Comprehensive Evaluation of CCI and AAI: A Multidisciplinary Approach with Real Clinical Insight

Understanding Craniocervical and Atlantoaxial Instability

Craniocervical Instability (CCI) and Atlantoaxial Instability (AAI) refer to abnormal mobility or instability in the upper cervical spine, particularly at the C0-C1-C2 levels. These conditions often present in patients with hypermobility syndromes such as Ehlers-Danlos Syndrome (EDS), but they can also result from trauma, congenital anomalies, other connective tissue disorders or post-viral or post-infectious syndrome.

When the ligaments and bony structures that stabilize the skull and cervical spine become incompetent, they fail to support the head’s weight and motion, leading to neurological and systemic symptoms. Many of our patients report years of unexplained symptoms before reaching an accurate diagnosis.

“We have pioneered an innovative imaging protocol for evaluating CCI and Tethered Cord that is second to none.”

Symptoms That May Indicate CCI/AAI

Identifying the signs of CCI and AAI can be complex. Common symptoms include:

• Chronic neck pain
• Headaches
• Visual disturbances
• Memory loss or cognitive dysfunction
• Dizziness and vertigo
• Ringing in the ears
• Dysautonomia
• Sleep apnea or choking during sleep
• Numbness or weakness in limbs

These symptoms often overlap with conditions like ME/CFS or Long COVID, leading to misdiagnoses.

“I now walk without a cane, am no longer dealing with constant nausea, syncope, terrible headaches… I get to have dinner with my children, bake sandcakes and do schoolwork with them.”

Advanced Diagnostic Techniques

Proper evaluation requires advanced imaging and expert analysis. In our Barcelona center, we use:

• Upright Cone-Beam CT (uCBCT)
• Prone and supine 3T lumbar MRI for Tethered Cord & arachnoiditis evaluation
• 3T MRV-MRA TOF sequences for vascular studies without contrast

Traditional supine imaging often misses dynamic instability. That’s why we combine anatomical assessment with positional imaging and clinical correlation.

“Craniocervical instability diagnosis is given by performing an Upright Magnetic Resonance Imaging (uMRI), or cone-beam CT scanner (CBCT), that allows for the evaluation of the craniocervical junction in an upright position.”

Clinical-Radiological Correlation

Evaluation isn’t just about imaging. We perform a full clinical-radiological correlation, using measurements (when available) such as:

• CXA (Clivo-Axial Angle)
• Grabb-Oakes
• BAI (Basion-Axial Interval)
• BDI (Basion-Dental Interval)

This allows us to distinguish between craniocervical, atlantoaxial, and subaxial instability, and define the precise segment requiring treatment.

“Preoperative and individualized evaluation of each case is extremely important since anomalies in the anatomy and trajectory of the Vertebral Artery should be ruled out.”

Multidisciplinary Assessment

At Promohealth, our evaluation includes:

• Neurological examination
• Neurophysiological testing
• Genetic and immunological studies
• Pharmacogenetic testing
• Evaluation of associated syndromes (e.g., MCAD, dysautonomia)

This multidisciplinary method ensures an accurate diagnosis, especially in complex cases.

Treatment Options and When Surgery is Considered

Surgical intervention is reserved for cases where conservative management fails. We perform:

• Occipitocervical fusion (C0-C2 and/or C0-T2)
• Atlantoaxial fusion (C1-C2)

Each case is individually assessed to minimize the range of motion loss while stabilizing the critical segments. Surgery is conducted with intraoperative neuronavigation, intraoperative CT scan, neurophysiological monitoring, and Opioid-Free Anesthesia when required.