Primitive reflexes are reflex actions originating in the central nervous system that are exhibited by normal infants, but not neurologically intact adults, in response to particular stimuli. These reflexes are suppressed by the development of the frontal lobes as a child transitions normally into child development.[1] These primitive reflexes are also called infantile, infant or newborn reflexes.
Older children and adults with atypical neurology (e.g., people with cerebral palsy) may retain these reflexes and primitive reflexes may reappear in adults. Reappearance may be attributed to certain neurological conditions including dementia (especially in a rare set of diseases called frontotemporal degenerations), traumatic lesions, and strokes.[2][3] An individual with cerebral palsy and typical intelligence can learn to suppress these reflexes, but the reflex might resurface under certain conditions (i.e., during extreme startle reaction). Reflexes may also be limited to those areas affected by the atypical neurology, (i.e., individuals with cerebral palsy that only affects their legs retaining the Babinski reflex but having normal speech); for those individuals with hemiplegia, the reflex may be seen in the foot on the affected side only.
Primitive reflexes are primarily tested with suspected brain injury or some dementias such as Parkinson's disease for the purpose of assessing frontal lobe functioning. If they are not being suppressed properly they are called frontal release signs. Atypical primitive reflexes are also being researched as potential early indicators of autistic spectrum disorders.[4]
Primitive reflexes are mediated by extrapyramidal functions, many of which are already present at birth. They are lost as the pyramidal tracts gain functionality with progressive myelination. They may reappear in adults or children with loss of function of the pyramidal system due to a variety of reasons. However, with the advent of Amiel Tison method of neurological assessment, the importance of assessment of such reflexes in the pediatric population has come down.[5][6][7]
- ^ "Primitive & Postural Reflexes" (php). Retrieved 2008-10-23.
- ^ Rauch, Daniel (2006-10-05). "Infantile reflexes on MedLinePlus". MedlinePlus. Retrieved 2007-10-11.
- ^ Schott, JM; Rossor, MN (2003). "The grasp and other primitive reflexes". J. Neurol. Neurosurg. Psychiatry. 74 (5): 558–60. doi:10.1136/jnnp.74.5.558. PMC 1738455. PMID 12700289.
- ^ Teitelbaum, O.; Benton, T.; Shah, P. K.; Prince, A.; Kelly, J. L.; Teitelbaum, P. (2004). "Eshkol-Wachman movement notation in diagnosis: the early detection of Asperger's syndrome". Proc. Natl. Acad. Sci. U.S.A. 101 (32): 11909–14. Bibcode:2004PNAS..10111909T. doi:10.1073/pnas.0403919101. PMC 511073. PMID 15282371.
- ^ Amiel-Tison C, Grenier A. Neurological Assessment during first year of life. New York. Oxford University Press, 1986; 46-94.
- ^ Paro-Panjan, D; Neubauer, D; Kodric, J; Bratanic, B (Jan 2005). "Amiel-Tison Neurological Assessment at term age: clinical application, correlation with other methods, and outcome at 12 to 15 months". Developmental Medicine and Child Neurology. 47 (1): 19–26. doi:10.1111/j.1469-8749.2005.tb01035.x. PMID 15686285. S2CID 20486547.
- ^ Leroux, BG; N'guyen The Tich, S; Branger, B; Gascoin, G; Rouger, V; Berlie, I; Montcho, Y; Ancel, PY; Rozé, JC; Flamant, C (22 February 2013). "Neurological assessment of preterm infants for predicting neuromotor status at 2 years: results from the LIFT cohort". BMJ Open. 3 (2): e002431. doi:10.1136/bmjopen-2012-002431. PMC 3586154. PMID 23435797.
