Cranial Nerve Conditions

The cranial nerves protrude directly from the brain, not the spinal cord. There are twelve cranial nerves, but not all can be rated. The ratable ones include the trigeminal nerve, the facial nerve, the glossopharyngeal nerve, the vagus nerve, the spinal accessory nerve, and the hypoglossal nerve. If another cranial nerve is affected, it is rated on whatever symptoms it causes.

The Cranial Nerve Rating System

This rating system is used for rating both the Cranial Nerves and the Peripheral Nerves (the nerves on the Low Back and Upper Back pages).

There are a few basic rules/principles to follow when rating a cranial or peripheral nerve condition.

First, all nerve conditions are rated based on the loss of function of the affected body part. There are three different categories a nerve condition can be rated under: paralysis, neuritis, and neuralgia. The condition must satisfy certain terms to be rated under one of these categories. These terms are discussed below. Once it is determined which of the three categories the nerve condition falls under, it can then be rated either under that category or on limited motion, whichever gives the higher rating. It is important to note that if the nerve condition is causing the limited motion, then only one rating can be given either under a nerve code or under limited motion. If, however, the limited motion is NOT caused by the nerve condition, then it can be rated in addition to a nerve rating.

Second, when deciding which of the three categories a condition fits in, it is important to keep in mind that the actual loss of function of the body part is the main defining criteria. In other words, if the nerve leading to a muscle in the shoulder is completely paralyzed, it is not necessarily rated as completely paralyzed. If the shoulder can no longer move the arm or function at all, then it can be rated as completely paralyzed. In most cases, however, the muscles in the shoulder and arm that are not affected by the paralyzed nerve will often compensate for the loss of function, and moving the arm will still be possible. This is especially the case since the nerves rarely work alone, meaning that more than one nerve often works a single muscle. Because of this, some movements are controlled by numerous nerves and may still be able to take place if one is damaged. In cases like this, the nerve cannot be rated as completely paralyzed. We’ll work an example in a bit to help clarify this rule.

Third, if the nerve affected is one that controls the eyes, ears, nose (smell), or tongue (taste), then it is not rated under a nerve code at all. Instead, the condition is rated based on the limitation of the senses. See The Eyes, The Ears, and the Taste and Smell pages for more information on rating these conditions.

Fourth, each nerve is paired, meaning that there are 2 of every nerve, one for each side of the body. For the peripheral nerves, if both are affected, then the bilateral factor is added. The bilateral factor, however, does NOT apply to any of the cranial nerves. So, if both cheeks are affected by a nerve condition, then both can be rated separately, but the additional bilateral factor is not given.

Fifth, each nerve has three different possible codes under which it could be rated:

• Paralysis of the nerve—the nerve itself, not the affected body part, cannot function at all. This can be complete paralysis or partial paralysis.

• Neuritis of the nerve—the nerve still functions, but it is swollen, irritated, and very painful. All cases of neuritis will have at least one of the following:

1. a decreased ability to sense

2. muscle atrophy

3. loss of reflexes

• Neuralgia of the nerve—the nerve causes occasional or constant pain. There can also be tingling, numbness, etc.

For a condition to qualify for the next highest category, it must satisfy all the criteria. For example, a condition with severe pain but no other symptoms would still have to be considered neuralgia since the other symptoms, like muscle atrophy, that are required to call a condition neuritis aren’t present.

Sixth, each of these codes is rated based on a degree of severity.

Paralysis

• Complete: This is defined for each nerve a little differently, but basically, it means that the nerve is completely paralyzed and the body part cannot function at all, like if it had been amputated.

• Incomplete, severe: If the nerve is not completely paralyzed, and there are symptoms like poor blood circulation and muscle atrophy, that seriously limit the body part’s ability to function, then it is rated as severe. The condition must be very severe to be rated here.

• Incomplete, moderate: If the nerve is not completely paralyzed, and there is tingling, numbness, moderate pain, or other symptoms that definitely and significantly interfere with the ability of the body part to fully function, it is rated as moderate.

• Incomplete, mild: If the nerve is not completely paralyzed, and there is only tingling or mild pain in the affected body part, it is rated as mild. There could also be slight or very mild limitations in the movement of the body part, but these limitations would not really affect the overall functioning.

Neuritis

• Severe: If there are all three of the main symptoms (loss of reflexes, muscle atrophy, and loss of sensation), and they seriously limit the body part’s ability to function, then it is rated as severe. The condition must be very severe to be rated here.

• Moderate: If there are one or more of the main symptoms that definitely and significantly interfere with the ability of the body part to fully function, it is rated as moderate.

• Mild: If there are one or more of the main symptoms, but they are mild and do not interfere significantly with the ability of the body part to function, it is rated as mild.

Neuralgia

• Moderate: If there is tingling, numbness, moderate to severe pain, or other symptoms that definitely and significantly interfere with the ability of the body part to function fully, it is rated as moderate.

• Mild: If there is only tingling or mild pain in the affected body part, it is rated as mild. There could also be slight or very mild limitations in the movement of the body part, but these limitations would not really affect the overall functioning.

That’s basically the entire nervous rating system. Each nerve has its own percentages for the various degrees of severity. They will all be addressed in the discussion of each cranial and peripheral nerve.

The Cranial Nerves

The Trigeminal Nerve 

(a.k.a. fifth cranial nerve or fifth nerve) extends from the brain to the face and jaw muscles. It divides into the ophthalmic nerve, the maxillary nerve, and the mandibular nerve. Any condition of these nerves is rated here. The trigeminal nerve provides feeling to the skin of the face, and controls the biting and chewing motions.

A condition of the trigeminal nerve is rated under one of the following codes with the corresponding ratings.

Diagnostic Code 8205: Paralysis of the trigeminal nerve. Complete paralysis: If the jaw is unable to move at all and the skin of the face has lost all sensation, it is rated 50%. Incomplete, severe paralysis is rated 30%. Incomplete, moderate paralysis is rated 10%. There is no rating for mild paralysis.

Diagnostic Code 8305: Neuritis of the trigeminal nerve. If the condition causes severe symptoms, it is rated 30%. If it causes moderate symptoms, it is rated 10%. There is no rating given for mild neuritis.

Diagnostic Code 8405: Neuralgia of the trigeminal nerve. Neuralgia cannot be rated higher than moderate, even if it is considered severe. If the condition is moderate, it is rated 10%. There is no rating given for a mild condition.

Limited motion of the jawbone (mandible) is rated under code 9902 for jaw conditions.

The Facial Nerve 

(a.k.a. seventh cranial nerve) extends from the brain to the face and mouth. It is responsible for moving the facial muscles that are used to make facial expressions, and it helps in tasting.

A condition of the facial nerve is rated under one of the following codes with the corresponding ratings.

Diagnostic Code 8207: Paralysis of the facial nerve. Complete paralysis: If the face cannot make facial expressions, and the ability to taste is decreased, it is rated 30%. Incomplete, severe paralysis is rated 20%. Incomplete, moderate paralysis is rated 10%. There is no rating for mild paralysis.

Diagnostic Code 8307: Neuritis of the facial nerve. If the condition causes severe symptoms, it is rated 20%. If it causes moderate symptoms, it is rated 10%. No rating is given for mild neuritis.

Diagnostic Code 8407: Neuralgia of the facial nerve. Neuralgia cannot be rated higher than moderate, even if it is considered severe. If the condition is moderate, it is rated 10%. There is no rating given for a mild condition.

The Glossopharyngeal Nerve 

(a.k.a. ninth cranial nerve) extends from the brain to the ears, throat, and tongue. It provides feeling to the throat and tonsils, helps sense tastes, and controls the movements of swallowing.

A condition of the glossopharyngeal nerve is rated under one of the following codes with the corresponding ratings.

Diagnostic Code 8209: Paralysis of the glossopharyngeal nerve. Complete paralysis: If it is difficult or impossible to swallow, it is rated 30%. Incomplete, severe paralysis is rated 20%. Incomplete, moderate paralysis is rated 10%. There is no rating for mild paralysis.

Diagnostic Code 8309: Neuritis of the glossopharyngeal nerve. If the condition causes severe symptoms, it is rated 20%. If it causes moderate symptoms, it is rated 10%. No rating is given for a mild condition.

Diagnostic Code 8409: Neuralgia of the glossopharyngeal nerve. Neuralgia cannot be rated higher than moderate, even if it is considered severe. If the condition is moderate, it is rated 10%. There is no rating given for a mild condition.

The Vagus Nerve 

(a.k.a. tenth cranial nerve or pneumogastric nerve) is an extremely important nerve. It connects the brain with all the internal organs in the chest and abdomen. This nerve reports to the brain on the state of the internal organs and how well they are functioning. It does not directly control the internal organs, but just acts mostly as a way for them to communicate with the brain. In addition, it controls the muscles used for speaking and swallowing and is responsible for lowering the heart rate. Damage to the vagus nerve often results in high heart rate (tachycardia) and high blood pressure.

A condition of the vagus nerve is rated under one of the following codes with the corresponding ratings.

Diagnostic Code 8210: Paralysis of the vagus nerve. Complete paralysis: If there is difficulty swallowing and speaking or if the heart or other internal organs are severely affected (uncontrollable high blood pressure, very high heart rate, etc.), it is rated 50%. Incomplete, severe paralysis is rated 30%. Incomplete, moderate paralysis is rated 10%. There is no rating for mild paralysis.

Diagnostic Code 8310: Neuritis of the vagus nerve. If the condition causes severe symptoms, it is rated 30%. If it causes moderate symptoms, it is rated 10%. No rating is given for mild neuritis.

Diagnostic Code 8410: Neuralgia of the vagus nerve. Neuralgia cannot be rated higher than moderate, even if it is considered severe. If the condition is moderate, it is rated 10%. There is no rating given for a mild condition.

The Spinal Accessory Nerve 

(a.k.a. eleventh cranial nerve or accessory nerve) is a branch of the accessory nerve. The root of the accessory nerve starts in both the brain and the spinal cord. The brain branch joins the vagus nerve, and so is rated as the vagus nerve. Only the spinal branch of the accessory nerve is rated here. This branch extends from the brain to the neck and shoulders. It controls the motions of shrugging the shoulders, rotating the head, and tilting the head front-to-back and side-to-side.

Diagnostic Code 8211: Paralysis of the spinal accessory nerve. Complete paralysis: If the shoulders are unable to shrug and the neck is unable to move at all, it is rated 30%. Incomplete, severe paralysis is rated 20%. Incomplete, moderate paralysis is rated 10%. There is no rating for mild paralysis.

Diagnostic Code 8311: Neuritis of the spinal accessory nerve. If the condition causes severe symptoms, it is rated 20%. If it causes moderate symptoms, it is rated 10%. No rating is given for a mild condition.

Diagnostic Code 8411: Neuralgia of the spinal accessory nerve. Neuralgia cannot be rated higher than moderate, even if it is considered severe. If the condition is moderate, it is rated 10%. There is no rating given for a mild condition.

Diagnostic Code 8104: Paramyoclonus multiplex is a condition where the spinal accessory nerve causes the muscles in the neck, shoulders, and upper body to spasm regularly. If it is severe, it is rated 60%. Moderate is rated 10%, and mild is rated 0%.

The Hypoglossal Nerve 

(a.k.a. twelfth cranial nerve) extends from the brain to the tongue. It controls all the movements of the tongue in speech, eating, and swallowing.

A condition of the hypoglossal nerve is rated under one of the following codes with the corresponding ratings.

Diagnostic Code 8212: Paralysis of the hypoglossal nerve. Complete paralysis: If the tongue is unable to move at all, it is rated 50%. Incomplete, severe paralysis is rated 30%. Incomplete, moderate paralysis is rated 10%. There is no rating for mild paralysis.

Diagnostic Code 8312: Neuritis of the hypoglossal nerve. If the condition causes severe symptoms, it is rated 30%. If it causes moderate symptoms, it is rated 10%. No rating is given for a mild condition.

Diagnostic Code 8412: Neuralgia of the hypoglossal nerve. Neuralgia cannot be rated higher than moderate, even if it is considered severe. If the condition is moderate, it is rated 10%. There is no rating given for a mild condition.