Overview of Babinski Reflex
In 1896, a doctor named Joseph Babinski discovered something called the Babinski reflex, which is also known as the plantar reflex. From then on, it has become a regular part of the checking process when performing a neurological exam, which is a test that doctors use to check for brain disorders.
It’s a straightforward reflex to trigger, and you don’t need any complicated equipment. Another advantage is that it doesn’t rely heavily on the patient’s participation, so even if a patient isn’t able to cooperate or participate fully in the exam, this test can still be carried out. This could be particularly useful in situations where the patient can’t communicate due to their condition.
Anatomy and Physiology of Babinski Reflex
The Babinski reflex is a test doctors use to check the health of a nerve pathway known as the corticospinal tract (CST). This pathway starts in the brain, travels down through the brainstem and spinal cord, and plays a key role in controlling movement. The CST talks to motor neurons, which are basically the body’s message carriers for muscle contractions. Some motor neurons start in the brain (upper motor neurons) and others are based in the spinal cord (lower motor neurons).
About 60% of the CST fibers come from areas of the brain that control movements and the remaining portion originates from areas that process sensory information. Any damage to the CST can cause something called a Babinski sign.
Generally, if you stimulate the outer part of the foot, the toes curl down and inward. This is because the pressure is detected by nerves in the foot, which relay a signal up the leg via the tibial and sciatic nerve to the lower end of the spine, causing a muscle contraction in the foot. Sometimes, there is no response to this kind of stimulation, which is also normal and doesn’t necessarily mean there is a problem.
However, if the CST is damaged, this can cause a different reaction. Instead of the toes curling down, the big toe may extend upwards and the other toes spread out. This reaction, known as the Babinski sign, occurs because without a healthy CST, the sensory input spreads beyond where it should in the spine, activating other nerve roots and causing these unusual toe movements.
This unusual toe movement is normal in infants under 24 months old, whose CST is still developing. Also, the Babinski reflex can sometimes be seen when a person is asleep.
Why do People Need Babinski Reflex
The Babinski reflex is a test done routinely in a neurological exam (an exam of your nervous system) to check the health of a part of the nervous system called the CST, short for corticospinal tract. This part of your nervous system is like an information highway connecting your brain, brainstem, and spinal cord. The presence of a specific response in this test, referred to as the Babinski sign, indicates damage to the CST which often signifies an issue within your central nervous system.
The purpose of the Babinski reflex test isn’t just to detect any potential issues in the central nervous system. It also actively provides valuable information related to the presence of damaging conditions that affect the nervous system. This test is particularly essential when there’s a chance of a spinal cord injury or stroke. The test could act as an early warning system identifying these emergency situations before they fully develop.
When a Person Should Avoid Babinski Reflex
The Babinski reflex is a simple test doctors perform, typically on the bottom of your foot, to check the health of your brain and spinal cord. However, sometimes this test should not be performed. For instance, if there is an injury or infection in the foot to be tested, this could cause the results to be unclear. In these cases, the doctor might use another method to get similar information about the health of your brain and spinal cord.
Equipment used for Babinski Reflex
The Babinski reflex, which is a reaction where your big toe moves upward when the bottom of your foot is touched, should be tested using a dull, rounded object that won’t cause any pain or harm. Sharp items are not recommended for this procedure. Typically, the blunt end of a tool used to test reflexes, a flat wooden stick known as a tongue depressor, or even the edge of a key are used.
Preparing for Babinski Reflex
It’s important for patients to be at ease and feel comfortable during the examination. They should know that it might feel a bit uncomfortable or even ticklish, but nothing to be worried about. Before starting the examination, the doctor will check to make sure that the bottom of the foot, known as the plantar surface, doesn’t have any injuries or skin issues.
How is Babinski Reflex performed
The Babinski sign is tested by running a small instrument up the outer side of the foot, from the heel to the toes, and then across the foot pad towards the big toe. There are a few different ways to check for the Babinski sign, which are all aimed at seeing if the big toe flexes backwards (dorsiflexes).
Some common methods are: the Chaddock method, where they stimulate beneath the outer ankle bone; the Gordon method, where they squeeze the calf; the Oppenheim method, where they apply pressure to the inner side of the shin bone; and the Throckmorton method, where they tap the joint of the big toe.
The reason these methods produce the same response is likely because they trigger the same reaction as the traditional Babinski test. These variations can be especially helpful in patients who pull away significantly when the standard Babinski reflex test is performed.
What Else Should I Know About Babinski Reflex?
When a doctor tests the Babinski reflex, they’re checking how your toes respond to certain stimulation. They specifically look for an upward movement of the big toe and the spreading out of your other toes. This is considered a positive Babinski reflex. If your toes bend downwards or don’t move at all, this is seen as a negative reaction or having no significance.
The presence of a positive Babinski reflex can show that there might be something wrong with the main pathway that carries messages from the brain to different parts of the body. In fact, it could be the first sign of a spinal cord injury after a sudden trauma. However, the doctor needs to interpret the results carefully, because sometimes patients might pull their foot away due to the ticklish stimulation.
For patients who can’t respond due to being unconscious, doctors might see a ‘triple flexion response.’ This means that there’s not only upward movement of the big toe and fanning of other toes, but there’s also bending of the thigh, leg, and foot. This represents a serious dysfunction in the main communication pathway from the brain. Doctors must be careful to distinguish this from a simple withdrawal response. The triple flexion response is very uniform, unlike the withdrawal response which can vary each time it’s stimulated.