Under the Chaddock reflex the neurologist understands a pathological pelvic reflex of the Babinski group. Reflexes in this group are known as pyramidal orbital signs and indicate damage to the central motor neurons. The sensitivity of the Chaddock reflex has become controversial.
What is the Chaddock Reflex?
The Chaddock reflex is a pathological reflex of the limbs. He falls into the so-called Babinski group and is one of the pyramid orbit signs. All pyramid orbit signs are external reflections. Other reflexes from the Babinski group are the Gordon and Babinski reflexes.
As a symptom, these pathological reflex movements are usually associated with a lesion of the central motor neurons. The motor neurons are part of the motor system and thus control the movements of the skeletal muscles. Both voluntary movements and reflex movements are interconnected via the motor neurons. These neurons are part of the pyramidal tracts and thus the central nervous system.
The lower motor neuron is located in the anterior horn of the spinal cord. From here, nerve impulses are transmitted efferently as bioelectrical excitations from the central nervous system to the muscles of the skeletal muscles.
The Chaddock reflex was named after Charles G. Chaddock, who documented the reflex movement in the 20th century. The Japanese K. Yoshimura is considered to be the first to describe the Chaddock reflex, although it was only Chaddock's extensive documentation that made the movement known as a reflex of the Babinski group.
Function & task
Reflexes are automated and involuntary body movements that are not connected in the central nervous system directly in the brain, but rather via the pyramidal tracts. This interconnection makes the movements more immediate and less time-consuming. Only a few milliseconds pass between the trigger and the reflex to this trigger.
Reflex triggers are certain perceptions of the sensory systems. Most of the human reflexes are protective reflexes. Examples of this are the cough reflex and the blink reflex. For example, the lid closes involuntarily as soon as the visual system sees something approaching the eye. This protects the eyeball from injury and loss of function.
The cough reflex, on the other hand, protects against suffocation. It is triggered when the receptors in the mucous membranes of the airways detect irritation. Such irritation is triggered, for example, by food or fluids that accidentally pass through the windpipe rather than the esophagus. Because of their protective function, human reflexes have an evolutionary value.
The human reflex system changes with age. Infants, for example, have significantly more reflexes than adults. In infants, the suckling reflex is the best known reflex. For example, when a finger is put to a baby's mouth, this touch automatically triggers a sucking movement. So the child's mouth does not differentiate between the mother's breast and a limb or even an object like a pacifier. The suckling reflex usually regresses by the infant's first year of life, as the child is no longer dependent on it from this age.
The entire reflex system changes during the first few years of life. These changes are mainly due to the development of higher-level movement control. The motor neurons are responsible for the overall control of the voluntary and reflex motor skills.
In addition to the sucking reflex, infants under one year of age have all the reflexes of the Babinski group. The chaddock reflex is also physiological for babies. A pathological phenomenon is only mentioned in adults. At an age of less than one year, the overriding control of motor skills is not yet fully developed. Therefore, muscle groups that are close together, such as those of the toes, always move as a group.In the Chaddock reflex, for example, brushing the outer back of the foot triggers an upward movement of the big toe. The other phalanges of the toes perform a spreading movement at the same time.
If this phenomenon is observed in an adult, then there is, so to speak, a regression to a stage during which the individual muscle groups were not yet individually activatable. Since the central motor neurons are the superordinate control authority for movements, damage to these structures can be assumed.
Illnesses & ailments
Like all other reflexes from the Babinski group, the Chaddock reflex is to be assessed as a symptom. As a rule, the reflex movement is symptomatically associated with lesions of the central motor neurons.
The sensitivity of the Chaddock reflex is, however, controversial. Although the reflex examination has so far been a standard examination in neurological diagnostics, the presence of a pathological reflex alone is far from sufficient for the diagnosis of neurological diseases. For example, only several pyramidal orbit signs are an actual indication of motor neuron damage. In addition, the rest of the findings must also be characterized by abnormalities in the area of motor skills.
If the first motor neuron is damaged, the primary findings are mostly spastic symptoms. Damage to the second motor neuron, on the other hand, manifests itself in muscle weakness, insecurity of movement or paralysis. Both motor neurons can be damaged by various central nervous system disorders.
The best known of these diseases are multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). ALS is a degenerative disease of the motor nervous system. Multiple sclerosis, on the other hand, is an autoimmune disease in which the person's immune system attacks the body's own nervous tissue and causes inflammation in it. Pyramid orbit signs such as the Chaddock reflex are used as criteria for the unfavorable prognosis, especially at the beginning of the disease.
