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How Babinski Reflex Is Used to Diagnose MS

How Babinski Reflex Is Used to Diagnose MS

Multiple Sclerosis

In multiple sclerosis, the body's immune system attacks the myelin (protective sheath), which covers the nerve fibers. When the myelin sheath is damaged, there would be communication problems from the brain and to the rest of the body. Depending on the severity of the disease, nerve fibers eventually deteriorate or become permanently damaged. 

The damage can further cause vision problems, muscle weakness, and various other symptoms. In one type of MS, the symptoms remit, and for a long period of time, they partly or completely clear up. In the other type, the symptoms become worse as the disease progresses.

Diagnosing Multiple Sclerosis

There is no specific test that can identify MS. When it comes to diagnosing MS, doctors often rule out other medical conditions that have the same signs and symptoms. It is called as a differential diagnosis. The doctor would likely begin by asking about your medical history and then conduct a physical examination.  

A sign of relapsing-remitting MS is a history of at least two attacks. These attacks should be separated by a period of reduced symptoms or no symptoms. If there is a decrease in the functioning of the central nervous system, then an MS diagnosis can be suspected.

A localized decrease in the function of the nerves can be seen through a neurological exam. A decrease in nerve function includes abnormal or decreased sensations, limited ability to move certain body parts, changes in speech or vision, and loss of neurological function. Usually, the location of nerve damage is indicated by the type of neurological deficit. It is indicated by a positive Babinski sign.

Other diagnostic tests may include an eye examination, which tests for:

  • Abnormal pupil response
  • Changes in eye movements
  • Changes in the visual field
  • Rapid movement of the eyes
  • Problems with the eye's internal structure
  • Decreased visual acuity

Multiple sclerosis can be confirmed by the following tests:

  • MRI scan of the head and spine
  • Cerebrospinal fluid (CSF) analysis, which includes CSF oligoclonal banding
  • Lumbar puncture 

Neurological Exam

A thorough neurological examination is done to arrive at an accurate MS diagnosis. The objective signs of MS may include:

  • Abnormal eye movements or pupil response
  • Spasticity
  • Abnormal reflex responses
  • Sensory disturbances 

Involuntary and instantaneous movements of body parts are reflexes, which are given in response to stimuli. A soft hammer may be used by a neurologist to check whether reflexes are brisk, weak, or absent in the ankles, elbows, knees, and joints.

On either side of the body, unequal reflexes indicate that nerve functions are impaired. In the abdominal area, these reflexes are absent or abnormal. The Babinski reflex is a common sign in MS. Damage to the major nerve pathways is indicated by a positive Babinski reflex. The Babinski sign was named after the French neurologist Joseph Babinski. He studied multiple sclerosis, post-traumatic stress disorder, tumor in the spinal cord, syphilis, and other diseases.

To test for the Babinski reflex, doctors use a blunt pointed object to scrape the foot, which starts from the heel to the toes. The toes point downward or stay still in normal reflexes. However, if the big toe points upward and the rest of the toes fan out, the Babinski reflex is abnormal. The Babinski reflex seen in newborns and infants is a normal occurrence since their neurological system is not yet fully developed. However, a positive Babinski reflex in older children and adults may indicate conditions such as meningitis, ALS, brain tumor, spinal cord injury, stroke, tumor, or multiple sclerosis. 

When the Babinski sign is positive, it may indicate corticospinal tract damage. The corticospinal tract is a long nerve axon. This axon starts from the cerebral cortex and travels downward from the brain stem and spinal cord. It is also called as the pyramidal tract. Depending on the type of damage, whether a permanent or temporary one, a positive sign may result. You will get a clue whether your MS is progressing when you are at your doctor’s clinic and you pay attention to the results of the test.

In a neurological exam for MS, the doctor will test many involuntary responses or reflexes to stimuli. The doctor may tap using a rubber mallet. He may measure the response by tapping various tendons. However, the scraping of the bottom of the foot does not involve the use of a rubber mallet.

What does the doctor look for in a Babinski response?

  • Normal response for anybody older than 2 years old: Downward movement of all toes or staying still.
  • Positive Babinski sign: Upward movement of the big toe while other toes fan out for a brief second.

What causes the big toe to extend or move upward?

The central nervous system is not yet fully developed in newborns and infants up to the age of 2. Some portions of the corticospinal tract of young infants are still not myelinated. If there is a disruption in the communication between the brain and the foot, then scraping the foot acts like a stimulus that causes the muscles to flex on top of the foot, which leads to the extension of the big toe. A lesion or damage along the corticospinal tract is indicated by the Babinski sign.

The Babinski sign may disappear as early as 12 months when the corticospinal tract matures. 

Positive Babinski Sign

An abnormal Babinski sign may not always indicate MS. Several conditions may cause an abnormal Babinski reflex. They include:

All these conditions involve the corticospinal tract. However, not every person with MS will show a Babinski reflex. Only those who have damage along the specific connection between the brain and spinal cord may show the Babinski sign. If the Babinski reflex is abnormal, it may be permanent or temporary.

Other Tests

Babinski reflex is actually a simple plantar reflex used to diagnose MS. Other tests include the Oppenheim’s sign and Chaddock’s sign. Stimulus is applied in a circular direction to elicit Chaddock’s sign. This stimulus is applied down the foot around the ankle from the heel to the little toe. These signs probably appear when more damage has occurred. 

Multiple sclerosis is a degenerative condition of the central nervous system. In this condition, progressive lesion occurs in the brain and spinal cord. An abnormal Babinski reflex may indicate MS, but not in all people.

Key Takeaways

  • Multiple sclerosis is a degenerative condition of the central nervous system. 
  • The Babinski reflex seen in newborns and infants is a normal occurrence since their neurological system is not yet fully developed. However, a positive Babinski reflex in older children and adults may indicate conditions such as meningitis, ALS, brain tumor, spinal cord injury, stroke, tumor, or multiple sclerosis. 
  • The Babinski reflex is a common sign in MS. However, not every person with MS will show a Babinski reflex.