The Hypoglossal Nerve (Cranial Nerve XII) is the primary motor nerve of the tongue. When the tongue does not work properly then difficulty chewing, swallowing, speaking or breathing can occur. One cause of tongue impairment is harmful strain upon the Hypoglossal Nerve as it travels from the brain to the tongue. The opening through which the Hypoglossal Nerve travels is called the Hypoglossal Canal. It is an important area to assess and mobilize if your client has impaired tongue function or tongue atrophy.
There are two Hypoglossal Nerves, a left and a right. The Hypoglossal Nerves pass through the Hypoglossal Canals (HCs) on their way from the brain to the tongue. The left Hypoglossal Nerve passes through the left Hypoglossal Canal, and the right Hypoglossal Nerve passes through the right Hypoglossal Canal. Adverse strain of the occiput, occipital condyles, craniosacral system membrane layers, foramen magnum, structures of the upper cervical region, or fascia of the occipital cranial base can distort the shape of the HCs. This shape distortion can place harmful stress upon the Hypoglossal Nerves.
The following description is one way to assess and mobilize restrictions of the HCs. However since the occiput has not completed its ossification process until the age of eight, when working with children only use the assessment and mobilization steps #1 through #3, and use the utmost of delicate touch and soft intention.
Throughout this description the client is supine (on their back). The practitioner is seated at the client’s head.
Assess the area of the HCs:
Hand Positions:
Place hands under the occiput, finger tips at the occipito-atlantal junction (where the occiput articulates with C1).
1. Feel the shape of the occiput while using “0″ grams pressure upon the occiput.
Imagine a line drawn through the centerline of the client’s face and cranium from the center of their chin to the center of the top of their head.
Does the occiput feel symmetrical in relationship to this line? Does it feel tilted so that one side is more inferior (towards the feet) than the other side, or twisted so that one side is more anterior (towards the front) than the other side? Does one side or the entire occiput feel flat, or does one side or the entire occiput feel excessively bowed? These shapes indicate probable strain of the intracranial membrane system, occiput, foramen magnum, occipital condyles or the HCs.
2. Feel the occiput and HCs widen and narrow in synchrony with the craniosacral rhythm (CSR) while using “0″ grams pressure.
Is there an equal range of motion during the flexion and extension phases of the CSR? Does the quality of motion feel smooth, unencumbered and balanced; does it feel thick, rigid or lopsided? Imbalance or strain in synchrony with the CSR indicates probable strain of the intracranial membrane system, occiput, foramen magnum, occipital condyles or the HCs.
Mobilize the area of the HCs:
1. Mobilize restrictions of the thoracic inlet area.
Place hands on the upper thoracic area so that the posterior hand rests midline under the C7/T1 area and the anterior hand is upon the collarbones and upper thoracic area. Come to “0″ grams pressure with both hands, and then set the intent for the fascia and structures in this area to move into positions of release. Follow the tissue as is does so until a feeling of softening occurs.
2. Mobilize restrictions of the hyoid area.
Change hand positions so the fingers of one hand are under the posterior neck area. Place the thumb and second finger of the other hand upon the anterior, lateral aspects of the hyoid. Come to “0″ grams pressure with both hands while setting the intent for the fascia and structures in this area to move into positions of release. Follow the tissue as is does so until a feeling of softening occurs.
3. Mobilize restrictions of the tissue in the area of the occipito-atlantal junction and traction release the occiput in a superior direction.
While seated at client’s head, place both hands under the occiput with your fingertips at the occipito-atlantal junction. Soften the feeling in your hands while setting the intent for the client’s tissue to soften under your fingertips. Wait and follow the tissue until a feeling of softening occurs.
Then set the intention to traction the occiput in a superior (towards the top of the head) direction using “0” grams pressure. Follow the tissue until a feeling of softening occurs in a superior direction.
4. Mobilize restrictions of the occiput.
Hands remain under the occiput at “0″ grams pressure. Set the intention for the fascia and structures of the occiput, both inside and outside of the occiput, to move into positions of release. Follow the tissue as it moves into positions of release until a feeling of softening occurs.
5. Mobilize restrictions of the HCs.
Hands remain under the occiput at “0″ grams pressure with a focus upon your fingertips. Imagine that your fingertips are delicately contacting the area of the HCs. Set the intent for the fascia and structures in the area of the HCs to move into positions of release. Follow the tissue with your fingertips as is it does until a feeling of softening occurs under your fingertips.
6. Mobilize restrictions of the Hypoglossal Nerves.
Hands remain under the occiput at “0″ grams pressure with a focus upon your fingertips. This time imagine that your fingertips are resting delicately upon the Hypoglossal Nerves as they pass through the HCs. Set the intent for the Hypoglossal Nerves to move into positions of release. Follow the nerves with your fingertips until a feeling of softening occurs.
7. Use the dynamic fluid motion of the craniosacral system to enhance and integrate correction.
Hands remain under the occiput at “0″ grams pressure. Follow the occiput as it widens and narrows in synchrony with the CSR at “0″ grams pressure. When the occiput arrives at end range of widening and end range of narrowing, apply the intent to encourage the occiput further into its end ranges. The intent to encourage lasts for about one second or less at each end range. Continue to encourage at end ranges until a feeling of softening occurs in both directions. In Upledger CranioSacral Therapy, this is referred to as “Cranial Pumping”.
8. Enhance correction by facilitating integration between the tongue muscles and the occiput.
While seated at the side of your client, slowly slide the palm of one hand under the occiput and gently place the fingers of your other hand at the area of the base of the tongue under the chin. While using “0” grams pressure, set the intent for the tongue, occiput, foramen magnum, HCs, Hypoglossal Nerves, fascia, cervical area, craniosacral system membrane layers and brain tissue to integrate the corrections that have occurred. Wait to feel softening and a feeling of greater connection between your hands.
If you are working with clients who have difficulty chewing, swallowing, speaking or breathing; or babies having difficulty sucking or swallowing; then you may want to try the HC sequence during several sessions to see if it helps. Also, using this sequence periodically can enhance your client’s overall well-being, even if there is no tongue issue, since the occipito-atlantal junction is a common area of tissue restriction, fluid congestion and strain upon the central nervous system.
References:
Moeckel, Eva, D.O., M.R.O., M.S.C.C., and Mitha, Noori, D.O., M.R.O., Textbook Of Pediatric Osteopathy, Churchill Livingston Elsevier, Philadelphia, PA., 2008.
Magoun, Harold I., A.B., D.O., F.A.A.O., Osteopathy In The Cranial Field, Third Edition, The Journal Printing Company, Kirksville, MO., 1966. 1976.
