume was not associated with clinical motor outcomes. However, contralesional thalamic volume was significantly larger in AIS (but not PVI)  compared to controls (p=0.003) and was inversely correlated with all clinical motor assessments (all p<0.003).

Conclusion

Ipsilesional thalamic diaschisis occurs following perinatal stroke but is not strongly associated with motor outcome. Larger contralesional thalamic volume is associated with worse clinical motor function, potentially revealing maladaptive neuroplasticity following perinatal stroke. Our findings add a novel network node to emerging models of sensorimotor development following PS with implications for motor rehabilitation strategies.


References

1. Kirton A. Stroke. 2013;44:3265-3271.

2. Baron JC et al. Trans.Am.Neurol.Assoc. 1981;105:451-459.

3. Mah S et al. Stroke. 2013;44:2468-2474.

4. Craig et al. under review. (2018)