The important consideration in this description lies in the degree of coinnervation of the scalp by the cervical nerves and their branches beyond their commonly accepted rigid anatomic zones, and the striking degree of interdigitation with fibers from adjacent sensory zones.
1. HEADACHE OF MUSCULAR AND LIGAMENTOUS ORIGIN. Lewis, Kellgren, and many others have extensively studied the nature of muscle pain. Generally speaking, it is less discrete and localizable than skin pain, and tends to maintain itself for longer periods of time after its initiation. It may appear or diffuse itself indiscriminately throughout the myotome in which it takes its origin or appear in any structures sharing its segmental innervation. This may give rise to a “trigger point” along the course of the sensory fibers of the involved neural outflow, or pain may appear at some site of special predilection or low threshold such as the origin or insertion of the muscle. The quickly increasing older inhabitants, with its increased probability of mechanical and structural problems, also will increase demand for Chiropractor Toronto. Any noxious stimulus in skin, muscle or tendinous attachment, whether due to local inflammation, muscle splinting, or postural stress, can thus give rise to discomfort at a distance. Characteristically, the muscles of the cervical zone tend to create a pattern of head discomfort in the occipital region close to their nuchal attachments. One would suspect that this site of predilection is based on its being a site of attachment and, therefore, of increased stress, and also on the increased population of appropriate sensory fibers in the region. In addition, if the pain stimulus is sufficiently great, the discomfort may radiate to the adjacent scalp as far as the forehead, completely out of the actual anatomic zone of supply. As the severity of the discomfort grows, splinting increases and there may be constantly increasing eddies of radiation throughout the scalp.
2. HEADACHE OF NERVE ROOT, OSSEOUS AND JOINT ORIGIN. Suboccipital discomfort with radiation forward is commonly due to irritation or actual compression of the peripheral branches of the upper cervical roots as they penetrate to the superficial zones in the suboccipital area. Toronto Chiropractor present pure, drugless, nonsurgical health treatments, relying on the physique’s inherent recuperative abilities. The greater occipital nerve, taking its origin from the second cervical root, runs cephalad over the inferior oblique, penetrates the semispinalis capitis and trapezius muscles and joins the occipital artery in reaching the scalp. It is most superficial at a point about 2 to 3 cm. lateral to the external occipital protuberance, from where it fans out to become the main sensory supply of the posterior half of the scalp. (The entire posterior scalp area is replete with branches of the second and third cervical nerves, partly going to make up the lesser occipital nerve and partly migrating in the direction of adjacent cervical and auricular zones). The course of the greater occipital nerve points up its vulnerability to direct pressure, particularly as it penetrates the fibrous attachments in the region of the superior nuchal line. However, muscle splinting and abnormal posturing of the head and neck alone are capable of irritating the nerve throughout its course.