What is the Babinski reflex?The bambini-reflex is a pathological reflex of the foot, which can occur when the lateral edge of the foot is brushed.
The bambini-reflex is a pathological reflex of the foot, which can occur when the lateral edge of the foot is brushed. The reflex movement is also called the Babinski sign and is a pyramidal sign from the Babinski reflex group. The adult is therefore a pathological reflex that indicates neuronal disease. Other names for the phenomenon are the big toe reflex or toe reflex.
The pyramidal tract signs are usually interpreted as an indication of lesions of motor neurons. These efferent neurons derive bioelectric impulses as action potentials from the central nervous system and lead them into the muscle fibers. Thus, the motor neurons are the hub for body movements. Both voluntary movements and reflex movements are interconnected via the neurons. The first motor neuron sits in the motor cortex of the brain. The lower motoneuron, on the other hand, lies in the anterior horn of the spinal cord.
As a symptom, the Babinski reflex can occur with any type of damage to the two motor neurons. This means that both inflammation and degenerative phenomena may be the primary cause of the pathological reflex.
The Babinski reflex was named after Joseph François Félix Babinski. The French neurologist first linked the great toe reflex in the 19th century to neural diseases.
Function & Task
Human reflexes are motor reflexes that have an evolutionary background. Most of them are protective reflexes, such as the eyelid reflex, which is supposed to protect the eyeball and thus the visual system. When something approaches the eye, the eyelid closes involuntarily and automatically. The cough reflex also has a protective function. It is triggered when the mucous membrane of the respiratory tract becomes heavily irritated. Thus, liquids and food remains to be expelled from the respiratory tract, if the person is swallowed. Thus, the cough reflex protects the organism from suffocation.
Humans can only influence their reflexes to a certain degree and only consciously perceive them in moderation. Reflexes change with age. An adult, for example, has far fewer reflexes than a baby, for example. For example, babies have a sucking reflex. The suckling motion is triggered as soon as the infant's mouth is touched. It is irrelevant whether the breast, a finger or even an object like the pacifier actually touches the baby's mouth. The teat reflex loses itself after a certain age. The time to reflex loss can vary gradually from person to person. On average, sucking can not be triggered at around the age of one.
In addition to the sucking reflex babies have many more reflexes. One of them is the Babinski reflex. When the lateral foot margin of babies is smeared, their big toe goes up and the other phalanges are gripping at the same time. In this stage of development, the muscle groups of the foot joints are still activated together. Like the nipple reflex, however, the Babinski reflex also loses itself after an average age of one year.
From this age on, motor function is subject to higher-level control, which allows the separate activation of the individual muscle groups. This control is exercised over the upper and lower motoneuron. Therefore, if the Babinski reflex can be observed on the adult, there is a loss of superior control and the formerly activated muscle groups can therefore be activated again at the same time.
Diseases & complaints
The Babinski reflex is considered by neurologists as a symptom. In the past, the pathological reflex received a much higher priority than today. In the meantime, the mere presence of the Babinski sign on one or both feet is not considered diagnostic. Therefore, the reflex is interpreted today only in combination with other reflections of the Babinski group and against the background of other findings as a tangible indication of damage to the motor neurons. Another reflex of the Babinski group is, for example, the Gordon reflex.
Conspicuous findings may be paralysis, muscle weakness, gait insecurity or spasticity. If stroking does not trigger the Babinski reflex, but only the upward movement of the big toe, this alone is not sufficient for a suspected diagnosis of lesions on the motor neurons. In lesions of the first motor neurone concomitant spastic phenomena are present. If, however, a suspected diagnosis for damage to the second motor neuron, muscle weakness or paralysis can be observed.
Both neurons can be damaged by central nervous system diseases such as ALS or MS. In the autoimmune disease multiple sclerosis, immunological inflammation is responsible for the lesions. By contrast, the degenerative disease of amyotrophic lateral sclerosis progressively degenerates the motor system and thus attacks both the brain and the spinal cord.
The reflex examination is a standard procedure of neurological diagnostics. If pathological reflexes can be established, this has not only diagnostic, but often also prognostic value. In multiple sclerosis, pyramidal tract signs, such as the Babinski reflex, are considered to be unfavorable prognostic factors if they occur at the onset of the disease.