Extracranial Types of Headache
Headache Resulting from Muscle Spasm. Emotional tensionoften causes many of the muscles of the head, especially those muscles attached to the scalp and the neck muscles attached to the occiput, to become spastic, and it is postulated that this is one of the common causes of headache. The pain of the spastic head muscles suppos-edly is referred to the overlying areas of the head and gives one the same type of headache as intracranial lesions do.
Headache Caused by Irritation of Nasal and Accessory Nasal Structures. The mucous membranes of the nose andnasal sinuses are sensitive to pain, but not intensely so. Nevertheless, infection or other irritative processes in widespread areas of the nasal structures often summate and cause headache that is referred behind the eyes or, in the case of frontal sinus infection, to the frontal sur-faces of the forehead and scalp, as shown in Figure 48–9. Also, pain from the lower sinuses, such as from the max-illary sinuses, can be felt in the face.
Headache Caused by Eye Disorders. Difficulty in focusingone’s eyes clearly may cause excessive contraction of the eye ciliary muscles in an attempt to gain clear vision. Even though these muscles are extremely small, it is believed that tonic contraction of them can cause retro-orbital headache. Also, excessive attempts to focus the eyes can result in reflex spasm in various facial and extraocular muscles, which is a possible cause of headache.
A second type of headache that originates in the eyes occurs when the eyes are exposed to excessive irradia-tion by light rays, especially ultraviolet light. Looking at the sun or the arc of an arc-welder for even a few seconds may result in headache that lasts from 24 to 48 hours. The headache sometimes results from “actinic” irritation of the conjunctivae, and the pain is referred to the surface of the head or retro-orbitally. However, focusing intense light from an arc or the sun on the retina can also burn the retina, and this could be the cause of the headache.
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