Neurorehabilitation after neonatal intensive care: evidence and challenges

Abstract

Neonatologists and paediatric providers of developmental care have documented poor neurodevelopmental outcomes of infants who have received neonatal intensive care due to prematurity, perinatal neurological insults such as asphyxia or congenital anomalies such as congenital heart disease. In parallel, developmental specialists have researched treatment options in these high-risk children. The goal of this review is connect the main categories of poor outcomes (sensory and motor function, cognition, communication, behaviour) studied by neonatal intensive care follow-up specialists to the research focused on improving these outcomes. We summarise challenges in designing diagnostic and interventional approaches in infants <2 years of age and review the evidence for existing therapies and future treatments aimed at improving functionality.

Keywords: Neonatology; Neurodevelopment; Neurodisability; Rehabilitation.

Figure 1

Building blocks of neurodevelopment in neonatal intensive care unit graduates. The neonatal brain is subject to multiple influences during initial critical windows of development of basic pathways. Some of these phases are independent of experience but affected by injury, plasticity and interruption or resumption of normal developmental sequences. Establishment of complex interconnections within and between the sensory and motor systems occurs at critical times during the maturation process and is dependent on experience, and therefore influenced by environmental conditions. The establishment of higher order processes (cognition, communication, behaviour) requires connections between cortical and subcortical areas, as well as among widely distributed functional networks (attention, receptive language, expressive language). These networks in infancy are built upon the information provided by direct sensory experience of the environment as well as indirect feedback from sensory–motor interactions). All higher processes are tightly interconnected and deficits rarely occur in isolation. Throughout neurodevelopment, maturation and experiences shape the construction and function of all systems. In addition to their contributions to the substrate of brain development, prematurity and growth/nutritional conditions may act by altering the maturation process through complications and deficiencies.

Figure 2

Example of newborn with sensorineural hearing loss due to perinatal hypoxic-ischemic encephalopathy diagnosed early using auditory brainstem response measurements and outcome with and without neurorehabilitation. (A) If hearing impairment is undiagnosed or untreated in the first 12–18 months, the resulting loss of auditory processing can lead to receptive and expressive language impairments. Later, communication impairments can lead to internalising behaviours related to social and emotional isolation, precursors of anxiety and depression. (B) Early diagnosis of hearing impairment followed by aggressive neurorehabilitation has a large downstream effect, preventing the arrest of neurodevelopment and facilitating functional adaptations. Early cochlear implant placement provides neural stimulation to the cochlear nerve and auditory cortex. Combined with speech language therapy (behavioural training), improved auditory processing allows the development of receptive and expressive language. Communication facilitates learning and social–emotional interactions, promoting the development of adaptive behaviours. ABR, auditory brainstem response; CBCL, Child Behavior Checklist.