Headache of Neurological Origin
The frequent occurrence of headache which is a presenting symptom and often of a disabling nature makes it of great importance for the physician to identify the underlying cause. Too often, headache is treated symptomatically in the presence of unrecognized grave organic disease. The experimental approach to the study of headache has been difficult because of the absence of objectivity of the symptom and the inability of animals to make us acquainted with the exact nature of their sensations.
Elsberg and Southerland,1 in their studies on headache, state that sensory impulses may originate within the cranial cavity, or the primary receptors may be outside the cranial cavity. Pathways must consist of (1) afferent tracts from receptors, (2) a central station, and (3) pathways of pain to the cortex and consciousness.
Afferent impulses must travel along either somatic or sympathetic nerves. The nerves supplying the dura and its vessels are derived chiefly from the trigeminal nerve, the vagus nerve, and the sympathetic system. The dura of the anterior fossa of the skull and the falx cerebri are supplied by branches of the first and second divisions of the trigeminal nerve. The dura of the middle fossa is supplied by the third division of the trigeminal nerve, and the dura of the posterior fossa and the tentorium are supplied by the first and second divisions of this nerve, and by meningeal branches of the vagi. The nerve supply of the dura also includes sympathetic fibers to the blood vessels and meningeal branches. . .