The Greater Occipital Nerve (GON) is a significant sensory conduit in the head and neck. It is chiefly responsible for providing feeling to the largest area of the back of the head. Understanding the anatomy, function, and potential problems associated with the GON is important for recognizing certain common pain conditions. This article explores where the nerve begins, what areas it controls, and how it relates to specific neurological pain syndromes.
Origin and Course of the Greater Occipital Nerve
The Greater Occipital Nerve begins deep within the neck musculature, arising as the medial branch of the dorsal ramus of the second cervical spinal nerve (C2). This places the nerve at the top of the neck, near the junction of the skull and spine.
It first travels upward, emerging between the first and second cervical vertebrae and winding underneath the obliquus capitis inferior muscle. The nerve then continues its ascent, piercing through the semispinalis capitis muscle in the majority of individuals.
After emerging from the deep muscle layers, the GON travels alongside the occipital artery toward the base of the skull. It finally pierces the dense fascia and aponeurosis of the trapezius muscle to become superficial in the skin of the scalp.
Sensory and Motor Innervation Targets
The Greater Occipital Nerve’s primary function is to provide sensory input, or feeling, to a large region of the posterior scalp. It is described as the thickest cutaneous nerve in the body. The nerve’s distribution covers the back of the head, extending upward from the superior nuchal line at the base of the skull.
Its sensory coverage continues over the occiput and reaches forward to the vertex, or crown, of the head. The nerve also contributes minor sensory fibers to the skin just above the parotid gland and sometimes near the ear.
While predominantly a sensory nerve, the Greater Occipital Nerve also possesses a small motor component. It supplies motor innervation to a few small, deep muscles in the neck: the obliquus capitis inferior and the semispinalis capitis muscles.
When the Nerve Causes Pain: Occipital Neuralgia
When the Greater Occipital Nerve becomes irritated, compressed, or inflamed along its course, it results in Occipital Neuralgia (ON). This pain disorder is characterized by discomfort that starts where the nerve emerges in the neck and radiates over its sensory distribution. Symptoms are frequently described as sharp, stabbing, electric-shock-like, or piercing, distinguishing them from the dull throbbing of a typical tension headache.
The pain typically begins at the base of the skull and shoots upward, often affecting one side of the head, though it can occur bilaterally. Individuals may also report a persistent, aching, or burning sensation between the more intense, intermittent shock-like episodes. Sensitivity to light and tenderness across the scalp are common complaints, sometimes making simple actions like brushing hair or resting the head on a pillow painful.
The underlying causes of this irritation are varied but often mechanical, relating to the nerve’s anatomical pathway through the neck structures. A common cause is the entrapment of the nerve as it pierces through the tight connective tissue and muscle fascia of the semispinalis capitis muscle. Chronic neck tension and tight neck muscles can squeeze the nerve, leading to irritation.
Trauma to the back of the head or neck, such as whiplash, can also directly injure the nerve or cause inflammation that results in compression. Other medical conditions, including osteoarthritis of the upper cervical spine, tumors, or blood vessel inflammation, can contribute to the pressure on the nerve roots.
Common Treatment Strategies
The management of pain related to the Greater Occipital Nerve, particularly Occipital Neuralgia, follows a tiered approach starting with conservative measures. Initial treatment often involves non-steroidal anti-inflammatory drugs (NSAIDs) to reduce local inflammation and pain. Applying heat and therapeutic massage can help relax tight neck muscles, such as the semispinalis capitis, that may be physically entrapping the nerve.
Physical therapy is frequently recommended to improve posture, strengthen deep neck flexors, and increase the flexibility of the neck and shoulder muscles. These exercises aim to reduce the mechanical stress placed on the nerve as it emerges from the suboccipital region. For more persistent pain, physicians may prescribe muscle relaxants or certain types of nerve-stabilizing medications.
When conservative treatments fail to provide adequate relief, minimally invasive procedures become the next step, most notably the Occipital Nerve Block. This procedure involves injecting a combination of a local anesthetic and a corticosteroid near the nerve’s path at the base of the skull. The anesthetic provides immediate pain relief, while the steroid works to reduce inflammation around the nerve over time, offering relief that can last for weeks or months.
Nerve blocks are valuable not only for treatment but also for diagnosis; a positive response confirms the Greater Occipital Nerve is the source of the pain. For refractory cases that do not respond to injections, advanced procedures such as pulsed radiofrequency ablation or occipital nerve stimulation may be considered. Surgical decompression to release the nerve from surrounding tissues is reserved when all other strategies have been exhausted.