Epilepsy in children with periventricular leukomalacia

Objective

We aimed to analyze the development of epilepsy in a patient group with periventricular leukomalacia followed at a tertiary pediatric neurology center.

Patients and methods

The study included 108 children aged between 2 and 8 years with radiologically proven periventricular leukomalacia who had been regularly observed at the Istanbul University, Istanbul Faculty of Medicine, Department of Pediatrics, Pediatric Neurology outpatient clinic between January 2006 and December 2011.

Results

Neonatal seizures were reported in 22 patients (20.3%), 14 of whom developed epilepsy. A significant correlation was found between neonatal seizures and prematurity and newborn asphyxia (p = 0.013 and p = 0.010, respectively). Epilepsy developed in 35 patients (32.4%), history of neonatal seizures and more severe loss of white matter, periventricular hyperintensity and corpus callosum involvement were found to be correlated with epilepsy (p = 0.001, p = 0.004, p = 0.016, and p = 0.004, respectively). The most common seizure pattern observed was generalized tonic clonic seizures (n = 13) and complex partial seizures (n = 11). Those with focal EEG findings had a significantly better neurodevelopmental and cognitive level than those with multifocal/generalized EEG findings (p = 0.024). Seizures continued with varying frequency in 14 epileptic patients (40%) despite antiepileptic treatment.

Conclusion

Almost a third of patients with periventricular leukomalacia develop epilepsy that can be intractable in substantial part. Neonatal seizures and severe MRI findings are important clues that can indicate the development of epilepsy in these patients.     

Differences between periventricular hemorrhagic infarction and periventricular leukomalacia

Purpose: To clarify the differences between infants with periventricular hemorrhagic infarction (PVHI) and those with periventricular leukomalacia (PVL). Methods: We retrospectively evaluated the clinical features, ultrasonography, and electroencephalogram (EEG) findings in 22 preterm infants with PVHI and 49 with PVL. EEG and cranial ultrasonography were serially performed in all participants starting immediately after birth. Acute and chronic stage EEG abnormalities were evaluated separately. Results: Gestational age and birth weight were significantly lower in infants with PVHI than those with PVL. EEGs were normal in the majority of infants with PVHI on days 1–2. However, EEG abnormalities appeared after ultrasonography abnormalities. The majority of infants with PVL showed acute-stage EEG abnormalities on days 1–2. The rate of infants with acute-stage EEG abnormalities decreased with age, whereas the rate of infants with chronic-stage EEG abnormalities increased with age. Normal EEG before ultrasonography abnormalities was more common in infants with PVHI than in those with PVL. However, deterioration of acute-stage EEG abnormalities was more frequent in infants with PVHI than in those with PVL. Conclusions: PVHI was presumed to cause mostly postnatal injury, whereas PVL was presumed to cause mostly pre-or perinatal injury.     

Visual-perceptual impairment in children with periventricular leukomalacia

We set out to define visuo-perceptual impairment related to periventricular leukomalacia (PVL) using the Developmental Test of Visual Perception (DTVP). Correlations were sought between visual–perceptual deficits and DTVP profile and neuroradiological and neurophthalmological findings.

The DTVP was administered to 20 children (m/f: 10/10), aged between 5 and 8 years (mean: 6.95 years), presenting with: spastic diplegia; PVL documented by brain MRI; normal or mildly impaired visual acuity; mild-moderate upper limb functional impairment.

The mean General Visual–Perceptual Quotient was impaired, showing a great variability among the patients. Despite this, an uneven DTPV profile, characterised by a significant difference between the VMIQ and the Non-Motor Visual–Perceptual Quotient (P<0.001), and a poor result on the Closure subtest (identification of whole figures from incomplete visual information) was observed in all the subjects. This profile reflects a deficit in eye–hand coordination and in praxic-constructional abilities and could be the expression of malfunctioning of the occipital–parietal pathway of visual integration, the so-called ‘dorsal stream,’ a hypothesis reinforced by the emergence of a statistically significant correlation between the neuroradiological data and the presence of visual–perceptual impairment.     

Mild oliguria in preterm infants who later developed periventricular leukomalacia

The aim of this study is to determine whether or not renal involvement was present during the early neonatal period in preterm infants with PVL. We conducted a case-control study. The following items were evaluated; urine output, serum levels of sodium (Na), potassium (K), chloride (Cl), urea nitrogen (UN), and creatinine (Cr). The factors that could influence the urine output were also compared between the PVL and the control group. The mean urine output during the first 24h in the PVL group was 19.8ml/kg/day, and was significantly lower than in the control group (28.8ml/kg/day, p<0.05). The mean UN and Cr were not significantly different between the two groups. The minimal serum Na and Cl levels in the PVL group were significantly lower (128.3 and 94.3mEq/l) than those in the control group (134.8 and 100.7mEq/l, p<0.01 each). The maximal serum K level was significantly higher in the PVL group (6.47mEq/l) as compared to the control group (5.57mEq/l, p<0.05). There were no differences in any postnatal variables between the two groups. The preterm infants who later developed PVL had mild but significant oliguria during the first 24h of life. This suggests that preterm infants with PVL will have renal involvement immediately after birth.     

Relationship between serum lactate level and periventricular leukomalacia

In a case control study, we evaluated the serum lactate levels during the early days of life in preterm infants with periventricular leukomalacia (PVL), who were presumed to have suffered injury around birth. Thirteen infants diagnosed by ultrasonography as suffering from cystic PVL during the neonatal period and 26 normally developed infants matched by gestational age were enrolled in the study. The serum lactate level was measured repeatedly during the 72 h after birth. The mean serum lactate levels on admission were 2.95 ± 0.43 and 3.21 ± 0.29 mmol/L in the PVL and control groups, respectively. There was no statistically significant difference in the serum lactate level between the groups at any point during the first 72 h after birth. In conclusion, the serum lactate level was not elevated in preterm infants with PVL suggesting that the serum lactate level is not a useful predictor for the development of PVL in infants.     

Association of osteopontin with ischemic axonal death in periventricular leukomalacia

Osteopontin (OPN) is a bone matrix protein expressed my macrophages and related to the process of tissue calcification, and is also known to protect ischemic cells. To understand how OPN is involved in the process of ischemic axonal death in periventricular leukomalacia (PVL), we examined the immunoreactivity of OPN and ionized calcium binding adaptor molecule 1 (Iba1; microglia/ macrophage marker) at various stages of PVL. OPN immunoreactivity paralleled the number of Iba1-positive foam cells; a finding which suggests the production of OPN protein by foam cells. OPN immunoreactivity was not found in either normal white matter or acute PVL lesions, but was detected at the subacute and chronic stages in swollen and calcified axons bordering the ischemic zone. These findings suggest that OPN is closely associated with death of swollen axons at the periphery of the ischemic zone, regulating the presence or absence of calcification. Received: 20 January 1999 / Revised, accepted: 21 September 1999     

Physical condition of preterm infants with periventricular leukomalacia

The aim of this study is to determine the general condition of preterm infants with severe brain lesions and to compare it with that of normal preterm infants. The Score for Neonatal Acute Physiology (SNAP) was calculated in nine preterm infants with periventricular leukomalacia (PVL) whose initial electroencephalograms showed grade IV depression (PVL group), 18 preterm infants who did not require mechanical ventilation during the neonatal period, Spontaneous respiration (SR group), and 18 preterm infants who required mechanical ventilation (MV group). The sum of the following four items in SNAP was separately calculated and called the ‘lung score’: PaO₂, PaO₂/FiO₂ ratio, PaCO₂, and oxygenation index. In addition to SNAP, we evaluated some neonatal variables. SNAP is lower in the SR group than in the PVL (P<0.05) or MV (P<0.01) groups. The lung score was also lower in the SR group than in the PVL (P<0.05) or MV (P<0.01) groups. On the other hand, the residual score (SNAP minus lung score) was not significantly different among the three groups. The physical condition of infants with PVL was not poor, although respiratory distress was often observed.     

Frequency and prognostic significance of germinal matrix hemorrhage,periventricular leukomalacia,and pontosubicular necrosis in preterm neonates

Summary The occurrence of germinal matrix hemorrhage (GMH), periventricular leukomalacia (PVL), and pontosubicular necrosis (PSN) was evaluated in a material of 96 preterm infants. All cases were born at less than 38 weeks of gestation, and died within 30 days after birth. The frequency of GMH (50%) and PVL (24%) was within the range of previous observations, but the 59% occurrence of PSN argues against the assertion that intraventricular hemorrhage is the most common neuropathological finding in preterm neonates. However, different combinations of these injuries were found in more than half the cases affected. Of the 48 infants with GMH, 36 (75%) showed either PSN (19 cases), PVL (2 cases), or both lesions (15 cases), and the frequency of additional damage was related to the severity of hemorrhage. Thus, neonatal mortality may be more related to additional hypoxic/ischemic lesions than to the severity of hemorrhage per se. Clinical follow-up studies on subpopulations of preterm infants with and without GMH have shown no difference in frequency of mild and moderate psychomotoric deficiences. The 35% occurrence of PSN as a solitary lesion in the 48 cases without GMH was similar to the frequency of PSN as a single additional lesion in 48 cases with GMH (40%). This finding makes PSN and not GMH the most likely cause of at least less severe handicaps.     

The predictive value of electroencephalogram during early infancy for later development of West syndrome in infants with cystic periventricular leukomalacia

PURPOSE: The aim of this study was to elucidate a predictive value of electroencephalogram (EEG) during early infancy for later development of West syndrome (WS) in premature infants with cystic periventricular leukomalacia (PVL). METHODS: The subjects of this study were 19 infants with cystic PVL born between 1992 and 1996. EEGs were recorded at 3 months of corrected age (CA) in all of them. We divided these 19 infants into the following two groups; group A (n = 9), no paroxysmal discharge was recognized; and group B (n = 10), paroxysmal discharges were recognized. RESULTS: In none of the infants in group A did WS develop. Subsequent EEGs were normal in all infants in group A. WS developed in seven of 10 infants in group B. The occurrence of WS is significantly higher in group B than in group A. The mean age at the onset of WS was 6 months of CA. Paroxysmal discharges in infants in group B were observed as irregular spikes-and-waves and polyspikes-and-waves, mainly in bilateral parietooccipital areas. In seven of eight patients with severe MRI findings in group B, WS developed. CONCLUSIONS: Paroxysmal discharges during early infancy were correlated with later development of WS in infants with cystic PVL. The possibility of developing WS had increased in the children with the combination with EEG and MRI findings.     

Amplitude-integrated electroencephalogram 1 h after birth in a preterm infant with cystic periventricular leukomalacia

We report a preterm infant, who showed abnormal amplitude-integrated electroencephalogram (aEEG) findings 1 h after birth and later developed cystic periventricular leukomalacia (PVL). The patient was a girl with a gestational age of 29 weeks. She was delivered by emergency cesarean section because of placental abruption and intrauterine co-twin demise. Artificial ventilation and administration of surfactant were needed to treat respiratory distress syndrome. Her cardiovascular condition was stable with artificial ventilation. Cranial ultrasonography showed extended cystic PVL after 11 days of age. aEEG 1 h after birth showed a consistently inactive pattern that resolved completely 28 h after birth. The neurophysiological findings of this patient suggest that aEEG findings during the very early period after birth provide significant information for predicting PVL.     

Spontaneous movements in the supine position of healthy term infants and preterm infants with or without periventricular leukomalacia

Aim: The individual motor elements presumed to be essential for motor development were determined from spontaneous movements involving the entire body of normal term and preterm infants. Then, diagnostic items for motor abnormality in infants with periventricular leukomalacia (PVL) were investigated. Methods: Video recordings of 24 healthy term infants, 21 normal preterm infants (8 males, 13 females; median gestational age 30 weeks; median birth weight 1216 g) and 14 preterm infants with PVL (6 males, 8 females; median gestational age 30 weeks; median birth weight 1360 g) were analyzed. Results: In healthy term infants, predominant shoulder rotation was noticed until 1 month of age. After 2 months of age, isolated movements of the shoulder, elbow, hip, knee, and ankle frequently emerged. In preterm infants with PVL at the corrected age of 2 months, startle response and predominant shoulder rotation were more frequently seen and isolated neck, shoulder, elbow, hip, knee, and ankle movements were less frequently seen than in the normal preterm infants (Fisher’s exact test, p < 0.025). Interpretation: At 2 months of age, isolated movements evolve, and their failure to occur is suggested to be a useful sign for the diagnosis of cerebral motor disorders.     

Neuroprotective potential of erythropoietin and its derivative carbamylated erythropoietin in periventricular leukomalacia

Periventricular leukomalacia (PVL) is the predominant pathology in premature infants, characterized by prominent cerebral white matter injury, and commonly caused by hypoxia–ischemia and inflammation. Activated microglia trigger white matter damage and play a major role in the development of PVL. Erythropoietin (EPO) and its derivative carbamylated erythropoietin (CEPO) have been shown to be neuroprotective in several brain disease models. Here we investigated whether EPO and CEPO could provide protection in mouse models of PVL induced by hypoxia–ischemia or hypoxia–ischemia-inflammation. We administered EPO or CEPO to mice with PVL, and found that both EPO and CEPO treatments decreased microglia activation, oligodendrocyte damage and myelin depletion. We also noted improved performance in neurological function assays. Inhibited disease progression in PVL mice by EPO or CEPO treatment was associated with decreased poly-(ADP-ribose) polymerase-1 (PARP-1) activity. PARP-1 activity was increased dramatically in activated microglia in untreated mice with PVL. Furthermore, we demonstrated that the neuroprotective properties of EPO and CEPO were diminished after PARP-1 gene depletion. The therapeutic doses of EPO and CEPO used in this study did not interfere with normal oligodendrocyte maturation and myelination. Together, our data demonstrate that EPO and CEPO are neuroprotective in cerebral white matter injury via a novel microglial PARP-1 dependent mechanism, and hold promise as a future treatment for PVL and other hypoxic–ischemic/inflammatory white matter diseases.     

单用或联用UDP-糖、GDNF和美金刚对脑白质损伤大鼠长期预后的改善作用

目的 探讨单用和联用尿苷二磷酸葡萄糖(UDP-糖)、胶质细胞源性神经营养因子(GDNF)和美金刚对脑室周围白质软化(PVL)新生大鼠体格发育、学习记忆和肢体运动功能的远期影响. 方法 5日龄SD新生大鼠按照随机数字表法分为对照组、PVL组、UDP-糖组和UDP-糖+GDNF+美金刚组(简称三联药组).对照组大鼠仅游离右侧颈总动脉,不接扎和缺氧;PVL组大鼠结扎颈总动脉和缺氧;UDP-糖组大鼠在缺血缺氧后给予腹腔注射UDP-糖;三联药组大鼠在缺血缺氧后给予颅内注射GDNF,同时腹腔注射UDP-糖和美金刚.每组大鼠造模前后称重并记录睁眼日龄,在PVL造模后21d进行水迷宫和斜板测试,记录各组大鼠逃逸潜伏期、游泳距离及在不同倾斜角度下的斜板得分. 结果 PVL组在各时段的体质量及睁眼日龄均显著低于其他3组,四象限的平均逃逸潜伏期值和游泳距离数值均显著长于其他3组,在45°和50°斜板上的得分均显著低于其他3组,差异有统计学意义(P＜0.05);两个用药组间以及两个用药组分别和对照组间大鼠体质量、睁眼日龄、逃逸潜伏期值、游泳距离以及斜板评分的差异均无统计学意义(P＞0.05). 结论 单用UDP-糖或联用UDP-糖、GDNF和美金刚能明显改善脑白质损伤大鼠的长期预后,三联药组的改善作用略微更明显.     

High postnatal oxidative stress in neonatal cystic periventricular leukomalacia

Oxidative stress plays an important role in cystic periventricular leukomalacia (PVL). We performed a case-control study of preterm infants delivered at <35 weeks of gestation between January 2003 and December 2006. Patients were stratified into three groups, according to age at which cysts were initially identified: ?10 days old (early cystic PVL; n = 10), >10 days old (late cystic PVL; n = 12); and no cystic PVL (controls; n = 22). Serum total hydroperoxide, biological antioxidant potential and oxidative stress index (calculated as total hydroperoxide/biological antioxidant potential) were measured within 3 h after birth. Frequencies of preterm rupture of membrane and chorioamnionitis were significant higher in early cystic PVL than in late cystic PVL or controls. Duration of oxygen treatment and mechanical ventilation and frequency of apnea were significantly higher in late cystic PVL than in controls or early cystic PVL. Serum total hydroperoxide levels and oxidative stress index were significantly higher in early cystic PVL than in late cystic PVL or controls (p < 0.05, respectively). Postnatal duration until cyst identification displayed a significant negative correlation with oxidative stress index and total hydroperoxide level (r = −0.497, p < 0.05; r = −0.50, p < 0.05, respectively). These findings suggest that early onset of cystic PVL might be due to either antenatal or intrapartum factors, but late onset might be due to postnatal factors. In the pathophysiology and therapy of cystic PVL, oxidative stress and onset timing appear crucial. This is the first study to reveal that neonates experiencing much more oxidative stress at birth show earlier onset of cystic PVL.     

Nitrosative stress and inducible nitric oxide synthase expression in periventricular leukomalacia

Periventricular leukomalacia (PVL) is a lesion of the immature cerebral white matter in the perinatal period and associated predominantly with prematurity and cerebral ischemia/reperfusion as well as inflammation due to maternofetal infection. It consists of focal necrosis in the periventricular region and diffuse gliosis with microglial activation and premyelinating oligodendrocyte (pre-OL) injury in the surrounding white matter. We previously showed nitrotyrosine in pre-OLs in PVL, suggesting involvement of nitrosative stress in this disorder. Here we hypothesize that inducible nitric oxide synthase (iNOS) expression is increased in PVL relative to controls. Using immunocytochemistry in human archival tissue, the density of iNOS-expressing cells was determined in the cerebral white matter of 15 PVL cases [29–51 postconceptional (PC) weeks] and 16 control cases (20–144 PC weeks). Using a standardization score of 0–3, the density of iNOS-positive cells was significantly increased in the diffuse component of PVL (score of 1.8 ± 0.3) cases compared to controls (score of 0.7 ± 0.3) (P = 0.01). Intense iNOS expression occurred in reactive astrocytes in acute through chronic stages and in activated microglia primarily in the acute stage, suggesting an early role for microglial iNOS in PVL’s pathogenesis. This study supports an important role for iNOS-induced nitrosative stress in the reactive/inflammatory component of PVL.     

Correlation between clinical and ultrasound findings in preterm infants with cystic periventricular leukomalacia

Cystic periventricular Leukomalacia (CPVL), a hypoxic-ischemic lesion of the neonatal brain, which can now be diagnosed in life thanks to ultrasound brain scanning, is considered to be one of the main causes of cerebral palsy (CP), especially in preterm infants. The purpose of our study was to verify this assumption in a population of 337 of gestational age ≥32 weeks. The frequency of CPVL proved to be 5.4% for lesions with a diameter of ≥3 mm or 9.3% including those of smaller diameter. The development of CPVL infants was favorable in 29% and adverse in 71% of cases. In the latter cases neuromotor sequelae (CP in 62.5% and motor retardation in 8.5%) were accompanied by various other neuropsychic deficits. Prognosis depends on the site and size of the cysts, being harsher for posterior lesions and those exceeding 1 cm in diameter.

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Sommario La leucomalacia periventricolare cistica (CPVL), lesione ipossico-ischemica del cervello neonatale diagnosticabile in vita grazie all'ecografia cerebrale, viene considerata una delle principali cause della paralisi cerebrale infantile (P.C.I.), in particolare nei nati pretermine. Scopo della nostra ricerca è verificare tale ipotesi con una popolazione di 337 soggetti con E.G.≤32 settimane. L'incidenza della CPVL da noi rilevata è del 5.4% o del 9.3% considerando rispettivamente le forme con diametro ≥3 mm od anche quelle microcistiche (diametro <3 mm). L'evoluzione dei soggetti affetti da CPVL è favorevole nel 29% dei casi e sfavorevole nel 71%, con lo sviluppo di una sequela neuromotoria (PCI nel 62.5% e ritardo motorio nell'8.5%) variamente associata ad altri deficit neuropsichici. La prognosi è legata alla sede e alle dimensioni della cisti ed è tanto più grave per lesioni localizzate in sede posteriore od estese (di diametro ≥1 cm).

     

Using the Alberta Infant Motor Scale to early identify very low-birth-weight infants with cystic periventricular leukomalacia

We examined whether the Alberta Infant Motor Scale (AIMS) is able to identify very low-birth-weight (VLBW) preterm infants with cystic periventricular leukomalacia (PVL) as early as 6 months of corrected age. Longitudinal follow-up AIMS assessments were done at 6, 12, and 18 months old for 35 VLBW infants with cystic PVL (cPVL⁺), 70 VLBW infants without cystic PVL (cPVL⁻), and 76 term infants (healthy controls: HC). Corrected age was used for the preterm infants. The cPVL⁺ group had significantly lower prone, supine and sitting subscales at age 6, 12, and 18 months than the cPVL⁻ group (all p < 0.05). The cPVL⁻ group showed significantly lower supine, prone, sitting, and standing subscales than the HC group only at age 6 months. At age 6 months, the areas under the receiver operator curve used to discriminate the cPVL⁺ infants from cPVL⁻ infants were 0.82 ± 0.04 for prone, 0.93 ± 0.02 for supine, 0.83 ± 0.05 for sitting, and 0.62 ± 0.07 for standing. The AIMS may help early identify VLBW infants with cystic PVL at age 6 months old.     

Glutamate transporter EAAT2 expression is up-regulated in reactive astrocytes in human periventricular leukomalacia

The major neuropathological correlate of cerebral palsy in premature infants is periventricular leukomalacia (PVL), a disorder of the immature cerebral white matter. Cerebral ischemia leading to excitotoxicity is thought to be important in the pathogenesis of this disorder, implying a critical role for glutamate transporters, the major determinants of extracellular glutamate concentration. Previously, we found that EAAT2 expression is limited primarily to premyelinating oligodendrocytes early in development and is rarely observed in astrocytes until >40 weeks. In this study, we analyzed the expression of EAAT2 in cerebral white matter from PVL and control cases. Western blot analysis suggested an up-regulation of EAAT2 in PVL compared with control cases. Single- and double-label immunocytochemistry showed a significantly higher percentage of EAAT2-immunopositive astrocytes in PVL (51.8% +/- 5.6%) compared with control white matter (21.4% +/- 5.6%; P = 0.004). Macrophages in the necrotic foci in PVL also expressed EAAT2. Premyelinating oligodendrocytes in both PVL and control cases expressed EAAT2, without qualitative difference in expression. The previously unrecognized up-regulation of EAAT2 in reactive astrocytes and its presence in macrophages in PVL reported here may reflect a response to either hypoxic-ischemic injury or inflammation.     

经脑室植入神经干细胞在脑室周围白质软化新生大鼠脑内的迁移分化

背景：对新生动物进行脑内神经干细胞移植,所植入神经干细胞的增殖、迁移、分化、轴突形成以及髓鞘化等能力,均远远高于成年动物。 目的：对经脑室植入神经干细胞在脑室周围白质软化新生大鼠脑内的迁移分化功能进行观察,探讨神经干细胞移植对治疗早产儿脑室周围白质软化的可行性。 方法：2日龄脑室周围白质软化新生大鼠在建模后72 h进行经脑室神经干细胞移植。外源性神经干细胞用PKH26荧光素标记。脑立体定位仪下经脑室穿刺部位：前-后=1.5 mm,中线－外侧=-2 mm,深度=1.5 mm;移植细胞浓度为5×1010 L-1;移植总量为2 μL;移植速度0.5 μL/min。应用激光共聚焦显微镜分别对植入神经干细胞于植入后1,2,3,7,14,21 d进行动态观察。并分别进行各分化细胞的免疫荧光分析。 结果与结论：应用激光共聚焦显微镜对植入神经干细胞进行动态观察,证实经脑室植入的外源性神经干细胞在脑内具有良好的迁移能力,3 d内大部分移行至脑室周围区域,并分布在损伤严重部位。2周左右,神经干细胞在脑室周围区域主要分化为OL前体,部分分化为神经元及星形胶质细胞。提示经脑室神经干细胞移植对早产儿脑室周围白质软化具有很大的治疗潜力。     

Serial ultrasonographic observation of bilateral thalami in low birth weight infants with periventricular leukomalacia

Periventricular leukomalacia is a major form of neuropathology in preterm infants that is associated with adverse motor and cognitive outcomes. The volume of periventricular white matter and corpus callosum has been reported to be diminished in infants with PVL, and the degree of the volume loss is correlated with the severity of neurological impairment. The thalamic index was calculated from the length, height, width of the thalamus, and thalamic volume was calculated using the formula for an ovoid in 62 low birth weight infants with gestational ages of 24-35 weeks, 51 control infants (cerebral palsy, 1 case), and 11 infants diagnosed with PVL (cerebral palsy, 7 cases) at postnatal days 0-70. The indices of the right thalamus were lower in infants with PVL than in control infants from day 0 to day 70, and there were significant differences on days 21, 28, 35, 42, 49, 56, 63, and 70. The indices of the left thalamus were lower in infants with PVL than in control infants from day 0 to day 70, and there were significant differences on days 21, 28, 35, 42, 49, 56, 63, and 70. The results of the present study suggest that the volume of the thalami is reduced and that thalamic injury is associated with white matter lesions in infants with PVL.