What is the Hypoglossal Nerve?
The hypoglossal nerve, also known as cranial nerve XII or the 12th cranial nerve, is a motor nerve primarily responsible for controlling most tongue muscles, which is essential for tongue movements. This nerve is vital for functions like speech, swallowing, and chewing.
Key Characteristics:
- Origin: The hypoglossal nerve originates in the medulla oblongata, a section of the brainstem.
- Pathway: It exits the skull via the hypoglossal canal and extends to the tongue, innervating intrinsic and extrinsic tongue muscles.
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Functions:
- Regulates tongue movements, including protrusion, retraction, and lateral motions.
- This is essential for clear speech and effective swallowing.
What Is Hypoglossal Nerve Stimulation (HGNS)?
Hypoglossal Nerve Stimulation (HGNS) is a treatment for obstructive sleep apnoea (OSA). It uses a surgically
implanted device that applies mild electrical stimulation to the hypoglossal nerve, which controls tongue movements,
to prevent the tongue from blocking the airway. This upper airway stimulation is synchronised with the patient's breathing
patterns to ensure uninterrupted airflow during sleep. It provides a more comfortable and discreet solution for those struggling with CPAP machines, enhancing sleep quality without needing masks or hoses.
How Does HGNS Work?
A HGNS device usually consists of a small generator, a sensing lead, and a stimulation lead. Once implanted, the device monitors breathing patterns during sleep. When it detects potential airway blockages, it delivers mild stimulation to the hypoglossal nerves that control tongue and airway muscles. This stimulation keeps the airway open, allowing for uninterrupted breathing and significantly reducing the occurrence of sleep apnoea episodes.
Is HGNS Right for You?
An ENT doctor will determine if you are a suitable candidate based on factors such as:
- Diagnosed with moderate to severe obstructive sleep apnoea
- Struggle with or unable to get consistent benefit from CPAP
- Not significantly obese
- Over the age of 18
What to Expect During HGNS Therapy
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Consultation and Evaluation
The journey begins with a thorough consultation and evaluation process. Patients meet with a specialist to determine their eligibility for the procedure. This step ensures personalised and tailored treatment plans for optimal outcomes.
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Implantation Procedure
Patients can have peace of mind knowing that they will receive appropriate anaesthesia to ensure a
comfortable experience during the procedure. A nerve stimulator device and battery are placed under the skin of the patient's chest, which are then connected to the nerve that stimulates the tongue. The device will monitor the patient's breathing and sends an impulse to the tongue during every breath while sleeping, keeping the airway open.
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Ongoing Support and Monitoring
Follow-up appointments with the ENT specialist for device activation and monitoring ensures that progress is monitored, concerns are addressed, and settings are fine-tuned to enhance results.
Frequently Asked Questions
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Is the implantation procedure safe?
Yes, the implantation procedure is typically well-tolerated and performed by skilled ENT specialists trained in HGNS.
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How long does the implantation procedure take?
It usually takes a few hours and is performed under general anaesthesia.
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Will I still need to use a CPAP machine after HGNS?
In most cases, HGNS removes the need for a CPAP machine, especially since it is intended to be an alternative for people with OSA who cannot tolerate or attain good results with a CPAP.
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Are there any side effects or risks associated with HGNS?
As with any medical procedure, there are potential risks and side effects. Common side effects include temporary discomfort and soreness around the implant site.
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Can I go through airport security with a HGNS implant?
Yes, you can. However, as it may set off the metal detector, you should let security personnel know beforehand that you have an implant and carry a device identification card with you.
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How do I care for my HGNS implant?
After your surgical wounds have healed, you won’t need to follow any special precautions. The battery in the generator typically lasts around 10 years, after which it will need to be replaced through a minor outpatient procedure.
