Case Presentation: A 25-year-old woman with h-EDS complained of syncopal events occurring systematically when she made cervical extension. Radiological evaluation confirmed cranio-cervical instability due to ligamentous hyper laxity. Radio metrics performed on dynamic cervical MRI in flexion and extension revealed pathological values in the range of motion of the cervical spine. Surgical treatment with occipito-axial stabilization was performed. No postoperative complication occurred. The patient did not experience any syncopal event after the surgery. The reduction in the range of motion was not felt to be disabling by the patient. Postoperative dynamic radiographs confirmed the stabilization of the occipitocervical junction.

Conclusions: Syncope occurring systematically due to cranio-cervical instability in extension may occur in patients with h-EDS. Successful treatment with surgical posterior stabilization of C0-C2 allows to eradicate the disabling symptoms of syncope.

Keywords: Craniocervical Instability; Hypermobile Ehlers-Danlos Syndrome; Syncope; Surgical Stabilization; Case Report

Abbreviations: h-EDS: Hypermobile Ehlers Danlos syndrome; CXA: clivo-axial angle; pBC2: Grabb-Oaks measurement (perpendicular Basion-C2); BAI: basion-axis interval

Introduction

Hypermobile Ehlers Danlos syndrome (h-EDS) is a hereditary connective tissue disorder characterized by joint hypermobility and tissue fragility [1], neurological and spinal manifestations have already been reported [2-4]. Clinical symptoms refer to craniocervical instability with ventral brainstem compression [3,5]. We report a unique case of h-EDS not associated with Chiari malformation that presents disabling neurological symptoms of syncope occurring systematically when the patient made cervical hyperextension.

Case Presentation

A 25-year-old woman with h-EDS was referred to our department for the diagnosis and treatment of repeated discomfort, weakness and syncope in a few seconds after that the patient positioned in cervical hyperextension. The patient complained of increasing episodes of such disabling and bothersome symptoms with time. The symptoms started with discomfort and resolved if the patient stopped cervical spine extension but developed to syncope if the patient maintain hyperextension for more than a couple of seconds. The neurological examination was normal, no sign of clinical deficit, and no cervical medullary syndrome.

The neurophysiological evaluation revealed no disturbance. The radiological examination included standard X-ray of the cervical spine in neutral position as well as in flexion and extension (Figure 1), and cervical MRI in neutral position and in flexion and extension (Figure 2). The patient declared that she could extend more intensively the cervical spine during both exams but avoided to do it to avoid having a syncopal event during the exam. Radio metrics were made on MRI and have included the clivo-axial angle (CXA), the Grabb-Oaks measurement (pBC2) and the basion-axis interval (BAI) [6,7]. The CXA was measured at 138° in flexion, so at the inferior limit of the normal range: no kyphotic instability. The pBC2 was of 9mm, also at the limit for brainstem compression in flexion. The BAI interval between BAI in flexion and BAI in extension revealed craniocervical instability (value in flexion >12mm and interval >4mm) [6,7].

Figure 1: Dynamic MRI evaluation of the craniovertebral junction. Measurements of CXA, pBC0 and BAI were performed on these images in neutral position (left image), extension (middle image) and flexion (right image).

Figure 2: Dynamic X-ray in neutral position (left image), extension (middle image) and flexion (right image) showed marked preoperative occipito-axoidal instability of the craniovertebral junction.

Because of very disabling symptoms of brainstem compression/traction (syncope occurring systematically) and measurements of craniocervical instability at the radiological evaluation, an occipitocervical stabilization was proposed to the patient, who accepted it after extensive information on the benefits and risks of such procedure. The patient was operated on, and a C0-C2 arthrodesis was performed under radiological guidance. Care was taken to preserve ligaments attached to the spinous process and the lamina of C2. No sub occipital decompression was made, since no Chiari was present and symptoms occurred only in hyperextension.

The patient presented no postoperative complication and was discharged the day after surgery. She performed postoperative cervical physiotherapy and was controlled clinically and radiologically at 1, 3 and 6 months after surgery. The patient had a significate reduction of the amplitude of cervical flexion and extension (Figure 3) as well as lateral flexion (Figure 4), but this was clearly considered for the patient as more comfortable than the preoperative hyper laxity related to the h-EDS. The patient did not experience any episodes of weakness and syncope after the surgery, since these symptoms occurred preoperatively several times per day.