Double and multiple "crush" syndromes. Double and multiple entrapment neuropathies.

The double crush hypothesis suggests that serial constraints to axoplasmic flow, each of which is insufficient to cause changes in function by itself, can be additive in causing ultimate dysfunction of the nerve. Careful clinical examination will be required to localize the significant levels of nerve compression. Frequently, patients will be asymptomatic in the nonprovoked position. A comparison of neurological testing "at rest" and then subsequent to provocation of the patient's symptoms may be the only mechanism by which the surgeon will be able to quantity an abnormality that corresponds to the patient's symptoms. Surgical intervention, especially when the etiologic factor is work-related, is always postponed until maximum job modification has been carried out. Surgical management of these patients without a significant change in the patient's work habits that provoked the compression neuropathies in the first instance will frequently be associated with a recurrence of symptoms when the work is resumed.