The thalamus and basal ganglia are smaller in children with epilepsy after perinatal stroke

Abstract

Background: Epilepsy is one of the most serious consequences of perinatal stroke. Epilepsy itself has been proposed as a risk factor for impaired cognitive, language, and behavioral functioning. It is still unclear which children develop epilepsy after perinatal stroke. The current study aimed to evaluate the volume of the thalamus and the basal ganglia in children after perinatal stroke in relation to poststroke epilepsy.

Methods: The follow-up study included 29 children with perinatal arterial ischemic stroke (AIS), 33 children with presumed periventricular venous infarction (PVI), and 46 age- and sex-matched healthy controls. Magnetic resonance imaging was performed in children between the ages of 4 and 18 years, and volumetric analysis by segmentation was used to evaluate the size of the thalamus, caudate nucleus, putamen, globus pallidus, hippocampus, amygdala, and nucleus accumbens.

Results: During a median follow-up time of 12.8 years [interquartile range (IQR): 10.8-17.3] in the AIS group and 12.5 years (IQR: 9.3-14.8) in the PVI group (p = 0.32), epilepsy developed in 10 children (34.5%) with AIS and in 4 (12.1%) children with PVI, p = 0.036 [odds ratio (OR) = 3.8, 95%, confidence interval (CI): 1.04-14]. Epilepsy and interictal epileptiform discharges (IEDs) without clinical seizures were more often expressed in children with AIS (n = 16, 55%) than in children with PVI (n = 7, 21.2%), p = 0.0057 (OR = 3.8 95% CI: 1.04-14). In the AIS group, the ipsilesional and contralesional thalamus, ipsilesional caudate nucleus, and nucleus accumbens were significantly smaller in children with epilepsy compared to children without epilepsy. In the PVI group, the ipsilesional thalamus, caudate nucleus, and nucleus accumbens were smaller in the pooled group of epilepsy plus IED alone compared to children without epilepsy.

Conclusion: In children with AIS, epilepsy or IED occurred more often compared to children with PVI. Both patients with AIS and PVI with severe damage to the basal ganglia and the thalamus have a higher risk of developing poststroke epilepsy and should be monitored more closely throughout childhood to initiate timely antiseizure medication and rehabilitation.

Keywords: basal ganglia; epilepsy; interictal epileptiform discharges; ischemic perinatal stroke; thalamus.

Figure 1

Patient selection.

Figure 2

Volume of the normalized thalamus in the AIS and PVI subgroups and in the control group. Pairwise comparisons were conducted using the Benjamini–Hochberg method, and only the p-values that are below the significance threshold of the adjusted false discovery rate are significant and presented in the figure.

Figure 3

Individual MRI findings in children with perinatal stroke. Basal ganglia are marked with an asterisk, and the thalamus is marked with an arrow. (A) A girl at age 5 with neonatal AIS, right-side proximal middle cerebral artery stroke, and epilepsy. Axial T1-weighted MRI image shows the ipsilesional small size of the basal ganglia and thalamus. (B) A boy at age 14 with neonatal AIS and left-side proximal middle cerebral artery stroke, and IED. Axial T1-weighted MRI image shows the ipsilesional small size of the basal ganglia and thalamus. (C, D) A girl at age 16 with neonatal AIS and left-side anterior trunk of middle cerebral artery stroke without epilepsy. Axial PROPELLER T2-weighted MRI image shows the ipsilesional normal size of the basal ganglia and thalamus. (E) A girl at age 17 with large right-side presumed PVI and epilepsy. Axial T1-weighted MRI image shows right-side periventricular damage and ipsilesional small size of the basal ganglia and thalamus. (F, G) A girl at age 7 with right-side presumed PVI and IED. Axial T1-weighted MRI image shows right-side periventricular damage and ipsilesional small size of the thalamus and normal basal ganglia. (H, I) A girl at age 11 with left-side presumed PVI and without epilepsy. Axial FLAIR MRI image shows left-side periventricular damage and ipsilesional minimally smaller size of the thalamus and normal basal ganglia.