Ipsilesional volume loss of basal ganglia and thalamus is associated with poor hand function after ischemic perinatal stroke.

BACKGROUND: Perinatal stroke (PS) is the leading cause of hemiparetic cerebral palsy (CP). Involvement of the corticospinal tract on neonatal magnetic resonance imaging (MRI) is predictive of motor outcome in patients with hemiparetic CP. However, early MRI is not available in patients with delayed presentation of PS and prediction of hemiparesis severity remains a challenge. AIMS: To evaluate the volumes of the basal ganglia, amygdala, thalamus, and hippocampus following perinatal ischemic stroke in relation to hand motor function in children with a history of PS and to compare the volumes of subcortical structures in children with PS and in healthy controls. METHODS: Term born PS children with arterial ischemic stroke (AIS) (n = 16) and with periventricular venous infarction (PVI) (n = 18) were recruited from the Estonian Pediatric Stroke Database. MRI was accuired during childhood (4-18 years) and the volumes of the basal ganglia, thalamus, amygdala and hippocampus were calculated. The results of stroke patients were compared to the results of 42 age- and sex-matched healthy controls. Affected hand function was evaluated by Assisting Hand Assessment (AHA) and classified by the Manual Ability Classification System (MACS). RESULTS: Compared to the control group, children with AIS had smaller volumes of the ipsi- and contralesional thalami, ipsilesional globus pallidus, nucleus accumbens and hippocampus (p < 0.005). Affected hand function in children with AIS was correlated with smaller ipsilesional thalamus, putamen, globus pallidus, hippocampus, amygdala and contralesional amygdala (r > 0.5; p < 0.05) and larger volume of the contralesional putamen and hippocampus (r < - 0.5; p < 0.05). In children with PVI, size of the ipsilesional caudate nucleus, globus pallidus, thalamus (p ≤ 0.001) and hippocampus (p < 0.03) was smaller compared to controls. Smaller volume of the ipsi- and contralesional thalami and ipsilesional caudate nucleus was correlated with affected hand function (r > 0.55; p < 0.05) in children with PVI. CONCLUSIONS: Smaller volume of ipsilesional thalamus was associated with poor affected hand function regardless of the perinatal stroke subtype. The pattern of correlation between hand function and volume differences in the other subcortical structures varied between children with PVI and AIS. Evaluation of subcortical structures is important in predicting motor outcome following perinatal stroke.

Resting-State Functional Connectivity and Cognitive Impairment in Children with Perinatal Stroke.

Perinatal stroke is a leading cause of congenital hemiparesis and neurocognitive deficits in children. Dysfunctions in the large-scale resting-state functional networks may underlie cognitive and behavioral disability in these children. We studied resting-state functional connectivity in patients with perinatal stroke collected from the Estonian Pediatric Stroke Database. Neurodevelopment of children was assessed by the Pediatric Stroke Outcome Measurement and the Kaufman Assessment Battery. The study included 36 children (age range 7.6-17.9 years): 10 with periventricular venous infarction (PVI), 7 with arterial ischemic stroke (AIS), and 19 controls. There were no differences in severity of hemiparesis between the PVI and AIS groups. A significant increase in default mode network connectivity (FDR 0.1) and lower cognitive functions (p < 0.05) were found in children with AIS compared to the controls and the PVI group. The children with PVI had no significant differences in the resting-state networks compared to the controls and their cognitive functions were normal. Our findings demonstrate impairment in cognitive functions and neural network profile in hemiparetic children with AIS compared to children with PVI and controls. Changes in the resting-state networks found in children with AIS could possibly serve as the underlying derangements of cognitive brain functions in these children.

Vascular syndrome predicts the development and course of epilepsy after perinatal stroke.

OBJECTIVE: Epilepsy develops in one third of the patients after perinatal stroke. It is still unclear which vascular syndrome of ischemic stroke carries higher risk of epilepsy. The aim of the current study was to evaluate the risk of epilepsy according to the vascular syndrome of perinatal stroke. METHODS: The study included 39 children with perinatal arterial ischemic stroke (13 with anterior or posterior trunk of the distal middle cerebral artery occlusion, 23 with proximal or distal M1 middle cerebral artery occlusion and three with lenticulostriate arteria infarction), and 44 children with presumed perinatal venous infarction. Magnetic resonance imaging obtained at the chronic stage was used to evaluate the vascular syndrome of stroke. RESULTS: The median follow-up time was 15.1 years (95% CI: 12.4-16.5 years), epilepsy developed in 19/83 (22.9%) patients. The cumulative probability to be without epilepsy at 15 years was 75.4% (95% CI: 65.8-86.4). The probability of having epilepsy was higher in the group of proximal or distal M1 artery occlusion compared to patients with periventricular venous infarction (HR 7.2, 95% CI: 2.5-26, p = .0007). Patients with periventricular venous infarction had significantly more often status epilepticus or spike-wave activation in sleep ≥85% of it compared to patients with anterior or posterior trunk of the distal middle cerebral artery occlusion (OR = 81; 95% CI: 1.3-5046, p = .029). SIGNIFICANCE: The emphasis of this study is placed on classifying the vascular syndrome of perinatal stroke and on the targeted follow-up of patients for epilepsy until young adulthood. The risk for having epilepsy after perinatal stroke is the highest in children with proximal or distal M1 middle cerebral artery occlusion. Patients with periventricular venous infarction have a more severe course of epilepsy.

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

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.

Language lateralization and outcome in perinatal stroke patients with different vascular types.

Perinatal stroke affects child's language development and can change language lateralization. Language generation and comprehension tasks in functional magnetic resonance imaging were used to determine language lateralization in term born children with perinatal left-side arterial ischemic stroke (AIS) (n = 9, mean age (SD) 13.4 (3.1) y.) and periventricular venous infarction (PVI) (n = 12, 11.8 (2.8) y.), and in healthy right-handed controls (n = 30, 11.6 (2.6) y.). Lateralization index was calculated for the Broca and Wernicke areas and correlated with language and cognitive outcomes measured by the Kaufman Assessment Battery for Children II ed. Language outcome in children with perinatal stroke is poorer compared to healthy controls. Children with small AIS lesions and most children with PVI showed left-side language activation. Most children with large AIS lesions and one child with large PVI had language activation reorganized to the right hemisphere. Language reorganization to the unlesioned right hemisphere did not ensure normal language outcome.