Primitive reflex is a reflex action derived from the central nervous system shown by a normal baby, but not a neurologically intact adult, in response to certain stimuli. These reflexes are suppressed by the development of the frontal lobe when the child transitions normally into a child's development. This primitive reflex is also called infantile , baby or the newborn reflex .
Older children and adults with atypical neurology (eg, people with cerebral palsy) can maintain these reflexes and these primitive reflexes may reappear in adults. Reappearance can be attributed to certain neurological conditions including dementia (especially on a rare set of diseases called frontotemporal degeneration), traumatic lesions, and strokes. A person with cerebral palsy and typical intelligence may learn to suppress this reflex, but the reflex may reappear under certain conditions (ie, during extreme shock reactions). Reflexes may also be limited to areas affected by atypical neurology, (ie, individuals with cerebral palsy who only affect their legs retain Babinski's reflexes but have normal speech); for people with hemiplegia, reflexes can be seen on the feet only on the affected side.
Primitive reflexes are primarily tested with suspicion of brain injury or some dementia such as Parkinson's disease for the purpose of assessing the function of the frontal lobes. If they are not properly pressed they are called a sign of a frontal release. Atypical primitive reflexes are also being investigated as an early warning sign of potential autistic spectrum disorders.
Primitive reflexes are mediated by extrapyramidal function, many of which are already present at birth. They disappear when the pyramidal tract gets functionality with progressive myelination. They may reappear in adults or children with loss of pyramidal system function for various reasons. However, with the emergence of the neurological assessment method of Amiel Tison, the importance of such reflex assessment in the pediatric population has fallen.
Video Primitive reflexes
Adaptive value of reflex
Reflexes vary in utility. Some reflexes have survival values ​​(such as rooting reflexes, which help breastfed babies find their nipples). Babies show a rooting reflex only when they are hungry and touched by others, not when they touch themselves. There are several reflexes that may help the baby's survival during human evolution (eg, Moro reflex). Other reflexes such as sucking and reaching help build a satisfying interaction between parent and baby. They can encourage parents to respond with love and affection, and feed their child more competently. In addition, it helps parents to entertain their babies while allowing the baby to control the pressure and the amount of stimulation they receive.
Maps Primitive reflexes
Moro reflex
These are sometimes referred to as shock reactions, shock responses, reflexes of reflexes or reflexes. This is better known as Moro or Moro reflex response after its discoverer, pediatrician Ernst Moro. Moro reflexes are present at birth, peak in the first month of life, and begin to disappear around the age of 2 months. This may happen if the baby's head suddenly shifts positions, the temperature changes abruptly, or they are struck by a sudden noise. The legs and heads extend while the arms jerk up and out with the palms up and the thumbs flexed. Soon the arms were put together and the hands clenched, and the baby cried loudly. Reflexes usually disappear at the age of three to four months, although it can last up to six months. The absence of bilateral reflexes may be related to damage to the central nervous system of infants, while unilateral absence may mean injury due to birth trauma (eg, clavicle fracture or injury to the brachial plexus). Erb paralysis or some other form of paralysis also sometimes appears in such cases. In the history of human evolution, Moro's reflex may have helped the baby attach to the mother when carried around. If the baby loses its balance, the reflex causes the baby to embrace her mother and regain her mother's mother.
Walk/step reflex
The walking or stepping reflexes are present at birth, although these young infants can not sustain their own weight. When the soles of their feet touch the flat surface, they will try to walk by placing one foot in front of the other. These reflexes disappear for about 5-6 months as the infant begins to walk after these reflexes disappear.
Rooting reflex
The rooting reflex is present at birth (28 weeks of age) and disappears around the age of four months, as it gradually comes under voluntary control. Rooting reflex helps in the action of breastfeeding. The newborn baby will turn his head in any direction that caresses his cheek or mouth, searching for objects by moving his head by continuing to lower the bow until the object is found. Once accustomed to responding in this way (if breastfed, approximately three weeks after birth), the baby will move directly to the object without searching.
Sucking reflex
Generally sucking reflexes for all mammals and present at birth. This is related to rooting and breastfeeding reflexes. This causes the child to instinctively suck whatever touches their palate, and simulates the way the child eats naturally. There are two stages of action:
- Expression : activated when the nipple is placed between the child's lips and touching their palate. They will instinctively push it between the tongue and the ceiling to remove the milk.
- Milking : The tongue moves from the areola to the nipple, persuading milk from the mother to be swallowed by the child.
Asymmetric tonic neck reflex
The asymmetric tonic neck reflex, also known as 'fence posture', comes at the age of one month and disappears for about four months. When the child's head is turned sideways, the arm on the side will straighten and the opposing arm will bend (sometimes the movement will be very smooth or slight). If the baby can not get out of this position or the reflex continues to be triggered beyond the age of six months, the child may have an upper motor neuron disorder. According to the researchers, neck tonic reflex is a precursor for hand/eye coordination of the baby. It also prepares the baby to reach out voluntarily.
Tonic symmetric neck reflex
Tonic neck symmetrical reflexes usually appear and develop around the age of 6-9 months and should be integrated around 12 months. When the child's head is bent forward, extending to the back of the neck, the upper limb will contract and the lower limb will expand. Conversely, when the head of the child is extended backwards, contracts behind the neck, the upper limb will lengthen and the lower extremity will contract. These reflexes are important to help a child push into their hands and knees, but can inhibit the actual creeping or crawling forward if not properly integrated. If these reflexes are maintained for more than 2-3 years, this may result, directly or indirectly, in various delays in physical and neurological development.
Palmar understands the reflex
Palmmar reflection holds up at birth and continues until the age of five or six months. When an object is placed in the baby's hand and caresses the palm of their hand, the fingers will close and they will hold it with a palmar handle. To better observe this reflex, in bed where the child can safely fall onto the pillow, offer the baby two opposite small fingers (because the index finger is usually too big for the baby to hold), and gradually lift. His grip may be able to support the child's weight, they can also unleash their grip suddenly and without warning. Backward motion can be induced by stroking the back or side of the hand.
Plantar Reflection
The plantar reflex is a normal reflex involving plantar flexion in the legs, which moves away from the shin and crinkles downward. The abnormal plantar reflex (aka Babinski Sign) occurs when the control of the upper motor neuron on the reflex circuits is disrupted. This results in dorsiflexion of the foot (the angle of the foot toward the shin, big toe curls). This also occurs in infants under c. 1 year, due to low myelination of the corticospinal tract. When this tract develops into an adult form, the reflex flexion circuit is inhibited by decreased corticospinal input, and the normal plantar reflex develops. Also known as Babinski reflex, this is a sign of neurological disorders in adults (eg, upper motor lesions).
Galant reflex
Galant reflexes, also known as Infantile reflex gall, are present at birth and fade between the ages of four and six months. When the skin along the back of the baby is stroked, the baby will swing toward the caressed side. If the reflex lasts for six months, it is a sign of pathology. This reflex is named after the Russian neurologist Johann Susman Galant.
Pool reflex
The swim reflex involves placing the baby face down in a puddle. The baby will start rowing and kicking with swimming motion. Reflexes disappear between 4-6 months. Although the baby displays a normal response by rowing and kicking, placing it in water can be a very risky procedure. The baby can swallow a large amount of water while performing this task, therefore the caregiver must proceed with caution. It is advisable to postpone swimming lessons for infants until they are at least three months old, because babies drowned in water can die from water intoxication.
Babkin reflex
Babkin reflexes occur in newborns, and describe the various responses to the application of pressure on both palms. Infants may display head flexion, head rotation, mouth opening, or a combination of these responses. Smaller preterm infants are more susceptible to reflexes, with events observed in 26 weeks' gestational age. Named after the Russian physiologist Boris Babkin.
Parachute reflex
This reflex occurs in a slightly older baby when the child is held upright and the baby's body is turned quickly to face forward (like a fall). Babies will spread their hands forward as if to break the fall, although this reflex appears long before the baby walks.
Other primitive reflexes tested in adult
As mentioned in the introduction, when primitive reflexes are not pressed correctly, they are generally referred to as a sign of a frontal release (though this may be a misnomer). In addition to the previously mentioned reflexes, they include palmomental reflexes, muzzle reflexes, glabellar reflexes or "knock" reflexes.
Primitive reflexes in newborns at high risk
The term high-risk newborn refers to a neonate with significant likelihood of mortality or morbidity, especially in the first month of birth. High-risk newborns will often show abnormal responses from primitive reflexes, or lack of complete response. The performance of primitive reflexes in high-risk newborns often varies in response depending on the reflex (for example, a normal Moro reflex may be present, whereas a walking reflex is absent or abnormal). The normal performance of primitive reflexes in newborns may be associated with a greater likelihood of having a higher Apgar score, higher birth weight, shorter hospitalization time after birth, and better overall mental state.
A recent cross-sectional study assessed primitive reflexes in 67 high-risk newborns, using a sample method to evaluate responses from sucking reflexes, Babinski and Moro. The results showed that sucking reflexes were usually the most frequent (63.5%), followed by Babinski reflex (58.7%), and Moro reflex (42.9%). The study concluded that high-risk newborns exhibit an abnormal primitive reflex response and a more periodic absence, and that each reflex varies in response.
However, with the emergence of simple and effective methods such as Amiel Tison's method of neurological assessment, as a predictor of neurological sequels in neonates and high-risk infants, the importance of primitive reflex assessment decreases.
References
External links
- "PediNeuroLogic Exams - Baby reflection testing film" . Retrieved 2007-10-11 .
- "Medri Vodcast: Neonatology - Neurological examination film of newborns" . Retrieved 2008-05-02 .
Source of the article : Wikipedia
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