Double Crush Syndrome

Upton and McComas first proposed the existence of the “double crush syndrome” in 1973.Lancet Aug 18;2. Their hypothesis was that neural function could be impaired when single axons, having been compressed in one region, become especially susceptible to damage in another. (1) They postulated that nonsymptomatic impairment of axoplasmic flow at more than one site along a nerve might summate to cause a symptomatic neuropathy. This was suggested by their clinical observation that the majority of their patients had a median or ulnar neuropathy associated with evidence of cervicothoracic root lesions. Other researches have since reported series of patients supporting the frequent association of a proximal and distal nerve compression syndrome, including carpal tunnel syndrome associated with cervical radiculopathy, brachial plexus compression, and diabetic neuropathy. MacKinnon and Dellon have expanded the description of this syndrome to include a) multiple anatomic regions along a peripheral nerve, b) multiple anatomic structures across a peripheral nerve within an anatomic region, c) superimposed on a neuropathy, and d0 combinations of the above. St Mary’s Hospital/Yale University School of Medicine presents an unusual case of symptomatic nerve compression caused by two nonanatomic structures within an anatomic region. (2)

It has been suggested that this syndrome in some cases is the discrepancy between neurological manifestation and neuro-imaging. Circulatory disturbance in the spinal cord has been considered a possible pathogenetic mechanism of the disorder. (2) In this study in the majority of patients, neurological deficits of the upper extremities did not result from a single peripheral nerve lesion. (207 patient study to clarify the clinical characteristics of double crush syndrome. (3)

A paper titled “Resolution of double Crush syndrome”, “Chiropractic treatment consisting of manual manipulation and physiotherapy can be an effective treatment regimen in the successful treatment of double crush syndrome. For cases of double crush syndrome, chiropractic consideration should be give. “Resolution of double Crush syndrome (J Manipulative Physiol Ther. 1994 Jul-Aug: 17 (6) :395-7

New diagnosis and treatment of thoracic outlet syndrome, double crush syndrome related to thoracic outlet syndrome, and minor traumatic dystrophy related to thoracic outlet syndrome are explained in a paper by Department of Orthopaedic Surgery Japan (4). Studies suggest that practitioners should be aware of double-crush during examination of patients complaining of neck and hand problems. (5) Higher than random coincidence of the two conditions strongly suggests cause-and effect relationship of damage of the proximal stretch of motor nerve fibres and development of peripheral entrapment syndromes in the same nerves rather than a random coincidence of two independent pathologies. Appreciation of this causal relationship is important in the development of comprehensive approach to treatment of peripheral entrapment syndromes. In appropriate cases, simultaneous treatment of the lower back problem should be considered as well. (6)

It is important to preoperatively identify those patients who may have double crush lesions and thus anticipate a less than optimal crush syndrome is present, both entrapments may require treatment for optimal results. (7) The Pronator compression test is a forgotten physical sign. Pronator compression testing is a valuable clinical feature of median nerve entrapment diagnosis In this study more than 50% of the patients had undergone previous carpal tunnel release or were diagnosed at presentation with double crush syndrome. Ten patient in this study and only one patient had a positive electromyographic result, eight had a positive Tinel’s sign at the impingement site. All patients had a good or excellent result from the surgical decompression of the median nerve in the forearm except for one worker’s compensation case who had excellent postoperative strength testing but multiple residual complaints. Pronator compression testing is a helpful and dependable physical sign in the diagnosis of pronator syndrome. . The higher incidence of narrowed cervical foramens in the patients and its concordance with affected nerve roots on the same side as the CTS symptoms support the hypothesis of a double-crush phenomenon. (8) Early intervention with active muscle techniques and spinal adjustment, anti-inflammatory applications including cold applications and electrotherapy have had successful clinic results in a number of cases with positive clinical testing and changes in the cervical spine. Others have been recommended for surgery. (Clinical cases BPHS)

1. Double Crush syndrome: chiropractic care of an entrapment neuropathy. Mariono KA, McDougle MA, Tanksley GW. Island, Honolulu Hawaii 96814 Case Report.
2. The double-crush phenomenon--an unusual presentation and literature review.
Zahir KS, Zahir FS, Thomas JG, Dudrick SJ. St. Mary's Hospital/Yale University School of Medicine, Waterbury, USA
3. Double crush syndrome in patients with cervical spondylosis or ossification of posterior longitudinal ligament – a clinicophysiological study. Hiwa H, Yanagi T, Hakusui S, Ando T, Yasuda T. Department of Neurology, Nagoya Daini Red Cross Hospital.
4. Abe M, Ichinohe K, Nishida J. Department of Orthopaedic Surgery, Iwate Medical University, 19-1 Uchimaru, Morioka 020-0023, Japan.
5. Clinical Trial “Cervical myeloradiculopathy with entrapment neuropathy: study based on the double-crush concept. Baba H, Maezawa Y, Uchida K, Furusawa N, Wada M. Imura S, Kawahara N, Tomita K. Department of orthopaedic Surgery, Fukui Medical School m Japan.
6. PNID: 9553749 PubMed – indexed for Medline) Double crush syndrome in lower extremities. Golovchinsky V. Central Victory Medical Clinic, Van Nuys, CA USA
7. The double crush syndrome. Osterman AL.
Hospital of the University of Pennsylvania, Philadelphia.
{8. The pronator compression test revisited. A forgotten physical sign. Gainor DJ Department of Surgery, University of Missouri School of Medicine, Columbia.