The natural history and long-term outcome of 57 limb sarcoidosis neuropathy cases.

Fifty-seven patients with biopsy-proven sarcoidosis causing limb neuropathy were reviewed in order to delineate the characteristic symptoms, impairments, disability, course, outcome and response to corticosteroid treatment of limb sarcoid neuropathy. Typically the neuropathy had a definite date of symptomatic onset. Prominent were positive neuropathic sensory symptoms (P-NSS), especially pain, overshadowing weakness and sensory loss. P-NSS were the main cause of disability. Almost always the pattern was asymmetric and not length-dependent (unlike distal polyneuropathy). We inferred (from kind and distribution of symptoms, signs and electrophysiologic and other test results) that the pathologic process was focal or multifocal, involving most classes of nerve fibers and variable levels of proximal to distal levels of roots and peripheral nerves. Additional features aiding in diagnosis were: systemic symptoms such as fatigue, malaise, arthralgia, fever and weight loss; involvement of multiple tissues (i.e. skin, lymph nodes and eye); the patterns of neuropathy; MRI features; and ultimately tissue diagnosis. Axonal degeneration predominated, although an acquired demyelinating process was observed in 3 patients. For most cases, the disease had a chronic, monophasic course. MRI studies done in later years of affected neural structures were helpful in identifying leptomeningeal thickening, hilar adenopathy; and enlargement and T2 enhancement of nerve roots, plexuses, and limb nerves. Corticosteroid treatment appeared to ameliorate symptoms more than impairments. Several variables were associated with neuropathic improvement: CSF pleocytosis, short duration between symptom onset and treatment, and a higher grade of disability at first evaluation-a possible rationale for future earlier diagnosis and treatment.