Neurologists refer to the Gordon reflex as a pathological foot reflex. The pathological toe movement is a pyramidal tract sign and indicates damage to the central motor neurons. Causes include diseases such as multiple sclerosis.
What is the Gordon reflex?
The physician triggers the reflex movement by kneading the patient’s calves. The big toe then involuntarily stretches upward, while the other toe limbs perform grasping movements. Neurology knows a pathological reflex of the toes as the Gordon reflex, which can occur symptomatically in the context of neurological diseases. The reflex movement is also called toe sign, Gordon-Scharfer reflex or calf reflex and can be observed on the individual foot limbs. The physician triggers the reflex movement by kneading the patient’s calves. The big toe then involuntarily extends upward, while the other toe limbs perform grasping movements. The Gordon reflex is considered one of the pyramidal tract signs and is indicative of lesions of the central motoneurons. These neurons are motor switch sites in the central nervous system that are responsible for motor function. Pyramidal tract signs refer to the pyramidal tracts of the spinal cord. These motor and central nervous system pathways are located in the anterior horn of the spinal cord and control primarily voluntary movements, but also reflex movements. The Gordon reflex was named after its first describer, Alfred Gordon. This US neurologist speculated in the 20th century about the pathological value of reflex movement in adults.
Function and task
A control center of motor function is located in the anterior horn of the spinal cord in humans. The neural pathways are also known as pyramidal pathways and consist of several motoneurons. The so-called first motoneuron is located in the cerebral cortex. This neuron is also known as the upper motoneuron. The second motoneuron, on the other hand, is located directly in the anterior horn of the spinal cord and is called the lower motoneuron. Both motoneurons are alpha neurons. Thanks to their thick axons, these motor neurons have a conduction velocity of about 80 m/s and influence the fibers of the skeletal muscles. The pyramidal tracts of the anterior horn of the spinal cord are efferents. As efferent pathways, they conduct information through bioelectrical impulses from the central nervous system to organs of success in the body. In the motor nerve pathways, the muscles of the skeletal musculature are the organs of success. Thus, the muscle fibers receive the order to move. Especially the reflex control can only run through the spinal cord. Many of the human reflexes are protective reflexes, which should protect against injuries. Individual perceptions are possible triggers, especially those of the visual system. If the control center of the motor reflexes were located in the brain, the muscles would not execute the movements in time. This would mean that the reflexes would no longer be able to fulfill their protective function. This is because impulses controlled via the brain would not reach the muscle fibers quickly enough. Movement impulses with wiring in the anterior horn of the spinal cord have shorter distances to travel and thus reach the target organs more quickly. To illustrate this, here is an example: When the mucous membrane of the respiratory tract is irritated, it triggers a cough reflex. This is to prevent aspiration of fluid and food particles. The cough reflex thus protects the person from choking. If the circuitry were too long, the person would only cough after he or she had already inhaled the liquid or food components. The actual protective function of the reflex movement would thus be lost. Compared to an infant, the adult has incomparably fewer reflexes. Babies, for example, have a sucking reflex that is triggered by touching their lips. In the course of their natural development, they lose this reflex because sucking is no longer life-sustaining for them. The Gordon reflex is also a physiological, or natural, reflex for infants under one year of age. So when their calves are kneaded, on one or both sides their big toe moves up. The rest of the foot limbs perform an analogous grasping movement. At a certain age, this reflex is lost.
Diseases and ailments
In adults, the Gordon reflex is considered pathologic and refers to damage to motor neurons. Such lesions probably interfere with the higher-level control of motor function.The muscles that still belong together in infancy are therefore stimulated together again. The Gordon reflex thus arises from lesions in the central nervous system and is thus to be understood as a symptom of a specific primary disease. Both the Oppenheim reflex and the Babinski reflex, as well as the Chaddock reflex or the Strümpell signs can accompany the Gordon reflex. They are all pathological reflexes from the Babinski group. This symptomatic group of reflexes is also known as pyramidal tract signs. Meanwhile, the diagnostic value of the Gordon reflex is doubted. Only if other reflexes from the Babinski group can be triggered in an individual case is it still considered a reliable diagnostic criterion today. The entire Babinski group is associated with damage to the central motor neurons. The examination of these pathological reflexes is a standard in neurological diagnostics. A lesion of central nervous system motoneurons can be due to various primary diseases of the central nervous system. For example, the degenerative disease ALS is a possible cause. In this disease, the motor nerve cells in the motor nervous system gradually degenerate. In addition to the motor neurons in the brain, the spinal cord can also be affected by the deterioration. If the first motoneuron is damaged, muscle weaknesses, movement uncertainties or even paralysis occur. Damage to the second motoneuron, on the other hand, causes spasticity. MS can also damage the motor neurons under certain circumstances. In this autoimmune disease, the immune system attacks central nerve tissue, causing inflammation. Pyramidal tract signs shortly after the onset of multiple sclerosis are associated with a prognostically unfavorable course.
