Entrapment neuropathies and polyneuropathies in joint hypermobility syndrome/Ehlers-Danlos syndrome

Objective This study aims to investigate the involvement of the peripheral nervous system in Ehlers–Danlos syndromes/hypermobility type patients with particular attention to entrapment syndromes. Methods We consecutively enrolled Ehlers–Danlos syndromes/hypermobility type patients. Patients underwent clinical, neurophysiological and ultrasound evaluations. Dynamic ultrasound evaluation was also performed in healthy subjects as control group. Results Fifteen Ehlers–Danlos syndromes/hypermobility type patients and fifteen healthy subjects were enrolled. Most of patients presented tingling, numbness, cramps in their hands or feet. Clinical evaluation was normal in all patients. One patient was affected with carpal tunnel syndrome and one with ulnar nerve entrapment at elbow. One patient had an increased and hypoechoic ulnar nerve at elbow at ultrasound evaluation. Dynamic ultrasound evaluation of ulnar nerve at elbow showed, in patients, twelve subluxations and three luxations. In the control group dynamic evaluation showed one case of ulnar nerve luxation. Conclusion Statistical analysis showed a significant difference in the occurrence of ulnar nerve subluxation and luxation between patients and control subjects. Significance The study shows an inconsistency between symptoms and neurophysiological and ultrasound evidences of focal or diffuse nerve involvement. The high prevalence of ulnar nerve subluxation/luxation at elbow in Ehlers–Danlos syndromes/hypermobility type patients could be explained by the presence of Osborne ligament laxity.