Occipitalis is the posterior belly (part) of the epicranius muscle.
Epicranius refers to the set of facial and scalp muscles. Epicranius has two sections -- frontalis and occipitalis. As you may have guessed, frontalis is the frontal belly of the epicranius muscle and allows the movement of the forehead and eyebrows. Occipitalis is the posterior belly of the picranius muscle and allows the movement of the scalp.
The occipitalis is a thin, quadrilateral muscle that is located at the base of the scalp. It originates in the superior nuchal line, a bone that curves from the external occupital protrubence to the temporal bone. The occipitalis inserts into the galea aponeurotica, the fibrous band that extends over the cranium i.e. skull. The occipitalis allows us to move our scalp backward, which in turn, allows us to lift our eyebrows. It is thanks to the occipitalis that we can wrinkle our brows, and some, can move their ears.
The occipitalis is attached to the occipital bone, found at the base of the skull. Much of the feeling in the back and top of the head is transmitted through the occipital nerves, which run from the spinal cord, through the scalp and to the base of the neck.
There are several medical conditions relating to the occipitalis. Excessive use of the muscle can result in pain and tension. Blunt trauma to the muscle may cause damage leading to facial paralysis, preventing the movement of eyebrows and forehead.
Another related condition is occipital neuralgia, caused by inflamed or injured occipital nerves. Occipital neuralgia may result in pain and tenderness at the base of the head and scalp, pain behind the eye and sensitivity to light. The symptoms may be very similar to symptoms of headache and migraine. The condition is diagnosed through a physical exam and treatment consists of pain relief through the use of over-the-counter pain relief medications, heat application, rest and massage. More serious cases may require the use of drugs such as nerve blockers and muscle relaxers. Surgery is rarely used but is an option when there are problems such as nerve compression. Surgery to decompress the blood vessels (microvascular decompression) or occipital nerve stimulation may be used to regulate electrical impulses and block pain.
Occipital nerve stimulation is a type of therapy that is sometimes used to treat occipital headache and pain that does not respond to other treatments or that keeps coming back. The therapy involves the implanting of a device into the subcutaneous tissues through which a pulse is generated. This therapy may help stimulate and regulate the activity of occipital nerves, and block pain messages from reaching the brain.