Lateral spinal artery is a pathway by which PICA can be reconstituted in cases of more proximal vertebral occlusion — again recognizing that PICA is a lateral spinal artery homolog — in effect an enlarged lateral spinal artery capturing territory of the cerebellum in addition to the lateral medulla. In this patient, the right vertebral artery is occluded just below the foramen magnum due to dissection. The C1 radiculopial artery (purple) connection to the lateral spinal artery (red) allows for reconstitution of the vermian branch of the PICA (black). The lateral spinal artery below the C1 radiculopial branch is marked with the pink arrow. Notice also presence of the anterior spinal artery (yellow) perfectly contrasting its anterior and medial position to that of the spinal artery. The C1 radicular branch (purple) is in effect the radiculopial artery is acting as a radiculopial artery, homologous to radiculopial supply of the posterior spinal arteries at the thoracic and lumbar levels (see Spinal Arterial Anatomy ) The C1 muscular branch (green) opacifies the occipital artery (white) and deep cervical artery (blue).
For peripheral causalgia, the diagnosis required that the subjects' chronic pain was due to damage to a nerve. The pain was required to be in an anatomical area consistent with the innervation pattern of the damaged nerve (or nerves), and generally, in a hyperalgesic state. In some cases, the nerve damage progressed with secondary changes manifesting themselves. However, this was not a diagnostic requirement. Nerve damage typically resulted from blunt trauma (injury) or other types of injury such as post-surgical nerve cutting or lesioning.