Hyperechogenicity of the Thalamus and Basal Ganglia in Very Preterm Infants: Radiological Findings and Short-Term Neurological Outcome

Abstract

Cerebral ultrasound of preterm infants may show diffuse, bilateral, hyperechogenic “haze” over the thalami and basal ganglia (hyperechogenicity BGT). We explored whether this could be a pathological phenomenon. All cerebral ultrasound examinations performed in 2001 on infants < 35 weeks of age were reviewed. This resulted in a hyperechogenicity and non-hyperechogenicity group. The character of the hyperechogenicity BGT and the presence of concomitant brain lesions were noted. Detailed clinical and follow-up data from a selected group of infants < 32 weeks were reviewed and compared between the 2 groups. The incidence of hyperechogenicity BGT was 11 % (39/359) in infants < 35 weeks and 26 % (37/143) in infants < 32 weeks. Birth weight and gestational age were significantly lower and clinical course was more complicated in the hyperechogenicity group. Concomitant brain lesions were always present. In 12/39 infants with hyperechogenicity BGT, MRI (always performed for other reasons) was available, showing signal intensity changes in thalamic region in 5 infants. The neurological outcome at term was less favorable in the hyperechogenicity group, but similar at 1 year. Thus hyperechogenicity BGT mainly occurred in very small, sick infants and was always associated with cerebral pathology. MRI did not consistently show abnormalities in the thalamic region. It was not associated with a poorer outcome at 1 year.

Key words

Preterm infants - thalamus and basal ganglia - cerebral ultrasonography

References

• 1 Barkovich A J, Westmark K, Partridge C, Sola A, Ferriero D M. Perinatal asphyxia: MR findings in the first 10 days.  AJNR. 1995;  16 427-438
• 2 Barkovich A J, Sargent S K. Profound asphyxia in the premature infant: imaging findings.  AJNR. 1995;  16 1837-1846
• 3 Cioni G, Fazzi B, Ipata A E, Canapicchi R, Van Hof-Van Duin J. Correlation between cerebral visual impairment and magnetic resonance imaging in children with neonatal encephalopathy.  Dev Med Child Neurol. 1996;  38 120-132
• 4 De Vries L S, Regev R, Pennock J M, Wigglesworth J S, Dubowitz L M. Ultrasound evolution and later outcome of infants with periventricular echodensities.  Early Hum Dev. 1988;  16 225-233
• 5 De Vries L S, Dubowitz L M. Hemorrhagic and ischemic lesions of the perinatal brain.  Int J Technol Assess Health Care. 1991;  7 (Suppl 1) 99-105
• 6 De Vries L S, Smet M, Goemans N, Wilms G, Devlieger H, Casaer P. Unilateral thalamic haemorrhage in the pre-term and full-term newborn.  Neuropediatrics. 1992;  23 153-156
• 7 De Vries L S, Eken P, Dubowitz L MS. The spectrum of leukomalacia using cranial ultrasound.  Behav Brain Res. 1992;  49 1-6
• 8 De Vries L S, Groenendaal F, Eken P, Van Haastert I C, Rademaker K J, Meiners L C. Infarcts in the vascular distribution of the middle cerebral artery in preterm and full-term infants.  Neuropediatrics. 1997;  28 88-96
• 9 Flechsig P. Anatomie des menschlichen Gehirns und Rückenmarks auf myelogenetischer Grundlage. Leipzig; Thieme 1920
• 10 Jongmans M, Henderson S, De Vries L S, Dubowitz L. Duration of periventricular densities in preterm infants and neurological outcome at 6 years of age.  Arch Dis Child Fetal Neonatal Ed. 1993;  69 9-13
• 11 Jongmans M, Mercuri E, De Vries L, Dubowitz L, Henderson S E. Minor neurological signs and perceptual-motor difficulties in prematurely born children.  Arch Dis Child Fetal Neonatal Ed. 1997;  76 F9-F14
• 12 Krägeloh-Mann I, Helber A, Mader I, Staudt M, Wolff M, Groenendaal F. et al . Bilateral lesions of thalamus and basal ganglia: origin and outcome.  Dev Med Child Neurol. 2002;  44 477-484
• 13 Levene M I, Williams J L, Fawer C L. Ultrasound of the infant brain.  Clin Dev Med. 1985;  92 9-33
• 14 Levene M, Dowling S, Graham M, Fogelman K, Galton M, Phillips M. Impaired motor function (clumsiness) in 5-year-old children: correlation with neonatal ultrasound scans.  Arch Dis Child. 1992;  67 687-690
• 15 Levene M I. The asphyxiated newborn infant. Levene MI, Lilford RJ, Bennett MJ Fetal and Neonatal Neurology and Neurosurgery. New York; Churchill Livingstone 1995: 405-425
• 16 Mercuri E, Guzzetta A, Haataja L, Cowan F, Rutherford M, Counsell S. et al . Neonatal neurological examination in infants with hypoxic ischaemic encephalopathy: correlation with MRI findings.  Neuropediatrics. 1999;  30 83-89
• 17 Prechtl H FR, Beintema D. The Neurological Examination of the Full-Term Newborn Infant. London; S. I. M. P. with Heinemann Medical 1964
• 18 Rutherford M A, Pennock J M, Schwieso J E, Cowan F M, Dubowitz L M. Hypoxic ischaemic encephalopathy: early magnetic resonance imaging findings and their evolution.  Neuropediatrics. 1995;  26 183-191
• 19 Rutherford M, Pennock J, Schwieso J, Cowan F, Dubowitz L. Hypoxic-ischaemic encephalopathy: early and late magnetic resonance imaging findings in relation to outcome.  Arch Dis Child Fetal Neonatal Ed. 1996;  75 F145-F151
• 20 Sie L TL, Van der Knaap M S, Van Wezel-Meijler G, Taets van Amerongen A HM, Lafeber H N, Valk J. Early MR features of hypoxic-ischemic brain injury in neonates with periventricular densities on sonograms.  AJNR. 2000;  21 852-861
• 21 Touwen B CL. Neurological Development in Infancy. London; S. I. M. P. with Heinemann Medical 1976
• 22 Trounce J Q, Fawer C L, Punt J, Dodd K L, Fielder A R, Levene M I. Primary thalamic haemorrhage in the newborn: a new clinical entity.  Lancet. 1985;  26 190-192
• 23 Van der Knaap M S, Valk J. Myelination and retarded myelination. Van der Knaap MS, Valk J Magnetic Resonance of Myelin, Myelination, and Myelin Disorders. 2nd ed. Berlin; Springer-Verlag 1995: 31-52
• 24 Van Gelder-Hasker M R, Van Wezel-Meijler G, De Groot L, Van Geijn H P, De Vries J I. Peri- and intraventricular cerebral sonography in second- and third-trimester high-risk fetuses: a comparison with neonatal ultrasound and relation to neurological development.  Ultrasound Obstet Gynecol. 2003;  22 110-120
• 25 Van Wezel-Meijler G, Van der Knaap M S, Sie L TL, Oosting J, Taets van Amerongen A HM, Cranendonk A. et al . Magnetic resonance imaging of the brain in premature infants during the neonatal period. Normal phenomena and reflection of mild ultrasound abnormalities.  Neuropediatrics. 1998;  29 89-96
• 26 Van Wezel-Meijler G, Hummel T Z, Oosting J, De Groot L, Sie L TL, Huisman J. et al . Unilateral thalamic lesions in premature infants: risk factors and short-term prognosis.  Neuropediatrics. 1999;  30 300-306
• 27 Voit T, Lemburg P, Neuen E, Lumenta C, Stork W. Damage of thalamus and basal ganglia in asphyxiated full-term neonates.  Neuropediatrics. 1987;  18 176-181
• 28 Volpe J J. Intracranial hemorrhage: Germinal matrix-intraventricular hemorrhage of the premature infant. Volpe JJ Neurology of the Newborn. Philadelphia; Saunders 1995: 403-463
• 29 Yakovlev P I, Lecours A R. The myelogenetic cycles of regional maturation of the brain. Minkowski A Regional Development of the Brain in Early Life. Oxford; Blackwell Scientific 1967: 3-70