Surgical resection of the thoracolumbar sympathetic trunk, widely used in the 1940s in the treatment of hypertension but now of historical interest, provided the clinician with the clearest examples of extensive injury to the peripheral sympathetic nervous system, though a similar defect had long been suspected in one type of primary orthostatic hypotension (see earlier). In general, bilateral thoracolumbar sympathectomy results in surprisingly few disturbances. Aside from loss of sweating over the denervated areas of the body, the most pronounced abnormality is an impairment of vasomotor reflexes. In the upright posture, faintness and syncope are frequent because of pooling of blood in the splanchnic bed and lower extremities. Although the blood pressure may fall steadily to shock levels, there is little or no pallor, nausea, vomiting, or sweating—the usual accompaniments of syncope. Bladder, bowel, and sexual function are preserved, though semen is sometimes ejaculated into the posterior urethra and bladder (retrograde ejaculation).
This disorder, characterized by episodic, painful blanching of the fingers and presumably caused by digital artery spasm, was first described by Raynaud in 1862. The appearance is of a triphasic sequence of color change of pallor, cyanosis, and subsequent rubor of the affected fingers or toes, but about one-third of such patients have no cyanosis. The episodes are brought on by cold or emotional stress and are usually followed by redness on rewarming. Numbness, paresthesia, and burning often accompany the color changes. It is a disease of early onset, the mean age in idiopathic cases being 14 years; it occurs in a number of clinical settings.
Although most cases are idiopathic, in about half there is an associated connective tissue disease, scleroderma being the main one (Porter et al). In these patients, mostly women with the onset of digital symptoms after age 30 years, the Raynaud phenomenon may antedate the emergence of scleroderma or another rheumatologic autoimmune disorder by many years; such disease usually develops within 2 years. In a small group, predominantly men, the syndrome is induced by local trauma, such as prolonged sculling on a cold day, and particularly by vibratory injury incurred by the sustained use of a pneumatic drill or hammer (a syndrome well known in quarry workers). Obstructive arterial disease—as might occur with the thoracic outlet syndrome, vasospasm because of drugs (ergot, cytotoxic agents, cocaine), previous cold injury (frostbite), and circulating cryoglobulins—is a less-common cause. Still, in 64 of 219 patients studied by Porter and coworkers, the Raynaud syndrome was classified as idiopathic, and most of our cases have been of this type. Formerly, the idiopathic form was called Raynaud disease; the type with associated disease is known as Raynaud phenomenon. The presence of distorted and proliferative capillaries in the nail bed, visible with an ophthalmoscope, has been used as a bedside aid to reveal cases of connective tissue disease.
Other processes seen by neurologists, foremost among them carpal tunnel syndrome, also cause cold sensitivity in the fingers. Attacks of digital pain and color change from vasculitis, atherosclerotic vascular occlusion, and other causes of occlusive vascular disease only superficially resemble the Raynaud phenomenon; a search for cryoprecipitable proteins (cryoglobulins) is another cause and a search for these proteins in the blood is appropriate.