Lesions at this level are usually serious, with causes including stroke or tumor. Second-order neurons leave the spinal cord at T1 and cross the apex of the lung to synapse at the superior cervical ganglion, so they may be vulnerable to chest, neck and thyroid conditions, especially tumors. Third-order neurons travel with the internal carotid artery through the cavernous sinus to the orbit with the third cranial nerve. Several conditions can disrupt third-order neurons, including otitis media and headache syndromes such as cluster and migraine. One review of 450 cases of Horner's syndrome reported that 8 percent were attributable to neoplasm.
Gouty arthritis occurs most commonly in men after the fourth decade of life.
Small joints are the usual site of gout symptoms, with the first metatarsophalangeal joint most commonly affected. Classically, the joint becomes hot, painful, swollen and red. Recurrent gouty inflammation may result in damage to the joint and the formation of tophi. Most attacks of gout resolve spontaneously. Treatment with nonsteroidal anti-inflammatory drugs is usually effective.