What is it?
Primitive reflexes are automatic patterns of movements originating in-utero and fully present at birth for neurological growth and development of specific functions (1). While necessary for the survival and growth of infants, as the brain develops and matures during the first year of postnatal life, these once automatic reactions should transition from brainstem reflex responses to cortically controlled responses and “disappear,” allowing the development of purposeful and volitional motor movements (2-4).
Why is it important?
Each reflex is a specific and adequate response of the central nervous system (CNS) to one or more stimuli used to process sensory information, such as auditory, taste, tactile, visual, vestibular, proprioceptive, and olfactory resulting in specific and adequate motor, postural, glandular, pupillary, or tympanic membrane reactions (5). Because the integration of primitive reflexes reflect a maturation process needed to develop a higher, more controlled sensory-motor system, dysfunction or abnormalities in the process in degree or rate may lead to significant problems in the development of motor functioning (5) and the attainment of gross-motor milestones (6,7).
More commonly known primitive reflexes include the asymmetrical tonic neck (ATNR), symmetrical tonic neck (STNR), tonic labyrinthine (TLR), plantar, palmar, rooting, and spinal Galant reflexes. If retained, the consequences could present as difficulty reading or learning to read, spinal deformities, poor hand-eye-coordination, difficulty focusing, learning or swimming, poor balance, disorientation or emotional dysregulation (8-11) as commonly seen in many neurodevelopmental and congenital disorders (1-14).
How does it work?
It is important to note that although the presence of these reflexes are meant to disappear, the areas of the brainstem where these automatic responses are integrated do not disappear, as well. Instead, as an infant learns more complex tasks, these brainstem centers transfer the greatest part of their function to cortical centers, aiding in more controlled, adapted and intentional movement patterns. Tight associations are subsequently made between the lower brainstem centers and the higher cortical centers as these unconditioned reflexes are conditioned and subordinated under conscious control. Because tight associations are made between the older, primitive, way of responding the environment and a newer, consciously controlled way, when the cortex is poorly functioning due to illness, injury, shock, stress, trauma, etc., the brain relies on sub-cortical functions and the presence of these reflexes are once again seen and not under conscious control (12-14).
How does it help?
The presence of a primitive reflex, whether you are a child or adult, doesn’t suggest that you have a neurological disorder. But when these reflex functions are pathological, dysfunctional, immature, or lacks integration with higher cortical centers, rehabilitation to re-route, re-connect, and re-build neural pathways is needed to facilitate neurological maturation (15,16).