The double crush hypothesis originally proposed that compression of a peripheral nerve at a proximal site increases its susceptibility to additional distal lesions. The etiology of double crush syndrome is likely multifactorial as mechanical, systemic, pharmacologic, or environmental factors may increase a patient's susceptibility to this syndrome. To date, there remains no standardized definition of double crush syndrome, and there is no consensus on its exact pathophysiology or diagnostic criteria. Patients with double crush syndrome should be counseled that surgical repair may produce inferior outcomes compared with those who are treated for isolated entrapment neuropathies.
