Double Crush Syndrome of the Median Nerve: A Literature Review

Double crush syndrome (DCS) is defined as the compressive involvement of the same peripheral nerve in different segments.When this syndrome affects the median nerve, a proximal compression of a spinal nerve that will constitute this structure (often the spinal nerve at the C6 vertebra) is usually noted at the cervical spine level as a herniated disc and as a distal compression at the level of the carpal tunnel. Epidemiological data on median nerve compromise by DCS are still very scarce in the medical literature. The diagnosis can be inferred by symptoms and signs occurring proximally and distally in the arm, as well as by alterations revealed by upper limb electromyography and neuroimaging studies, such as magnetic resonance imaging (MRI) of the cervical spine. Nowadays, information on which compressed neuroanatomical point should be initially addressed still depends on further studies. Limited data infer that these patients, when submitted to surgical treatment in only one of the median nerve compression points, evolve with worse functional outcomes than the surgically-treated group with carpal tunnel syndrome without DCS.

Ultrasound Diagnosis of Double Crush Syndrome of the Ulnar Nerve by the Anconeus Epitrochlearis and a Ganglion

Double compression of the ulnar nerve, including Guyon's canal syndrome associated with cubital tunnel syndrome caused by the anconeus epitrochlearis muscle, is a very rare condition. We present a case of double crush syndrome of the ulnar nerve at the wrist and elbow in a 55-year-old man, as well as a brief review of the literature. Although electrodiagnostic findings were consistent with an ulnar nerve lesion only at the elbow, ultrasonography revealed a ganglion compressing the ulnar nerve at the hypothenar area and the anconeus epitrochlearis muscle lying in the cubital tunnel. Careful physical examination and ultrasound assessment of the elbow and wrist confirmed the clinical diagnosis prior to surgery.

Overlapped multiple distal entrapment neuropathies hindering diagnosis of thoracic outlet syndrome: A case report

Thoracic outlet syndrome is caused by the compression of neurovascular structures at the thoracic outlet region. Diagnosis is difficult since thoracic outlet syndrome is often accompanied by distal entrapment neuropathies such as carpal tunnel syndrome or ulnar and radial neuropathies. In this article, the authors report a case regarding a patient with thoracic outlet syndrome whose diagnosis was delayed due to the overlapping of multiple distal entrapment neuropathies.

A Electrodiagnostic Study on Relationship of the Double Crush Syndrome to Carpal Tunnel Syndrome: a Preliminary Study

BACKGROUND: The concept of "double crush syndrome (DCS)"-a proximal compressive lesion making the distal nerve more vulnerable to injury-is an intriguing hypothesis. However, recent studies did not show unitary results. This study was preliminarily undertaken in order to clarify the causal relationship of proximal compressive lesion and carpal tunnel syndrome (CTS) in an electrophysiologic aspect. METHODS: In the period between June 1998 and June 1999 there were 24 patients with CTS(33 limbs with CTS). With these CTS patients, thorough electrodiagnostic studies were performed to discover coexisting proximal compressive lesions along the median nerve and its corresponding cervical root lesions. RESULTS: In 10 of these limbs (30%), there was a electrodiagnostically-proven coexisting proximal compressive lesion(all cervical radiculopathies). But only 1 limb (3%) had an anatomically responsible association. Finally only 1 limb (3%) with CTS had a possibility of DCS. CONCLUSIONS: CTS and cervical radiculopathy are common disorders, so there is a high possibility of coexisting as a double primary lesion without a pathophysiological relationship. Our results do not support the double crush hypothesis. However, the possibility of a reversed double crush syndrome is suggested.