Cranial ultrasound in cerebral palsy

Abstract

Neurological injury underlying cerebral palsy (CP) typically occurs in the first month of life. At this age, cranial ultrasound is an ideal method for neurological imaging. Ultrasound is portable, can be performed at the bedside, and involves no radiation or sedation. Because it is usually readily available, it allows for multiple longitudinal assessments. Infants with neurological damage may have difficulty traveling for magnetic resonance (MR), and ultrasound may provide the only opportunity to visualize the acute abnormality, which may be less apparent over time on a later MR. Premature infants are at the highest risk for neurological injury leading to CP. The most common injury is intracranial hemorrhage of prematurity, typically centered in the subependymal layer at the germinal matrix. A four-stage grading system is typically used, with the more severe grades III and IV being associated with CP. Ischemic injury of prematurity can also lead to CP. In premature infants, global cerebral anoxia results in a characteristic pattern of injury known as periventricular leukomalacia. Global hypoxic-ischemic injury in term infants has a different pattern, affecting predominantly basal ganglia, corpus callosum, and watershed territories of the cerebral arteries. Hemorrhage in the term infant most commonly involves the choroid plexus, distinct from the germinal matrix hemorrhage seen in premature infants. Less commonly, CP may follow a perinatal infection or congenital developmental abnormality in either term or preterm infants. These findings are more subtle by ultrasound, but detection can be improved with training. Ultrasound is a valuable tool in assessment of the neonatal injuries that frequently underlie CP.