Craniocervical Instability

Craniocervical instability occurs primarily amongst hypermobile connective disorders such as Ehlers Danlos Syndrome (EDS). It refers to an excessive degree of mobility in the joints and junctions in the craniocervical area, mainly due to a ligamentous hyperlaxity.

Excessive mobility of the craniocervical junction can affect upper spinal cord and brain stem compression which manifest as a syndrome known as “cervicomedullary syndrome”.  Basically, this is due to the stretching and crushing of the neural elements at these levels and Vertebral Artery flow disturbances.

Symptoms, amongst others, may include headache, neck pain, double vision, memory loss, dizziness, vertigo, speech difficulties, difficulty swallowing.

Diagnosis is mainly made with an Upright MRI evaluation in neutral, flexion-extension and neck rotation. Objectification of direct and indirect signs of abnormal mobility and clinical correlation is mandatory.

Surgical option is the last resort once conservative treatment has been proven to be unsuccessful. Nevertheless, when surgery is recommended it is because there is no other choice other than this to try to improve the quality of life for the patient, that by the way are generally young (thirties-forties).

Surgery may consist of craniocervical posterior fusion, commonly C0-C1-C2. It uses screws, bars, bone harvesting and bone implantation in the surgical area. This fusion limits the areas mobility thus preventing upper cervical spinal cord and brainstem compression at the same time that, while limiting excessive mobility, it makes improvements on the patients’ pain perception.

EDS patients, commonly do manifest comorbidities such as mast cell activation Syndrome, POTS, cardiac anatomic alterations and others. A thorough evaluation should be made in order to know these concomitant diseases prior to the surgical treatment.

Some EDS patients may also suffer from Arnold-Chiari syndrome and/or Tethered cord syndrome.