Hypoglossal Nerve and the Upper Cervical Spine

In Upper Cervical Chiropractic, the focus is on the neurophysiology and biomechanics of the Craniocervical Joint. The four main sections to consider are:

1. The Foramen Magnum of the Occipital bone 

2. The Atlas vertebra (1st cervical bone)

3. The Axis vertebra (2nd cervical bone) 

4. The Brainstem of the Nerve System

The Nerve System in general does four main things: 

1. It controls all the movements we make

2. Senses everything we feel

3. Regulates all our body organs

4. Relates us to the outside world

To simplify, the brain stores information and generates electrical signals. The brain uses nerve fibers in the form of spinal nerves, cranial nerves and peripheral nerves to send that information out to the body. 

There are also nerve fibers at every organ, gland and tissue of the body that send information back up to the brain for interpretation. All the trillions of nerves that make up the Nerve System communicate with each other in a complete, unbroken cycle. 

An important meet-up point in the nerve cycle occurs at the upper cervical spine. This is where the majority of nerve signals, from the brain and body, intersect. The upper cervical spine protects and surrounds the inferior section of the brainstem and superior section of the spinal cord. 

Let’s look at cranial nerve XII (12), the hypoglossal nerve, and its connection to the upper cervical spine. 

The hypoglossal nerve is the most inferior cranial nerve located on the brainstem. It exits the cranium via the hypoglossal canal found on either side of the foramen magnum. Upon exiting, it travels down the neck, passing between the internal carotid artery and the internal jugular vein. It passes forward under the tongue to innervate most muscles of the tongue. The hypoglossal nerve communicates with the ganglion trunk of the vagus nerve, superior cervical ganglion and ansa cervicalis (cervical plexus of C1-C3). 

When nerves get stressed, it effects their sensitivity, perception and behavior. There are three types of stress we deal with in life. The stresses are physical, chemical and emotional in nature. These stresses create nerve tension, which imbalances the muscles of the spine. 

The Nerve System will adapt to the best of its ability to these stresses and help bring the spine back into balance. If the stresses are too great for the Nerve System to adapt, compensations arise. A compensation that occurs in the upper cervical spine is a vertebral subluxation.

A vertebral subluxation will cause the Atlas and Axis bones to get locked in a misaligned position. This lock will perpetuate nerve tension, which imbalances the spine. A vertebral subluxation obstructs communication along the nerve cycle. This interferes with normal sensation, perception and behavior of the Nerve System. Nerve System function is disrupted.

A functional disruption of the hypoglossal nerve will cause the tongue to deviate to one side when stuck out. It can also cause tongue paralysis and/or atrophy to occur on one side of the tongue. 

The goal of Chiropractic is to correct nerve tension and spine imbalance. Chiropractors do this by adjusting the vertebral subluxation of the upper cervical spine. Correcting the subluxation better optimizes the function of the brainstem and associated nerves. The Nerve System can sense, perceive and behave at a greater potential when a subluxation is corrected. 

- Jarek Esarco, DC, CACCP

Related Blogs:

1. Cranial Nerve/Spine Connection

2. Breastfeeding Difficulties and the Upper Cervical Spine

Other Resources:

Jarek Esarco, DC, CACCP is a pediatric, family wellness and upper cervical specific Chiropractor. He is an active member of the International Chiropractic Pediatric Association (ICPA). Dr. Jarek has postgraduate certification in Pediatric Chiropractic through the ICPA. Dr. Jarek also has postgraduate certification in the HIO Specific Brain Stem technique through The TIC Institute. Dr. Jarek is happily married to his wife Regina. They live in Youngstown, Ohio with their daughter Ruby.